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Crustal structure from a seismic refraction profile across southern British Columbia Cumming, William B. 1977

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CRUSTAL  STRUCTURE FROM A SEISMIC  PROFILE ACROSS  SOUTHERN BRITISH COLUMBIA  William  B. Cumming  B. S c . , U n i v e r s i t y  A THESIS THE  o f Toronto,1974  SUBMITTED IN PARTIAL REQUIREMENTS MASTER  in  REFRACTION  FULFILMENT  FOR THE DEGREE OF OF  SCIENCE  t h e Department of  G e o p h y s i c s and A s t r o n o m y  We a c c e p t to  this  t h e s i s as conforming  the r e q u i r e d  standard  The U n i v e r s i t y o f B r i t i s h March,1977 fc)  William B. Chiming  Columbia  OF  In p r e s e n t i n g t h i s t h e s i s in p a r t i a l an advanced degree at  further  of  the  requirements  the U n i v e r s i t y of B r i t i s h Columbia, I agree  the L i b r a r y s h a l l make it I  fulfilment  freely  available  for  thesis  f o r s c h o l a r l y purposes may be granted by the Head of my Department  of this thesis for  It  f i n a n c i a l g a i n s h a l l not be allowed without my  C^Co^/vyf/'cS  The U n i v e r s i t y o f B r i t i s h Columbia  2075 Wesbrook P l a c e Vancouver, Canada V6T 1W5  Date  or  i s understood that copying or p u b l i c a t i o n  written permission.  Department of  that  reference and study.  agree t h a t p e r m i s s i o n f o r e x t e n s i v e copying o f t h i s  by h i s r e p r e s e n t a t i v e s .  for  <?>-, &(  /A"^T> ^m0 r  i  ftBSTBACT  A partially utilizing  reversed  mine b l a s t s  seismic refraction  as s o u r c e s  southern  British  Valley.  The w e s t w a r d l y d i r e c t e d  short line  extended  330 km  with  were d i g i t i z e d ,  component  relative  filtered,  variation  technigues,  ray theory  while  The FM  and combined  along  least  the reversed  into  and s h o t  vertical  amplitude  the true  the p r o f i l e .  sguares  field  As w e l l a s  delay-time  methods a n d to interpret  data.  Okanagan V a l l e y ,  amplitude crustal  anomalies  refraction  velocity  defined  by s e c o n d  the K a i s e r shot  on  data  point,  c r o s s e s t h e Eocky  the s e i s m i c data  arrivals.  arrival point.  t o 24 km,  with  6.0 km/s  29 km,  data  upper  100 t o 200 km  i s poorer  a velocity  layer  and t h i c k n e s s 9 km i s  recorded  There  and  t i m e and  An i n t e r m e d i a t e c r u s t a l  between 80 and 180 km f r o m f o r a layer  Mountain Trench  show a r r i v a l  i n the approximately  7.05 km/s, d e p t h  of  15  c o n s i s t e d o f 32  s y n t h e t i c s e i s m o g r a m s were used  Where t h e p r o f i l e  of  profile  Instrument  across  t o the Highland  were a p p l i e d i n o r d e r t o d i s p l a y  amplitude  geometrical  the  Sparwood  41 s e i s m o g r a m s .  record sections.  corrections  the  from  p e r i o d s e i s m o g r a m s c o v e r i n g 440 km,  tapes  disc  Columbia  was r e c o r d e d  profile  evidence,  the Highland  west based  Valley  shot  o f 7.35 km/s, a d e p t h o f  and a t h i c k n e s s o f 6 t o 10 km.  The M-  ii  discontinuity depth to  o f 33  t h e west  generally  km  dips  near the H i g h l a n d V a l l e y ,  of the K a i s e r  velocity  i s 7.8  km/s  Kootenay  Lake.  Delay time  165  km  wavelength  anomaly  zone  The  Valley  and  Kootenay  the Eastern  42 km  just  mantle and  suggest t h a t  a  velocity  and/or  Metamorphic  Belt. .  w i t h a deep  study are a p p l i c a b l e  P l a t e a u x and  upper  i n average c r u s t a l  Lakes  approximate  to about  interpretations  i s probably associated  of the p r e s e n t  51°N.  point.  occurs i n the Eastern  between t h e Arrow  Interior  shot  from an  between t h e Okanagan  anomaly  depth t o the mantle The  to the east  transition  Lake.  The  results  p r i m a r i l y t o the  eastern  Metamorphic  Belt  south of  iii  liJIJ  CF CONTENTS  AESTRACT TAELE  . i  CF CONTENTS  .  i i i  L I S T CF TABLES  iv  LIST  V  CF FIGURES  ACKNOWLEDGEMENTS  vi  C HAFT EE I  1  1. A c t i v a t i o n 2. E e g i o n a l 3.  ....................................... 1  Geophysical  CHAPTER  Review  .........10  II  1. Data  .  16  Aguisition  2. P r e l i m i n a r y CHAPTER  . . . . 4  Geology  ......16  Analysis  25  III  .  1. P r e l i m i n a r y 2. Near  Interpretation  35  Source C r u s t a l  Profile  from H i g h l a n d  3. Near S o u r c e C r u s t a l  Frcfile  frcm  4.  Synthetic  Seismcgrams  5. l e a s t - S g u a r e s 6. l i s c u s s i o n 7.  Conclusions  L I S T CF REFERENCES  Delay  Times  35  Kaiser  Valley . 4 1 47 .....52  ........................ 6 4 ......72 77 79  iv  IIST  Table  1.  Table  2a.  Kaiser  Table  2b.  Highland  CF TABLES  Shot S t a t i s t i c s Station Valley  18 Statistics Station  Statistics  ........21 23  V  LIST  Figure  1.  Geological  Figure  2.  Kaiser  Figure  3.  Highland Valley  Figure  4.  Near  Figure  5.  Travel  Figure  6.  Near  Travel Figure  CF FIGURES  and S t a t i o n L o c a t i o n  Record  Source  .......3  Section  29  Record  Section  Highland Valley  Tiroes, T o p o g r a p h y ,  Source  Raps  31  Section  ........ 33  And G e o l o g y  Highland Valley  Section  37  with  Time C u r v e s  7.  Schematic  42 o f Near  Source  Kaiser  Seistnic  Structure  50  Figure  8.  Kaiser  Figure  9.  Synthetic  Model Figure  of Kaiser  10.  Section  With  T r a v e l Time  Seismogram  Section  Curves  .....54  And V e l o c i t y  Profile  ..56  Highland V a l l e y Section  with T r a v e l  Time  Curves Figure  59  11.  Model  Synthetic  seismogram  s e c t i o n And V e l o c i t y  of Highland Valley P r o f i l e  61  Figure  12a.  D e l a y Time S o l u t i o n F o r A P l a n e  66  Figure  12b.  D e l a y Time S o l u t i o n  68  With  One F o u r i e r Term  ACKNOWLEDGEMENTS  The  guidance  C l o w e s , h a s been read  greatly appreciated.  the manuscript  deserves  technical preparation  Chris  Meldrum  and p r o v i d e d  Clayton,  George S p e n c e , provided  The  Ellis  assistance  and c o m p a n i o n a b l e  Basil  who  also  acknowledgement  and w i t h  also  thanked  Peters,  Stan  shot  f o rtheir  data.  fortheir  Mining  work  S u l e , Bob  Knize  and S t e v e n  assistance. Resources,  companies  cooperation  The p e r s o n n e l  help  field by Ecb  Peter  and management o f K a i s e r  Copper, and Lornex  site  Messrs.  enthusiastic field  personnel  Bethlehem special  field  R.M.  West, a n d t h e t e c h n i c a l c l a r i f i c a t i o n s were much a p p r e c i a t e d .  Malecek  Dr.  Dr.R.M.  thanks.  The of  and a s s i s t a n c e o f my s u p e r v i s o r .  deserve a t the blast  o f Cominco L t d . a r e  i n the f i e l d  and m a t e r i a l  assistance. The Dr.  use o f t h e s y n n t h e t i c s e i s m o g r a m  R.A. W i g g i n s  was much a p p r e c i a t e d .  programs p r o v i d e d Eranch Dr. John  by C.A.G. F o r s y t h  and m o d i f i e d  Larry  The  The t i m e - t e r m  o f the Earth  were  George Spence, Stevs  programming authors  a s s i s t a n c e and  understanding  Physics  appreciated.  L i n e s , G e o r g e McMechan, Tim A h e r n ,  C. D a v i e s ,  provided  by t h e a u t h o r  programs o f  Rob C l a y t o n ,  M a l e c e k , and Mat Y e d l i n suggestions.  o f t h e geology  of the  Canadian Dr.  R.  Cordillera  Survey  clarified  A r m s t r o n g , I a n Hunt,  Department British  was  of Geological  C o l u m b i a , and of  Dr. C.  with  Godwin o f t h e  Sciences a t the D n i v e r s i t y of  E r . G.  Eisbacher  of t h e  Geological  Canada.  Special keypunched  and  in discussions  appreciation  i s due  my  wife  Yasmin,  t h e d r a f t s and e n c o u r a g e d a h e a l t h y  whc  academic  perspective. This Council  project  was  c f Canada,  Fatroleum  by  t h e Department  R e s o u r c e s o f Canada, Mines and  supported  and  the N a t i o n a l  o f Energy, Mines  the B r i t i s h  Resources.  Research  Columbia  and  Department  1  1.  Motivation  A reversed Kaiser  profile  between  R e s o u r c e s s t r i p c o a l mine n e a r S p a r w c o d ,  C o l u m b i a , and i n the  seismic refraction  t h e L o r n e x and  Highland  V a l l e y , was  begun i n 1973.  Columbia's  b l a s t s as e n e r g y s o u r c e s .  T h i s work e x t e n d s  c o v e r a g e t o t h e w e s t c f an  earlier  the  present  t h a t are  the  study  (Bennett  et a l . , 1 9 7 5 ) .  crosses outstanding especially  i n e x p l a i n i n g the For  at depth. be  exactly  profile.  with the  major  on  ore  (Kanasewich,1969) However,  g e o p h y s i c a l m o d e l s o f t h e u p p e r m a n t l e and r e g i o n , based mainly  gravity  profile  of  evidence,  Any  deep  economically  example, Cominco's S u l l i v a n rift  The  geological features  formation of  r e l a t e d t o a Frecambrian in line  may  mine  seismic  pcint for a northwesterly p r o f i l e along  expression of surface v a r i a b i l i t y  deposits.  utilizing  the  poorly understood,  important  seismic  which used  Rocky Mountain Trench  study  mines  It is a  s t u d i e s i n the Canadian C o r d i l l e r a  K a i s e r shot  British  B e t h l e h e m open p i t c o p p e r  c o n t i n u a t i o n of the U n i v e r s i t y of B r i t i s h structural  the  mineral body has and  been  i t is  previous crust across  h a v e had  very  this  2  little  corroborating  mining  companies  relatively  2.  The which zones is  platform  profile 1).  the  At  first  ending  sheets  have been  basement  i n the  eastern This  shield-type  Rocky  sedimentary deformation,  the  the  utilize  the  i n v e s t i g a t i o n of  the  has  a  area  was  In  Kaiser  shot  overlain several  Mesozoic, low  passive  sediments.  a r i s e n over  The  by pulses  and  angle  of  from t h e  most  thrust is  Ranges, a  crystalline However,  degree  of  basement  Western  shortening  c o n t r o l l e d by  shortening  the  the  of  There  Front  Main and  lateral  degree o f  distance  the  point  once a s t a b l e  easternmost  section i s partially  boundary  the  recks  i n the  largely  within  several geological  end,  t h r u s t i n g in the  the  Columbia  p r o g r e s s i v e l y eastward.  Mountains.  and  Eritish  Eocene, a s e r i e s of  overthrust  debate  westerly  shelf-slope  to  seguences.  stacked  involvement i n the  minimum  the  beginning  separates  from  considerable  the  southern  agreement t h a t , i n the  decollement  of  of  sedimentary  recent  general  offered a  i s located cresses  Hudsonian  miogeoclinal activity,  statistics  in a seismic  Rocky M o u n t a i n s . of  of  Geology.  (Figure  i n the  shot  cooperation  region,  narrow r e g i o n  the  The  opportunity  l a r g e shots  understood  Regional  data.  in obtaining  inexpensive  exceptionally poorly  seismic  will  of  Ranges  the  basement constrain  the  Prcterozoic continental  present  western  margin of  the  Figure  1.  Upper map: modified lower  map  Lower map: Highland  Geological The from  the  station  regionalized Stacey  The  open  Valley  and  with  and  heavy  of  is  the  lines.  circles  represent  sites  Alpha-numeric i d e n t i f i c a t i o n of  of  Network s t a t i o n normalization.  maps.  zone map  area  recording  s i t e s i s explained  location  The  closed  Kaiser  location  geological  (1973).  i s outlined  respectively. recording  and  the  Canadian  which  was  i n the  text.  Standard  used  for  PNT  Seismic  amplitude  is  INTERIOR PLAINS  5  Pocky  Mountains.  Campbell  north  of l a t i t u d e  55° at l e a s t ,  deformed all  i n t h e Main  the  Ranges  interpretations (1970)  and  would  widely  decollement  well  the  Eastern  Metamorphic  200  km  would  of s h o r t e n i n g  day  Arrow  Lake.  c o m m u n i c a t i o n , 1977) half  occurred  of t h i s north  are  physiographically  difficult these  with  Columbia. boundary Rocky  the p r o f i l e ,  that  Mountjoy  the shortening  along  from  which  west  of the  (personal i s l e s s than  are terminated t h e Main  a line  Therefore,  into  a s much a s  zone,  assemblage  Ranges  approximately  i t would  this  to  be  study to  resolve  Mountains.  o v e r 1600  km  f r o m Montana  to northern  I t forms a sharp p h y s i o g r a p h i c the g e n e r a l l y  imbricate  M o u n t a i n s t o t h e n o r t h e a s t , and  Purcell  and  M o u n t a i n T r e n c h i s an i n t e r m o n t a n e v a l l e y  between  structure  only i n  Mountains,  study, while  truncated  o f t h e Reeky  The Rocky extending  slope  t o use t h e i n f o r m a t i o n  models  Price  implies  W e s t e r n Ranges  c f the' a r e a o f t h i s  coincident  Mountain  C a m p b e l l and E i s t a c h e r  The  the  and  i n the t h r u s t  shelf  and i n  They e x t e n d t h e  This  suggest that  amount.  Ranges,  However, t h e  c f t h e Rocky  Belt,  been  his interpretation  accepted.  place, the . o r i g i n a l  present  fit  e t a l . (1966)  t o t h e west  has  o f t h e Rocky  the F o o t h i l l s .  of Bally  are s t i l l  t h e basement  t o t h e west  A deccllement  front  s u g g e s t s t h a t , t o the  R a n g e s , i n t h e Western  of the mountains  Trench.  (1973)  of the v a r i o u s  and  British  geologic  structure  t h e more  complex  ranges to the southwest.  M o u n t a i n s a r e bounded  by t h e t r e n c h  cf the  at the  The latitudes  6  of  this  study.  a s e r i e s of echelcn"  ranges  fault  The  as  north  In  freguently  reflects  trench  mark an  may  reasserted  itself  However, t h e  and  of  be  very  do  The  may  of  suggestion  of  the  geology  "veneer"  be the  cnly along t o be  the  related to  consistent  with  extensional  Purcell  indirectly  and  of  the  the  by  such  a  physiographic the  structural extensional the  eastern  preferred  feature  between west  in the  part  a recent  east  of  a  underlying  only  the  vary  i s of  t o Eocene boundary  has  Although  Therefore,  to the  Any  proximity  trench  "the  veneer."  detectable  coincidence.  last  that,  that  difficult.  may  gracen,  trench  makes even  Miocene,  be  the  allocthonous  very  The  origin  the  a  "en  a thrust  the  the  deformation  structures  fault,  makes t h e  (1965)  i n an  different  trench  have c h a r a c t e r i z e d t h i s  late-Mesozoic  truncates  been a  the  indirectly  be  seem  since  interpretation  ductile  the  formations  that  Cordillera  i n t e r p r e t e d by  o l d , deep f r a c t u r e zone through  i t may  they  tectonics  a  Leech's  More i m p o r t a n t l y ,  may  geological  T r e n c h has  erosional feature.  to  tectonic feature  inference.  detail,  as  complexity  reconstruction  trench,  been  persistence of  Speculation  boundary  Mountain  a purely  unlikely.  trench  Metamorphic B e l t  a half-graten, a transcurrent  and  vestigial  the  Montana i t a p p e a r s t o be  i t has  s t r u c t u r e , or  linearity  Eastern  Rocky  structure.  i n the  authors  i n the  fashion.  enigmatic while  However, f a r t h e r n o r t h ,  expressing  brittle  respectively.  and Deep  involved.  A n t i c l i n o r i u m i s a t h i c k sedimentary  wedge  7  separating Mountain  the  Eastern  Trench i n southern  simplification, Metamorphic  Belt  as  generally the  shallow  characterized deeper  water  as  water d e p o s i t s  the  i n the  in  P u r c e l l Group e x p e r i e n c e d  the  orogeny  Racklan  involving  the  deposited. and  a  this  area The  region from  by  the  rocks,  the  entire  intruded,  structures almost  Eastern  which  Mesozoic.  ( B a l l y et  profile  i t s high  This  southwestern  the  altered  and  deformed  basement r o c k s . "core  zone" of  activity  The the  appears to  late-Mesozoic have o c c u r r e d  was  then  during  models  of  basement  in  deformation. the  central  metamorphism often  and  called  the  particularly in i t s  sedimentary,  i s usually  Group  distinguished  Shuswap Complex  volcanic, region  is  area,  i s dominated,  by  the  i n the  run,  Omenica C r y s t a l l i n e B e l t , sections,  section  which f o r m s  was  in  was  Windermere  Despite  degree of  granitic intrusion.  i t  a l . , 1966),the  Belt,  The  also  metamorphosed  c e r t a i n l y involved  the  P u r c e l l s by  mildly  to  sections.  sedimentary  and  Metamorphic  grading  probably  Unccmformably o v e r l a i n  was  widespread  mya,  which  across  the  800 cn  phases i n the  decollement  to  assemblage,  deformation  basement  thrusted,  s e r i e s of  1000  crystalline  Paleozoic  folded,  from  west  and  are  slope  mild  a  (Wheeler  more e a s t e r l y  Proterczoic  As  Purcells  the  Rocky  Eastern  range  a continental  sediments  the  i n the  truncated  sediments of  from  Columbia.  included  another  The  Eelt  British  i t i s often  Gabrielse,1972).  with  Metamorphic  of  and,  referred  deformation. m a i n l y i n the  intensely perhaps, to  The  as  the  thermal  Jurrasic,  8  followed  by  a milder  metamorphism, the recently Of  particular  represent  Eessor,  Mountains t h a t (personal  the  with  along  an  considered  relatively western  Another  from  "suture" obvious  this  i n the  Okanagan the  zones  the  of  not  the  a  Rocky  Duncan  that a tectonic (or  transform)  agrees  with  models i n v o l v i n g -  the  the  geological primarily  present  more i n t e n s e  Eastern  Plateaux.  The  The  study,  zone,  the  although Interior  a r c , and  of  Metamorphic this  i t forms Plateaux  group of  rocks.  Belt.  generally  Eastern  nature  is  metamorphism  Metamorphic  undefcrmed  v o l c a n i c sedimentary island  beneath  feature  Valley, separates  basin,  probably  surface.  tectonic "suture"  relatively  gneisses,  (Monger e t a l . , 1 9 7 2 ) .  g e o l o g i c a l boundary.  of ocean  only  apparently  zone b e t t e r  complicates  the  are  transcurrent  doubt,  and  intense  basement  suggested  i s i n considerable  plutonic,  the  previous  pattern  Interior  h e t e r o g e n e o u s , but  typical  has  region,  s e c t i o n of  proposed  the  granitoid  rocks  to  "suture"  than  of  rocks  i n t e r p r e t a t i o n of  simple  zone has  crystalline  These  subduction  of  of  Lake, t h a t  shield-type  considerably  reconstruction  Eelt  the  evidence  this  the  1974).  Arrow l a k e  Although  along  Arrow  a major P a l e o z o i c  dipping  the  with  have been b r o u g h t  eastward  in  of  this  i s a belt  communication,1977)  structural  the  interest  r e m o f c i l i z s d Hudsonian  extension  geometry  of  Because  understood.  coincident  (Wanless and  fault  substructure  become b e t t e r  approximately  simple  T e r t i a r y event.  an is a  volcanic,  These r o c k s  successor  basin  are  9  settings.  By a complex  subducticn,  seme o b d u c t i o n ,  movement, t h e r o c k s into  their  present  Metamorphic et  Eelt  a l . , 1972).  different  position  of this  Highland  Valley  Mesozoic  grancdiorite  1S73).  intrusion.  or  "core  In  order  margin pcints  Mesozoic  (Monger  much o f t h e c o n f u s i o n i n t h e  of the I n t e r i o r l i e around  Guichcn  Creek  (Northcote,  1969).  i s apparently  to i n v e s t i g a t e on i t s e a s t e r n  recording  sites  P l a t e a u x , the  the core  batholith The g r o s s  from  t o be a t i l t i n g  emplacement  volcanics  pcints.  to the Eastern  I t s v a r i o u s phases roughly  mineralization  brought  area.  I t appears  zone"  were  of o l d f e a t u r e s i n  has been d e t e r m i n e d  t h e most r e c e n t  sotre t r a n s c u r r e n t  the e a r l y  and v o l c a n i c s e d i m e n t s .  batholith  with  shot  causes  dipping  Plateaux  relative  sometime d u r i n g  Near t h e w e s t e r n  al.,  and p r o b a b l y  of t h e I n t e r i o r  modes p r o b a b l y  volcanics  of eastward  The r e a c t i v a t i o n  interpretation  the  process  zone o f t h e  which  s t r u c t u r e of  gravity funnel  data  approximately  ether,  i n the centre  The d i s s e m i n a t e d  the b a t h o l i t h ,  (Ager e t  shaped  encase each  a s s o c i a t e d with  intrudes  copper  the core  and t h e N i c o l a  margin, a g r e a t e r d e n s i t y o f  was us€d n e a r  the Highland  Valley  shot  zene.  10  3•  Geophysical  The cf  Review  Cordillera  in British  et a l . (1971).  i n Berry  t h e r e a r e few m a n t l e  depth  o f 30 t o 35 km 1973).  slightly  more dense m a n t l e ,  central  Cordillera  adjacent  boundary British placed  developed  running  data  southwest  33  s l o p e d from  45 km b e n e a t h  t h e Rocky M o u n t a i n s ,  mantle  from  by  et al.(1975)  At t h e w e s t e r n et  a l . (1968)  over  a 6.1  found  A mantle  strike  was p r o p o s e d .  7.8  dense c r u s t  i n the than  Rocky  and t o t h e n o r t h t h e A deep  Mountain  mantle  Trench  of t h i s  crust:  a 5.2  that apparently d i r e c t l y  discontinuity  near  between  . study, km/s  White  layer  o v e r l i e s the east-west  change  km/s t o t h e n o r t h i n a  model had t h e m a n t l e  50  i s confirmed  5 0 ° w i t h an  One mcdel had a v e l o c i t y  The a l t e r n a t e  I t was  Plateaux to  and Spence e t a l . (1 977)  t o 8.1  i n southern  to northeast.  km i n t h e I n t e r i o r  a three layer  km/s i n t h e s o u t h  30 km deep.  model w i t h a  Mountain Trench,  end o f t h e p r o f i l e  km/s c r u s t  mantle.  crustal  data  was s u g g e s t e d  33 km t o 53 km.  60 km i n t h e n o r t h e r n Bennett  data  To t h e s c u t h , t h e M-  discontinuity  and  seismic  A vague m a n t l e d e p t h - v e l o c i t y - d e n s i t y  between 49°N and 5 1 ° N .  dipped  out that  an a v e r a g e  a gravity  and a l e s s  on t h e g r a v i t y  Columbia  from  although  west o f t h e Pocky  regions.  based  They p o i n t e d  was i m p l i e d by g r a v i t y  (Stacey,  Stacey  much o f which i s  daterminations  t h e E a s t e r n Metamorphic B e l t ,  thickness  in  has been t h e s u b j e c t  considerable geophysical investigation  summarized  in  Columbia  from  mantle  depth  11  changing a  from  uniform The  mantle  shallower complex  upper  Regional  amplitude  becomes l e s s the  o f 7.8  Time-term  mantle boundary  topography  than  limited  Eelt.  km/s  In the  increases to  i n the south,  profiles  data  reveal a  with  a less  n o r t h o f 5 0 ° 30'N. that the M - d i s c o n t i n u i t y  t o the southwest  c f Kamloops, than  to  northwest. Using  tendency  s u r f a c e wave d a t a ,  to a sharper  40 t o 50 km  discontinuity thicker  Wickens  crust-mantle  east of the Highland  layer  thick  Valley  and a b o u t  i n the I n t e r i o r  and d e e p e r t o t h e n o r t h  f o r the region  character  lies  t o 8.0  km/s  Although surface,  along  mantle  the p r o f i l e ,  the upper c r u s t  i t i s reasonable  found  velocity t h e «-  t o become  wickens  also  by t h e p r e s e n t  s t u d i e s suggests  boundary  and an a v e r a g e  A low  velocities previously  investigated  A g e n e r a l s y n t h e s i s of previous  was  a  t o the north  15 t o 20 km b e n e a t h  and e a s t .  suggested  d i p p i n g upper  point.  Plateaux,  t h e g e n e r a l l y low m a n t l e  gently  (1976) c o n f i r m e d  transition  shot  confirmed  7.8  but with  (1975),  interpretations  s t u d i e s suggest  distinct  with  in British  and F o r s y t h  Metamorphic  velocity  kir/s n o r t h o f 5 1 ° ,  transition  Cordillera,  f a r e a s t as t h e E a s t e r n  i n the south,  km/s.  s t u d i e d by B e r r y  i n the western  southwest,a  and  o f 8.0  t o 28 km  of the crust-mantle  has been  primarily  8.1  i n the north  Fn v e l o c i t y nature  Columbia  as  33 km  that a  , perhaps of v a r y i n g  with  depth  study.  a velocity  o f 35  i s extremely  of about  km. complex  t o assume t h a t i t has  at the  relatively  12  smooth a n o m a l i e s near mantle d e p t h s F c r s y t h , 1 975) .  Fairly  of the c r u s t a l crust  simple  refraction  models  results,  west o f t h e I n t e r i o r  (Berry  have a c c o u n t e d f o r most  w i t h a 6.5  Plateaux  average c r u s t i n the eastern  grading  Cordillera.  suggested that the s e i s m i c r e f r a c t i o n unable to detect evident study,  frcm this  a crustal  surface  discontinuity.  pointed  refraction The  The  Rocky  (1976)  that  was  In the r e g i o n of  zone a p p a r e n t l y  bottomed  o u t , i t w o u l d be d i f f i c u l t  between  a n o m a l i e s was  M-  to g i v e  results,  to detect  as with  the major g e o l o g i c a l d i v i s i o n s  described  a s h a r p c o n t r a s t between  by H a i n e s e t  al.(1971).  guiet Eastern  The  Plateaux  Interior  Metamorphic  i s relatively  small scale anomalies. discontinuity  t h e b r o a d smooth  boundary  anomalies  o f t h e C a n a d i a n S h i e l d t o t h e e a s t , and  magnetically  a l . (1971)  this  a t the  Mountain Trench forms t h e major magnetic  characteristic  The  Rocky  B e l t t o the  guiet with  Mountain  the  west.  patches cf  Trench  has b e e n e x t e n s i v e l y i n v e s t i g a t e d by C a n e r  using  geomagnetic  depth scunding data.  et  The  m a g n e t i c c o m p o n e n t , Z, h a s a marked d i s c o n t i n u i t y  j u s t t o t h e west  c f the t r e n c h , with  low Z t o the west. the  zone  M-depths from r e f r a c t i o n  correlation  magnetic  vertical  Wickens  km/s  data.  and  with  average  t o a 6.1  A l t h o u g h such a f e a t u r e would tend  anomalously shallow Wickens  km/s  e x p e r i m e n t s were  low v e l o c i t y  wave s t u d i e s .  lew v e l o c i t y  and  trench  frcm  This  the north  high  Z to the e a s t ,  feature apparently until  runs p a r a l l e l  i t reaches the north  end  and to of  13  the  Purcell  along high  the  A n t i c l i n o r i u m where i t f o l l o w s t h e  western  margin  conductivity layer  transition hydrated  was  proposed  rock.  Caner  west  t r e n d i n g anomaly  this  marked  conductive  either upper  new  data,  Precambrian southern  offset  put  rift  Alberta into  Riddihcugh  Trench appears low  and  to the  the  the  i n the  suggestion  magnetic  flow  eastern  the  (Reitze^. et  deeper,  of  of  to the  e a s t and  in  the from  Berry  Berry Rocky  of  the  rift  magnetic and  Forsyth  et a l .  (1971)  Mountain  Trench  and  margin. may  area  of the  moderately  of  and  particularly  f o r the  Purcells,  o b s e r v a t i o n s than  margin  layer.  interpretation  extension  anomalies  The  that  A n t i c l i n o r i u m might  t h a t the  cratonic  east-  highly  extension  a l . (1969) t o a l l o w  Gough,1975).  found  an  conductive  structures,  t h a t an  Using  (1971)  to experience  values  U.S.A.  the  thermally  suggested  of the  crustal  Purcell  data.  mark the  to heat  (Camfield  of  anomalies  However, t h e related  margin  (1973) a l t e r e d  the  (1975) r e a f f i r m e d t h e  in fact,  of  Arc  crustal  west o f  zone o f Kanasewich e t a l . ( 1 9 6 9 )  Kanasewich et  did,  n o r t h o f 49°  suggested  zone o f  and  to the  the c o n d u c t i v i t y l a y e r  some o f t h e  Law  I t would c o n s i s t  i n the  Dragert  also  geological  .  t i e northern  explain  and  deep  and  complexity  He  t o 40  just  increased west.  15  proposed  He  the  km  A deep  e t a l . (1971) a l s o  Caner e t a l . the  Purcells.  mantle r e g i o n i n the  a l . , 1 9 7 0 ) , o r an Using  of the  Kcotenay  be  closely  to s t r u c t u r a l  from Coast  high heat west  more  the  Rocky  models Mountain  Metamorphic  Belt  f l o w , compared  ( J e s s c p and  Judge,  to  14  1971).  A.M.  Metamorphic northern  Jessop Belt  and  U.S.A.  magnetic  since  tectonic  the middle  recent thermal  features.  Mountain  The  Trench  tectonic  feature  Bally  Rocky  high  work t h r o u g h  velocity  west.  The  an  Purcell These  cider  in  point.  than  related  to  cr indirectly  t h e Main and Trench  seguence  km/s)  the  with  this,  related ancient  detailed  reflection  and  a c r o s s the  latitudes  (6.1 km/s), c o v e r e d  i n the  east,  often  are thrust  and  into  overthrusting  p a s s i v e basement  The  of  agrees  o r Windermere s e d i m e n t s  of the  to  Proterozoic  interpretation described  the  of  In t h e F r o n t Ranges t h e y f o u n d  2° t o t h e w e s t .  Mountain  anomalies,  thermal  unlikely.  seguences  layer  interpretation shot  study.  Paleozoic  relatively  about  directly  the Rocky M o u n t a i n s ,  (4,0 t o 4,6  Frecambrian  with  t o be  the  i t seems t h a t  T r e n c h , at a p p r o x i m a t e l y the  of t h i s  Mesozoics  the  Mesozoic,  e t a l . (1966) i n t e r p r e t e d  Mountain  profile  i s not  anomaly  undergone i n t e n s i v e  previously  a coincidentally  the  area, p a r t i c u l a r l y  preferred  although  seismic  has  the s o u t h e r n E a s t e r n  e x t e n s i o n of  thermal  this  d a t a i s more l i k e l y  relatively  Rocky  Belt,  that  a r e an  Mountain  Because  Metamorphic  alteration  suggested  Purcells  Rocky  (Blackwell,1969). Eastern  has  from  e x t e n s i o n of t h e i r Western  Ranges, and  where t h e d a t a was  in  imbricate sheets  slopes  stations results  was  sequence. gently  important near t o the  a c r o s s the poor,  by  (5.5 km/s)  T h i s i n f o r m a t i o n was arrivals  a  overlying  a ycunger  (6.5 km/s)  the  the  i n the Kaiser  northwest  Reeky  doubtful.  15  Integrating interpretations are  geophysical  is difficult,  rapidly evolving,  geophysical prominent Mountain (since  Trench  evidence  should  be  to  to  survive.  misleading,  since  movements p a r a l l e l geologically  to  important  vertical  cn  these  prescribed regular  be  used  to to  crustal features  constraints resolve  can  the  clear  the  data  s t a t i o n spacing  of  The  most  west  the  Rocky  of  fairly to  recent  rely  should  evidence strike  subduction the  with  Berry  and  strike.  define  a signal-to-noise  the  be  on  large  the  previously In  and  ratio  order  Forsyth of  l e s s than  better 20  km.  direct  also  lateral  as  other  scale  with  are  that  Long  invoking  little  are  events  approached  reconstructicns  tectonic  models  terms.  might a l l o w  interpretation.  structures,  what  of t e c t o n i c a c t i v i t y  i s growing  as  geological  tendency  episodes  the  movements p e r p e n d i c u l a r refraction  The  Tectonic  there  the  r e l a t a b l e to  years  orogenic  geological  in tectonic  model t h e  billion  intense  since  anomalies to  mid-Mesozoic).  two  and  i t i s not  represent  structures  care;  several  data  and  geophysical  the  ancient with  the  compressional  range  seismic  lateral  and  described to  successfully  (1975) than  2,  and  a  16  CHAPTER  1.  Data  Aguisitiqn  The in  by  from  to  30  levels  seven the  dB,  FM  of  site,  a two  and  WWVB t i m e  high  and  radial time  A crystal  signal,  and  timing.  channel  of  The origin  Fcr  some o f  the  and  t i m i n g was  of  the The  chart paper time  100  dE.  the  high  on  decimal  system  m of the  c f 4 cm/s  reducing  gain  with  coded  blast  monitoring  operator  by  gain  were r e c o r d e d  point  20  In  separated  Both  KWVB b i n a r y  to w i t h i n  by  levels  50  Mark  Hertz.  clock synchronized  shot  B  AS330 s e i s m i c  signals  recorder speed  Willmcre  components,  within  s h o t s , no achieved  gain  A,  recorded  o f one  Geotech  described  designated  transverse  output  two  are  a m p l i f i e d and  the  a geophene p l a c e d  signal.  deterrxination  site  tape.  provided  systems  and  coaximum g a i n  vertical  consisted  system  survey  a n a t u r a l freguency  and  a  r a d i o time  signal  Three  radial,  component, and  channel  in this  dynamic r a n g e ,  with  f o r the  KRV  time  with  have lew  transverse  Each  vertical,  to extend  amplifiers  used  B e n n e t t (1973).  seismometers  order  18  systems  C were d e p l o y e d .  signals II  seismic  detail  and  II  i t and  allowed  the  a  ms.  was  at the  arrival  blast  times  from  17  the  FK  tapes  Eevelstoke, Seismic  of or  on  The  from  on  and  the The  are  marked  points  scattered  over  coal  are  a  travel at  mines a r e  typically  c o n s i s t e d of  drill  holes  explosive  spaced  delays  gave  typical  multiple Lcrnex  total  blast  zone and  but the  were p r e c i s e l y companies.  spread shots  of  over  of 70  t o 200  more t h a n  the  through  uncertainty  was  of  the  PNT  base o f  d i s t a n c e c a l c u l a t i o n s was  of  the  Lornex Kaiser of  with  Kaiser  and shots  15 t o  20  m  with  impulsive  since  s e c t i o n of E S . one  holes  Some  second. size  centre the  cooperation  associated  sections  are  i n charge The  from  used.  filled  each  delays.  e l e v a t i o n of  the  m grid and  record  pits  The  were s m a l l e r  similar  s  timing  profile  were n o t  detonation  determined  The  i n the  had  100  m apart  time d e l a y s  Bethlehem  extent,  30  the  apart.  by  the  were n o t  while  explosions  the  b l a s t s were  and  5 km  MICA and  a large  various  apart,  a 200  The  between  areal  errors  about  about  slurry.  time  km  The  .02  t o match a r r i v a l s  ends o f  area.  e r r o r of  shot  s r e s p e c t i v e l y , were  with  times  both  t o one  Eethlehem  .4  ability  Traces  Standard  complete  The  a p p r o p r i a t e l y on  small  up  the  s to  of  variable distance  location.  .1  blasts.  arrival  shot  nine  s and  the  timing  the  north  Canadian  1 gives  and  blast  b a s i s of  untimed  first  Table  to t h e  (PNT)  p o i n t system  exact .04  array  Pentictcn  capability  the  the  uncertainty and  the  shot  e r r o r s of  assigned timed  from  reading  gecphcne timing  MICA s e i s m i c  Network s t a t i o n .  statistics. based  the  of  drill  of the  shot  assumed  The and  the holes mining  location to  be  less  Table no  1.  Shot  statistics.  corresponding  Seme of  stations.  The  elevations  were d e t e r m i n e d  from  the  companies.  mining  determined  at the  remotely  and  than  s.  .03  site,  Most but  have e s t i m a t e d  the  locations data  timings  shots  had  and  supplied  by  were  some s h o t s  were  timing errors  timed  greater  SHOT SHOTI  1212-  ' DATE  73 73 70 70  3 - 7U  0- 70 5- 70 6- 7 0 7- 70 8- 7 0 9- 7 0 1 0 - 70 1 1 - 70 1 2 - 70 1 2 - 70-3 1 3 - 70 1- 75 2- 75 3- 75 0-75 5- 7 5 6- 7 5 6- 7 5 - 2 7- 75 8- 7 5 9- 7 5 1 0 - 75 1 1 - 75 1 2 - 75 1 3 - 75 10-75 1 5 - 75 1 6 - 75 1 7 - 75 1 8 - 75 1 9 - 75 2 0 - 75 2 1 - 75 2 2 - 75 2 3 - 75 20-75  s  STATISTICS  MINE-PIT  SIZE'  K AISER-A DIT29  150 09.7525 150 09. 7773 261 09. 7808 230 09. 7582 250 09. 7503 160 09.7607 255 09. 7888 203 09. 7885 067 09.7598 9 50. 0970 03 50. 0583 28 50. 0958 31 50. 0552 100 09. 7905 300 09. 7893 01 50.0962 60 50. 0508 27 50. 0957 300 09. 7878 20 50. 0958 600 0 9 . 7563 220 0 9 . 7 8 37 215 09.7878 19 50. 0537 19 50. 0580 250 09. 7507 27 50.0557 200 09. 7612 10 50.0530 50 0 9 . 7508 OMITTED OMITTED 115 09.7878 7 0 9. 7 6 08  JULY JOLT MAY HAY MAY JUNE JUNE AUG AUG SEPT SEPT SEPT SEPT SEPT  26/73 27/73 21/70 22/70 20/70 6/70 7/70 12/70 13/70 0/70 0/70 5/70 5/70 6/70  B E T H L E H E M - H U E S T is' LORNEX KAISER-HAPMER2  SEPT MAY MAY MAY MAT MAY MAY  6/70 6/75 7/75 8/75 9/75 9/75 27/75  BETHLEHEM-JERSEY LORNEX BETHLEHSM-HUESTIS KATSEP-HAPMER2 BETHLEHEM-HIESTIS KAISER-ADIT29 KAISER-HARHEB2  MAY MAY MAY MAY MAY MAY JUNE JUNE JUNE JUNE JUNE JUNE JUNE JUNE JUNE JUNE JUNE JUNE  27/75 28/75 29/75 29/75 30/75 30/75 17/75 17/75 18/75 19/75 20/75 20/75 25/75 25/75 26/75 27/75 27/75 27/75  LORNEX LCRNEX KAISER-ADIT29 LCRNEX K ATSE R - A D I T 2 9 LCPNEX K A I S E R - 1 6 SEAM LORNEX LOPNEX KAISER-HAPMER2 KAISER LCFNEX BETHLEHEM-HUESTIS  KAISER-HARMER1 K A I S E R - H ARMER2 KAISER-ADIT29 KAISER-ADIT29 KAISER-ADIT29 KAISER-HARMES2 KAISEP-HARMER2 KAISER-ADIT29 BETHLEHSM-HUESTIS LORNEX  LCRNEX LCRNEX BETHLEHEH-IONA KAISER LCRNEX  37  ? 38 17 26 ? 01  LATITUDE  50.  0505  50. 0953 50. 50. 50. 09. 50.  0553 0527 0937 7557 0582  LONGITUDE  110 . 8105  1 1 0 ,. 8 3 0 3 1 1 0 .. 8 3 6 7 1 1 0 .. 8 1 6 5 1 1 0 ,. 8 0 8 3 1 1 0 .. 8 1 7 8 1 1 0 .. 8 3 2 8 1 1 0 ,. 8 3 0 2 1 1 0 .. 8 1 5 0 1 2 0 .. 9 9 0 6 1 2 1 .. 0 0 0 0 1 2 0 .. 9 9 0 9 1 2 1 .. 0 0 6 3 1 1 0 .. 8 1 5 5 1 1 0 .. 8 3 7 7 1 2 0 .. 9 8 2 6 1 2 1 .. 0 0 18 1 2 0 .. 9 9 7 1 1 1 0 .. 8 3 6 2 1 2 0 .. 9 9 8 1 1 1 0 .. 81 5 3 1 1 0 .. 8 3 5 3 1 1 0 .. 8 3 2 2 1 2 1 .. 0 0 0 0 121 , . 0079  1 1 0 .. 8 1 0 8 1 2 1 . ,00 18 1 1 0 .. 8 1 8 3 1 2 1 .. 0 3 9 7 1 1 0 . 8363  110.8322 110.8181 121.0010 120.9903 121.0083 121.0005 120.9787 110.8367 121.0080  KIEV*  TIKE  6370 6370 6370 6270 6220 6220 6370 6295 6220 0000 0672 0333 0752 6 3 20 6320 0967 0632 0267 6320 0267 6170 6270 6270 0672 0752 6170 0632 6120 0672 6150  1 9 : 58 : 0 8 . 9 3 t . 0 2 18:15 : 1 0 . O l t . 0 2 1 8 : 3 3: 0 8 . 6 7 * . 0 2 2 0 : 58 : 0 2 . 9 6 * . 0 2 18:12 : 1 0 . 85*.03 2 1 : 0 3 :03. 2 8 t . 02 1 8 : 38 : 0 8 . 1 3 * . 0 2 18:19 :23.07t.02 2 0 : 5 8 :07. 7 3 t . 0 0 1 9 : 0 2 : 12. 9 0 . 02 2 2 : 50 : 2 8 . 0 8 i . 0 2 19:02 : 32. 9 9 t . 0 0 22:55 : 5 0 . 8 7 * . 0 0  6150 6150 0632 0033  0712 0712 5033 6150 0752  (U.T.)  PNT  t  18: 1 ? : 2 5 . 8 1 1 . 0 0 1 9 : 0 8 : 3 1 . 31±. 0 2 22: 55:55. 2 2 t . 0 0 18:59:50.09*.00 NO TIMING 1 9 : 0 5 : 2 2 . 3 5 * . 02 21:02:18.57*.00 2 0 : 0 1 : 1 3 . 0 2 * . 00  2 2 : 58 : 2 7 . 0 0 * . 0 2 22: 5 7 : 58. 85*. 02 2 1 : 0 1 : 1 7 . 1 0 * . 10 2 2 : 5 3 : 17. 5 2 * . 0 2 2 1 : 0 7 : 0 9 . 5 0 * . 00 22:57:27.05*.02 1 8 : 15:38. 05*. 02  1 8 : 16: 20:59: 22: 5 7 ; 19:06: 22:58: 22:50; 19:29: 20:51: 22:53:  • S I Z E - T H E T C T A L S H O T H E I G H T I N T H O U S A N D S OP P O U N D S * E L E V - T H E E L E V A T I O N OP THE BOTTOM OF T H E SHOT H O L E I N F E E T A B O V E S E A L E V E L » P N T AMP. - T H E P E A K TO P E A K A M P L I T U D E O F T H E P-AEBIVAL M E A S U R E D I N C H . F R O M PNT P A P E R R E C O R D S ( C O R R E C T E D FOR I N S T R U M E N T R E S P O N S E ) •* DENOTES S C A L E AMPLITUDES D E T E R M I N E D FROM M I C A A R R A Y •MULTIPLE BLAST ( T I M I N G G I V E N FOR F I R S T B L A S T )  0. 1 2.  9  2.  9  0.9 0.5 3. 9 5. 6 0. 0 6.5 0. 5 2 0 1. 1 2. 1 5. 3 1.9  6. 0 3. 8 2.  5 1. 0  0. 8 1.6  33.51*.02 5 5 . 9 5 * . 00 06.32*.02 51. 22*. 02 35. 36*. 02 03. 31*. 02  0. 5 1.0 0. 8  5 5 . 5 0 * . 0 2  2.3  02.  5. 8 6. 3 2.5  67*.  00  0.  38. 5 7 ± .  02  8. 8  5  AMP.>  20  than  .1  km.  The  recording sites  outcrops line  found  near  as p o s s i b l e .  closed  circles  shots,  and w i t h  of those  stations  shots. used  number,  stations  errors  generally  less  and t h e y e a r 1:50000  .2 km  Kaiser  which  recorded  2a and 2b g i v e t h e The  of the f i e l d topographic  Forest  with  statistics  identification  i n the c a l c u l a t i o n  than  with the  recorded  shewing t h o s e  Inventory  bedrock  profile  the l i n e ,  which  the system  and P r o v i n c i a l  resulting  to t h e  i n the i n t e r p r e t a t i o n .  were l o c a t e d u s i n g  photographs,  as c l c s e  1 illustrates  Tables  are d e r i v e d frcm  the shct  sites  Figure  roads,  open c i r c l e s  Valley  C),  access  indicating  Highland  labels  were p r e f e r a b l y l o c a t e d on  station (A, B o r  season.  maps,  The  aerial  Maps.  The  o f d i s t a n c e s were  a few e x c e p t i o n s  as  noted  later. The datum  seisnic  stations  were c o r r e c t e d t o an  o f one km a b o v e s e a l e v e l  surface  velocity,  and a 6.0  by a s s u m i n g  o r 8.0  km/s  elevation  a 5.3 km/s  inferred  near-  refractor  velocity. System timing,  system  duplication number  and e n v i r o n m e n t a l malfunction,  resulted  logistical  i n a severe  of recordings a c t u a l l y  Fifteen  of a t o t a l  Valley  recordings.  shots  i n the  and  interpretation.  Kaiser shots  Eighteen were used  prcblems,  poor  r e d u c t i o n i n the t o t a l  used  of nineteen  successful recordings. Highland  noise contamination,  of a t o t a l  were u s e d o f twenty  f c r 41 s u c c e s s f u l  f o r 34  Table  2a.  Kaiser  locations from  station  and e l e v a t i o n s  1:50000  statistics.  were  mainly  t o p o g r a p h i c maps.  determined  The f i r s t  t i m e s were d e t e r m i n e d  from  column  whether t h e t r a c e  PICT i n d i c a t e s  included the  i n the f i n a l  analog t r a v e l  d e l a y t i m e and f i r s t travel  time  erroneous.  picks  section  information  arrival  on n o i s y  arrival  the analog output.  record  time  The  was  and whether  was used  time a n a l y s i s .  traces  The  i n the Many  were c o n s i d e r e d  KAISER  PROFILE  STATISTICS  SITE  LATITUDE  L O N G I T U DE  DISTANCE  TIME*  ELEV*  E-C03'  C137S A77<4 C774 C1675 A474 C674 A674 A1373 A1675 A574 A2375 B774 B1675 C2375 A173 C173 3674 A273 C273 B273 A177a C177j A374 A274 A975 C274 B27U C975 C174 B374 C37U C474 8474 C574  49.77177 49.81351 " 4 9. 814550 19.75793 49.78C17 «9.78i416' U9.e3701 49.73546 a s . 7 C5 en 149 . 7 3 167 < 4 9 . 706U8 49.75334 149. 7 1776  11U. 91401)14 115.13933 1 1 5.214583 115.387C5 115.51666 115.67767 1 1 5 . eo«3u 115.98280 1 1 6 . 223314  7.296 24. 197 32.553 4 0 . 141 50.40 2 6 0 . 80 1 70.115 82.754 100.780 113.664 130.324 135.993 143.877 1 5 0 . 79 1 155. 203 169.653 182.435 196. 176 214.015 23 1. 44 1 234.578 245.326 252.071 26 5. 40 9 2 7 3 . 94 3 279.297  1.62 4. 32 5.65 . 6.99 8. 62 10. 33 11.88 13.00 17. 09 18.88 0.0 22. 82 24. 39 0. 0 26. 07 28.72 30.44 32. 34 3 4.64 36.54 0. 0 0. 0 39.47 40.99 4 1.. 9 1 CO 44. 24 0.0 46.73 50. 83 54. 93 57.67 5 9 . 90 6 4 . 00  4050 4000 4400 5100 5100 2900 2950 5500 5600 3800 4900 5900 3700 1900 6262 3750 2900 2450 2100 2950 1700 3950 3150 4100 2700 1950 2300 2300 5050 3200 3150 2900 4200 4050  -.11 -.11 -.13 -.15 -.15 -.08 -.08 -.16 -.16 -.11 -.14 -.17 -.10 -.05 -.19 -.11 -.12 -.10 -.09 -.12 -.06 -.16 -.13 -.17 -.10 -.07 -.09 -.09 -.22 -.13 -.13 -.11 -.17 -.17  116. 110568  .1 1 6 . 6 2 2 7 7 116.70000 1 1 6 . 823 e« 14 9 . 76146 3 1 1 6 . 9 0 9 7 4 < 4 9 . 9 38 17 1 1 6 . 9 4 7 3 3 50.C4C08 1 1 7 . 127143 49.98734 117.35201 50.12106 117.50882 50.12300 1 1 7 . 761314 50.11633 1 1 8 . C0917 119.90125 118.08612 49.93036 118.23UI47 H9.61551 I 1 8 . 3014 3 14 50.09175 118.U733U 5 0 . 191400 II 8 . 568214 50.2U150 118.63628 5C.26500 118.822e3 50.26500 118.e22 e3 50.35468 119.09801 5C.35C01 119.51666 50.33968 119.95982 50.38100 120.30133 50.148927 120.47021 50.D7569 120.95039  292.e66 293.164 311.637 343.997 375.023 398.842 412.502 4 4 2 . 742  LO-CUT* 0.75 0.75 0.75 0. 75 0. 75 0.75 0. 75 0. 75 1. 50 0.75 0. 80 0.75 0. 75 0. 80 0. 75 0. 75 0. 75 0.75 0. 75 0. 80 0.80 0. 75 0.75 0. 75 0. 80 0.75 0. 75 0.80 0. 75 0. 75 0.75 0.75 0.75 0.75  HI-CUT  PLOT*  12.50 Y Y 12. 50 Y Y 12.50 t Y 12. 50 Y Y 12.50 ' Y Y 12.50 Y Y 7.00 Y Y 7.00 1 Y 6.00 I I 10.00 Y Y 8.00 Y N 12.50 Y Y 6.00 Y Y 8.00 N N 8.50 Y Y 12. 50 Y Y 8.00 Y Y 12.50 Y Y 7.50 Y Y 7.00 Y Y 7. 50 Y N 7. 50 Y N 6.00 Y Y 6.00 Y Y 8.00 Y Y '6.00 Y N 6.00 Y Y 6.00 N N 7. 50 Y Y 5.20 Y Y 7.50 Y Y 5.00 Y N 5.00 Y N 5.00 Y N  :  TTIDLE  SCIDLl  - . 15 - . 10 -.18 0.0 0.0 0.0 0.0 0.0 0.0 -.30 0.70 0.0 • 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0  1.00 1. 00 1. 00 0.50 1. 00 1. 00 1.00 1.00 0. 50 1.00 1. 00 1. 00 1.00 1. 00 1. 00 10. 00 1.00 1. 00 10. 00 1.00 0. 25 0. 25 1.00 1. 00 0. 25 1.00 1. 00 1.00 2. 00 1. 00 1.00 1. 00 1. 00 1.00  ' T R A V E L T I N E I K SECONDS I S DETERMINED EROH ANALOG P L A Y B A C K S A Z E d C I M P L I E S THAT NC T I M E CCULD E E DETERMINED ^ E L E V A T I O N CP T H E RECORDING S I T E IN F E E T ABOVE SEA L E V E L (FROM 1:50000 BAPS) E L E V A T I C N C C R R E C I I O N I!l SECCNDS TO A CNE K K DATUt! ( A P P L I E D T C ELOTS FOR D I S T A N C E S OVER 80 KB) THE C C R R E C T I C K I S SOT INCLUDED IN THE T R A V E L T I M E S REPORTED I N T H I S T A B L E •LO-CUT AND H I - C U T ARE T H E L I M I T S IN HERTZ CF THE BANDPASS F I L T E R USED CN T H E F I L T E R E D BECOBO S E C T I O N S *THE F I R S T COLOMN CF E L C T S P E C I F I E S WHETHER OR NOT (Y OR N) I HE T R A C E I S INCLUDED I N T H E F I N A L S E C T I O N T H E S I C C N D COLUMN S I M I L A R L Y S F E C I F I E S I F THE ANALOG TRAVEL T I M E INFORMATION HAS USED J  Table The  2b.  Highland  locations  determined first analog  output.  the  trace  and  whether  useful.  wsre  statistics.  mainly  1:50000 t o p o g r a p h i c maps.  times  were d e t e r m i n e d  The column  was i n c l u d e d the analog  Many  station  and e l e v a t i o n s  from  arrival  Valley  travel  travel  were c o n s i d e r e d e r r o n e o u s .  from t h e  PLOT i n d i c a t e s  i n the f i n a l  time  The  time  picks  whether  record  section  i n f o r m a t i o n was  cn n c i s y  traces  HIGHLAND SITS  .  LATITUDE  A87tt A 97 4 C874 C974 8874 B974  LONGITUDE  50. 47569 50. 47569 50.4P560 50. 4 8 5 6 0 50. 47029 50. 47029 50.48151 50. 48151 50.46567 50.45667 50. 45000 50. 45000 50.43805 5 0 . 38 100 50. 34550 50. 34550 50.32458 5 0 . 33 968 50.3«452 50. 42976 .50. 35739 50.38300 5 0 . 3U575 50. 34575 5 0 . 34354 50. 35309 50.26500 50.1"H00 50.06657 4 9 . 93036 4 9.93036  A1074 A 1174 C1074 C U 74 B1074 B 11 71* A 1374 C1374 A275 A175 B1275 C275 C1275 A 12 75 BU75 C475 A775 B875 C875 A875 C1075 A 1075 B21 75 C1375 A 21 75 A 1875 C2175 A 1 9 7S A 20 75 C1975 C2075 B2075 C2275 A 2 2.75 A 24 75  120.95042 120.95042 120.88460 120.88460 120.81161 120.81161 120.73000 120.73000 120.64999 1 2 0 . 64999.^ 120.53333 120.53333 120. 39127 1 2 0 . 301 33 120.28320 120.28320 119.99663 119.95982 1 1 9. 3 2 5 8 5 119.62^29 119.51070 119.34067 119.20061 119.20061 119.11406 118.92316 118.82283 118.56824 .1 1 8. 435 33 113.23447 1 1 8. 2 3 4 4 7 118.08612 1 1 8 . 086 12 117.79668 117.79658 117.53307 117.53307 117.34902 116.90974 116.62277 116.62277  49. 90125 49.90125 50. 06081 50. 06081 50. 13155 50. 13155 4 9 . 98? 33 49. 76463 4 9 . 70648 49. 70648  DISTANCE 4. 399 7 . 296 3. 519 12. 0 4 8 1 3 . 560 16. 896 19. 050 2 2 . 860 24. 8 8 7 2 8 . 34 1 33. 287 36.610 4 2 . 540 5 0 . 161 5 3 . 521 5 5 . 387 75. 627 75.882 86.603 100.467 106.953 1 1 8 . 520 131.433 132. 039 138. 199 151.591 159. 463 178.697 1 9 1 . 102 2 0 8 . 923 209.073 2 2 0 . 069 220.222 2 3 3 . 191 2 3 6 . 182 250.057 25 3. 278 269.400 302.260 323.958 3 2 7 . 850  VALLEY TIHE  PROFILE  0. 70 1.07 1. 42 2. 07 2.53 3. 11 3. 29 3.86 4. 39 4. 90 5.62 6. 10 7.23 8. 64 9. 64 ' 9.88 12.60 12.71 0. 0 1 6 . 45 1 7. 85 19.65 22. 26 2 2 . 35 2 3 . 30 2 5 . 00 2 6 . 07 2 8 . 78 0. 0 32. 58 32. 84 3 4 . 07 34. 32 0. 0 3 8 . 69 0.0 4 0 . 24 0. 0 0. 0 4 7 . 01 0. 0  STATISTICS  EL LE EV V ** E  1  '  E -- C E CO OR R» *  4050 -.06 4050 -.07 3900 . -.05 3900 -.06 3300 . -.04 3300 -.04 3850 -.05 3850 -.06 4000 -.06 4000 -.07 4500 -.07 4500 -.08 3600 -.06 3100 -.05 3800 -.05 3800 -.06 3350 -.05 3150 . - . 0 3 2300 -.01 3400 -.05 3200 -.03 2050 0.01 3200 -.04 3200 -.04 4500 -.08 2500 -.02 2300 -.01 2700 -.02 4200 -.10 3950 -.09 3950 -.09 1700 0.01 1700 0.01 2500 -.02 2500 -.03 2450 -.01 2450 -.03 2900 -.05 1900 - . 02 4900 - . 15 4900 - . 14  LO-COT* 0.75 0. 75 0. 75 0. 75 0. 75 0. 75 0. 75 0. 75 0. 75 0. 75 0. 75 0. 75 0. 75 0. 75 0. 75 0. 75 0. 75 0. 75 0. 75 1. 00 0. 75 0. 75 0. 75 0. 75 2. 70 2.70 0. 75 0. 75 1. 00 0. 75 0. 75 0.75 0. 75 1. 50 0. 75 1. 50 0. 75 0. 80 1. 50 1. 00 1. 00  HI-CUT 12. 50 12.50 12. 50 12. 50 12. 50 12. 50 12. 50 12.50 12. 50 12. 50 12. 50 12. 50 12. 50 12. 50 12. 50 12. 50 12. 50 .12.50 5. 20 12.00 5.50 9. 50 10. 60 10.60 10.00 10.00 10. 00 12. 50 5. 50 12.00 12.00 5. 5 0 5. 50 4.00 12.00 4.00 5.50 5. 50 5.00  PLOT*  TTIDLE  I Y I Y Y Y Y Y Y Y  0.0 -.20 0.05 - . 22 0 0 0  1 Y Y Y Y Y N Y Y Y Y Y Y Y Y Y Y Y Y N Y N Y  Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y N Y Y Y Y  05 0  Y . Y Y Y Y N N Y N Y  5. 50 6. 00  -.05 -.05 0. 92 0.05 -.02 0 . 10 0.0 0.0 -.08 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 . 10 0.0 0.0 0.0 0.0 0.0 0.0 . 0.0 0.0 0.0 0.0 0.0 0.0  • T R A V E L T I K E I N S E C O N D S IS D E T E R M I N E D F R O H A N A L O G P L A Y B A C K S A Z E R O I M P L I E S T H A T NO T I K E C O U L D B E D E T E R M I N E D  ^ M ^  0  5  1  °  ™  F  S  R  S  C  0  *  D  I  !  ,  G  SITE  I N FEET  ABOVE  SEA LEVEL  lll lr\ll°" ™ S E C O N D S TO A O N E K M D A T U H T R E C O R R E C T I O N I S NOT I N C L U D E D T N T H E T R A V E L T I M E S Z  C  0  P  R  C  T  I  0  N  (FPOM  1-50000  MAPS)  ( A P P L I E D TO P L O T S FOR D I S T A N C E S REPORTED I N T 5 K T»BL»  OV-R  80  K  H  l '  SCIDLE 1. 1. 1. 1. 1. 0. 1. 1. 1. 1. 1. 1.  00 00 00 00 00 25 00 00 00 00 00 00  1. 00 1. 00 1. 00 1. 00 1. 00 1. 00 0. 50 0. 50 1. 00 1. 00 1. 00 1. 00 1. 00 1. 00 ' 1. 00 1. 00 1.00 1.00 1.00 1. 00 1. 00 1. 00 1. 00 1. 00 1. 00 1. 00 1. 00 1. 00 1. 0 0  25  2.  Pjelijinari  The  FM  field  subsequently time)  to a  with magnetic  Hewlett Corp.  t a p e s were e d i t e d  digitized.  were i n p u t  system  tape  Analysis  P a c k a r d FM  AN5800  A-D  transport  tape o u t p u t .  playback u n i t ,  digitization  was  sample r a t e  fluttering  was  and  used  not  e x a c t , and  final  determined  as TTIDLE  was  and  used.  digital  The  9-track  digital  formatter,  and  effective  from t h e f i r s t average  24  An  seconds  digitizing  included  I t was  by  determined  due  of data  rate  was  of the  i n Table 2  matching  i t s effect  to  average  the a p p e a r a n c e  t i m e s and  a  Analogic  a time c o r r e c t i o n  arrival  plus  included  tape s t r e t c h i n g .  The  and  ccnvertor  w i t h minor v a r i a t i o n s  i n o r d e r t o improve  action,  8108  8230 b u f f e r e d  Hz  and  i n the a n a l y s i s .  record  analog  62.5  system  a modified  circuits.  tape  (three seismic  The  a Kennedy  w i t h a Kennedy logic  tape speed  a master  14 b i t a n a l o g - t o - d i g i t a l  contrcl-interface  FM  Four c h a n n e l s  convertor,  rate  onto  is  the primarily  aesthet i c . Power s p e c t r a l autocorrelation seismic 4 Hz.  was  the m a j o r i t y  considerable  b a n d , however, so t h a t break,  cnly  traces  passed.  For  cutoffs  o f .75  using  a  truncated  power e s t i m a t e , showed  e n e r g y , on There  analysis,  that  unfiltered and  12.5  that  of traces,  signal  Hz  field  a t t h e -6  dB  between  of t h i s  guality  showed s i g n i f i a n t the  was  outside  t o p r e s e r v e the  traces  most o f t h e  of the  noise system  level  were  2 and  pass first band  amplifier  are guoted i n  26  Table  2.  The  digital  the n o i s e spectrum preceding  the  Butterworth the  the  determined  first  filter  from  arrival.  were s e t t o  the  A fourth  (Kanasewich,  some c a s e s c r o s s - t a l k  seismic channels  within (MEM)  the frequency spectral  closely  1975)  five  seconds  crder was  eliminate of  noise  zero-phase  used  tc  bandpass  filter  ratio  was  not  width  o f a few Amplitude  amplifier  and  The  by  azimuths  was  would  applied  profile  No  the  However, b e c a u s e  inoperable  f o r a s h o r t time from  in  charge  Although  were n e t u s e d  a  arrivals  system field  was  arrival  on  PNT  the close  estimate  could give was  work, some o f ;  as  were i n c l u d e d directly  the  t o be  station  field  estimated  but  station  FNT  gain  also  the amplitude  the  to  bandpass w i t h a  MICA a r r a y a r r i v a l s sizes  the  were j u d g e d  during the  t h e s h o t s were s c a l e d  they  and  profile,  e t h e r permanent  used  signal-to-noise  the  first  that  was  -  traces.  blasts  of the  Entropy  i n order that  to the  from  c f the  direction  data.  comparison,  due  shot s i t e s  equivalent  1.  filter  to these  factors  i s south  to the  be r e a s o n a b l e . ,  Table  notch  yield-of  This s t a t i o n  enough t o t h e  spectra  However, t h e  were c a l c u l a t e d  energy  relative  Maximum  Bishop,1975)  signal  the  determining the amplitude  records.  and  applied.  correction  responses  settings.  (Dlrych  signal.  a c o m p r o m i s e , a narrow  Hertz  and  of the  be  As  channels  limits  improved  were d i s t o r t e d .  the time  considerable noise contamination  the n c i s e  might  between  caused  analysis  resolve  notch  fcr  limits  traces. In  by  filter  indicated i n Table  i n the  1  scaling.  27  but  they  d i d help i n d i c a t e  The  scale  tc  correct  to  allow  adjustment  less  factor  f o r i n a p p r o p r i a t e shot  smoothly  independent of  difficulties.  shots  of  by  scaling,  along  the  the s h o t .  9-75,  corrected  SCIDLE i n T a b l e  possible errors in field  assumed t h a t , a f t e r or  some  12-75, the  amplifier  yield  the  profile, Using  16-75  additional  gualitatively  justifiable  TTIDLE f a c t o r  i n that t h e i r  and  this  and  factor  vary  more  should  be  recordings  amplitude  SCIDLE. are  and  was  should  criterion,  adjustments effect  It  t h a t they  17-1/5 were  used  settings,  factors.  amplitudes  2 was  These similar  to  the  i s more a e s t h e t i c t h a n  substantial. The final  t r a c e s were d i g i t a l l y  filtered  Question timing  tics  f o r the  on  picked  from  records  t r a c e was  the  only  trace label  approximate,  to the  the  FM  seven  channel  were g e n e r a l l y e a s i e r Only  plotted;  the 2 and  the full  into  s e t of data full  was  the  source  t r a c e s i n Highland  to the  body  Valley,  In o r d e r t o e n h a n c e t h e waves, an  R  2  arrival The the  times  as  analcg digital  clear  were 2. and  enlargement with head  geometrical  the  horizontal  included i n Table  F i g u r e H i s an  4.  the  only  record sections cf Kaiser  shots, while  relative  first  t c p i c k than  Valley  velocity.  small  the  3 and  that  so t h a t  p i c k s w h i c h were r e a s o n a b l y  3 are  reducing  imply  playbacks.  Highland near  The  t r a c e s correspond  tracks.  Figures  after  information i s relevant.  the  compiled  r e c o r d s e c t i o n s , shown i n F i g u r e s 2,  marks p l a c e d  amplitude  e d i t e d and  a  6  km/s  waves  spreading  of  factor  was  included  i n the  apparently  unreasonable  corrected,  are  interpretation. information structure  was  mentioned The  as  they  remaining  appear  amplitude  be r e l a t e d  profiles.  A  scaling.  descrepancies, that  assumed t o  a l c n g the  amplitude  cculd  few not  be  i n the and  travel  tc geophysical  time  Figure  2.  Kaiser  traces  are  factor  applied  amplitude  distances.  The  output.  Question  only  corrected  The  and  filtered  have a at  arrival  that  picks  from  marks a p p e a r i n g those  amplitude  traces  had  the  information.  2  the  traces  analog  beside poor  R  large  h o r i z o n t a l t i c marks on  first  names i m p l y  section.  t c emphasize a r r i v a l s  mark t h e  provide  record  trace  timing  and  DISTANCE  (KM)  Figure  3.  filtered R  2  Highland traces  factor  are  applied  distances.  The  first  output.  Question  provide  only  record  amplitude  section.  corrected  emphasize  arrival  that  picks  arrivals  from  marks a p p e a r i n g those  amplitude  traces  had  the  at  information.  have a large  the  traces  analog  beside poor  The  and  h o r i z o n t a l t i c marks on  mark t h e  names i m p l y  to  Valley  trace  timing  and  00  DISTANCE  (KM)  Figure The  4.  Near s o u r c e H i g h l a n d  first  seventeen traces  displayed filtered R  2  with traces  a reducing are  factor applied  distances. mark t h e output.  The  first  of  Valley  Figure  v e l o c i t y of  1  are 6 km/s.  amplitude corrected  and  to emphasize a r r i v a l s  h o r i z o n t a l t i c marks on arrival  picks  from the  section.  at  The have a  large  the  analog  traces  CM  H I G H L A N D  VALLEY  DISTANCE (KM)  35  CHAPTER  1.  Frj5liminar_y I n t j r _ c r e t a t i o n  Several tc  III  factors  encouraged  the i n t e r p r e t a t i o n .  discontinuities  with  More s o p h i s t i c a t e d structures very  The p r o f i l e has o b v i o u s  few e t h e r  non-impulsive frequency  few  kilometers  geophysical  approaches t o s e i s m i c  are not r e a d i l y  lew  a r e l a t i v e l y simple  nature  available.  at depths  discontinuity.  Timing  unidentified  and u n c e r t a i n  and r a p i d l y  much c f t h e d a t a difficulties, suggested  changing  by t h i s  to a  site  inclement  ether  location  i n poorly  areas a l l contributed  features  t c make  Despite  these  are defined  or  experiment.  Common a s s u m p t i o n s the  interpretations.  7.5  km/s  critical  a r r i v a l s from  interesting  with the  t o t h e H-  of i n d i f f e r e n t q u a l i t y .  several  together  malfunctions,  seismic  mapped  of these  l i m i t s the r e s o l u t i o n  weather, i n t e r f e r i n g blasts,  constraints.  In any e v e n t , t h e  corresponding  equipment  lateral  modelling  o f the sources,  of the r e c o r d i n g s ,  approach  cr greater refractions  about  Arrivals  observed with  were i n t e r p r e t e d from  a r r i v a l s were u s e d i n  an a p p a r e n t  velocity of  kinematically  the M - d i s c o n t i n u i t y .  as  Amplitude  36  modelling of  these  (Eraile  r e q u i r e d the waves a s  and  apparent  grcup  behaving  of a r r i v a l s  1975).  i n the  these  was  travel  suggested  with  basic  frcm  described  by  e s t i m a t e s of  York the  km,  and  Exceptions are The  may  be  of m u l t i p l e Forsyth,  cnly  7.0  to  second  and  fits  7.4  The  depths  to the  cf first  errors  first  by  Ahem  usual error  Valley  of  times  in Figure 5 the  generalized  (1975) f r o m  time  detailed be  program  a s s o c i a t e d with distance  normally  discussion fitted  a  from  a s s i g n e d t o the was  along  near-surface  were computed  timing error  data can  arrivals  arrival  plotted  i n d i s t a n c e and  i n the  t c the  u s i n g a weighted  Weights  t h e assumed  Highland  The  a cross-section  (1969).  noted  fits  identified  r e c o r d s are  adapted  The  line  and  were f i t t e d  program  observation. .2  squares  straight  and  lines  sguares  they  from  velocities  be  critically  ( B e r r y and  although  to  Kaiser record section.  difficulties.  the analog  The  sum  velocities  least  structure  the topography  least  was  made from  models from  the  geology.  on t h e  and  Dynamically  t c the  identified,  with  times.  interpretational picked  with  waves  were assumed  wave g u i d e  d e t e r m i n a t i o n of the  Simple  each  layers  were o b s e r v e d  layers  arrival  crust.  head  Phases  sub-critically  upper  crustal  were t e n t a t i v e l y  preliminary  km/s  corresponding  Intermediate  arrivals  1966).  t o 6.1  like  dynamic r e p r e s e n t a t i o n  or d i f f r a c t i o n  Cerveny,  c f 4.5  waves i n t h e  reflections  km/s  1975;  velocities  refracted a  interference  Smith,  kinematically  more c o r r e c t  .05  s.  below.  reasonably  with  Figure  5.  T r a v e l times, topography,  U p p e r : Reduced t r a v e l from  least-sguarss  Highland from  Valley  Kaiser  fits  profile  were measured  VolcanicsSediments  on  Crosses are data  Campbell  along  (1973) and  cross-section Wheeler  (1 972) . ^ WM and  Volcanic  SedimentsHudsonian  Basement-EES  Paleozoic  Sediments-  the  1:250000 maps,  schematic g e o l o g i c a l  Intrusives-  determined  squares are  topographic variations  from  Gabrielse  t o t h e data<  geology.  shots.  The  adapted  c u r v e s were  o b s e r v a t i o n s and  Middle:  l o w e r : The  time  and  Sediments-lys-al  and  was  38  CD V= 7 . 9 3 ± . 0 4 km/s  CD  •  Tj=7.38±.2s  —Q-  •  •  •  •  V= 7.49+.01 km/s Tj = 4 . 9 3 ± . 0 4  '  Tj =V= 4.42±.03s 7.3 6 ±.01 km/s  CO  \  \E  V=6.11±.03 km/s  LO  Tj = .39±.03s  co  CD  CO  V=6.04±.04km/s Tj= .121.05 s  C\J  |+  180 270  90 360  0 450  DISTRNCE (KM)  INTERIOR  PLATEAUX  EASTERN  I fif ? / ' / - ^ ^ ^ ^ JOkn  4 0 km  METAMORPHIC  360 90  270 180  BELT  T,  0  PURCELl RMT ROCKY +. ANTICLINORIUM I I MOUNTAINS I  £'*  '~*^~\  39  a two  layer  travel  time  difference 178  model, a l t h o u g h  km  branches  previous  i s displayed  i s i n the  represent  assumption  a separate  points.  The  i s non-zero,  systematic  scatter  The  has  a least  two  layer  km/s.  The  half-space) with  an  gives  a  intercept  apparent would this  With  be  interpreted  If as  7.6  the  a separate  2 3 . 4 ± 1 . 0 km  This  can  below  be  has  an  interpreted associating  over  Pn  arrivals.  Kaiser  velocity km  of  the  of  as  in  shot  have l e s s  on  upper  The  for  arrival  km  30  s c a t t e r , the  with  km, of  are and  layer  7.49±.02  branch,  v e l o c i t i e s of  Because the  the  6.1+.5 km.  mantle  first  a  km/s  velocities  of  two  and  a profile  178  the  6.G4±.04  layered  a 7 . 3 6 ± . 0 2 km/s  c u r v e has 5.  Pn  v e l o c i t y of  apparent  Figure  6.11±.03 km/s.  an  a  km  depth of  a thickness  apparent  t r a v e l time  branches p l o t t e d  14.6±1.4  a r r i v a l s past  with  of  The  of  5 give  below.  7.35±.05  horizontally  five  crustal  layer  ft  branch, then  the  v e l o c i t y of  arrival  past  the  i s discussed  apparent  first  i n Figure  criterion with  a  three  a  half-space  and  from  of  one  three  pcints  surface  v e l o c i t y of  a depth  as  plotted  of  near  (actually  layer  km/s  intercepts depth  that  4.41±.12 s .  observed  length.  three  this velocity structure,  velocity  not  the  with The  branch  apparent  assumption  of  the  5.  this i s a vestige  squares  model c a l c u l a t i o n y i e l d s interface.  of  points  lower  version  in Figure  t r a v e l time  but  i n the  layer  that  intercept  refraction  branch  a three  well has  six  an  7.5  The km/s.  using km/s  the or  defined apparent  points  intercept,  at  within  ,39±.03  70 s.  ao  was  calculated  recording layer  using  site  clcsest  of  33.2±1.1  km  of  35  about It  them.  1.3±.1  km.  putting  The  to the shot  o f a . 5 ± . 0 2 km/s  velocity  thickness  cnly  The  arrival  implies  at the  an a v e r a g e  w i t h a maximum p r o b a b l e  second  layer  t h e 7.93±.04 km/s  has a t h i c k n e s s  half-space  there  changes  a l o n g the  a simple  layered  model i s i n a d e q u a t e .  dipping  layer an  model was  about  under  average  computed  25  discussion  the  the  that The  are  simplest  considerable horizontally  alternative  is a  crustal  dipping  velocity velocity  2° t o t h e  Highland V a l l e y  shot point.  of the t r a v e l velocity three  t o be g r e a t e r  Based  c f 6.1 o f 7.7  east  , a  km/s,  and  from  to a depth on  km/s  c f 37  be t o o low,  layer  model,  t h a n t h e one  km  the p r e v i o u s  time c u r v e s , the assumption may  crustal  models d e r i v e d  f o r the  particularly fcr  so t h a t  calculated  v e r y vague a v e r a g e s . arrivals  and  identified  using  programs.  A delay  separate upper  upper  later  the depth i s  at that  and  time approach topography  velocity.  the f i r s t  extend the  phases  ray t r a c i n g  mantle  crustal  To  from  end  of  The  synthetic  from  arrival  data  interpretation,  cn t h e r e c o r d  was  a  a depth  profile.  second  the  and  with a mantle  under  crustal  The are  km  upper  Highland Valley  likely  depth  U s i n g f o r m u l a e f r c m D c b r i n (1 960) , and  gently  the Kaiser  average  profile,  model.  M-disccntinuity of  at a  of  km.  i s immediately obvious that  assuming  first  section  were  seismogram  finally lateral  considerable  used  to  variations in near-source  41  variations in  detail  2.  frcm  i n the f o l l o w i n g  Near S o u r c e  The shot  the Highland  an a t t e m p t  geology.  profile  The a v e r a g i n g n a t u r e  necessarily  phase.  Figure 6  o u t t o 80 km w i t h a 6.04  of lower  are sharp Bethlehem  velocity  with f o u r arrivals  squares  range.  The more r a p i d  Bethlehem  arrivals  overcompensation scaling. Rayleigh  may  waves  sharp  displays  blasts  (ground  i n t e r c e p t of  cycles  i n the  first  first  a r e i n t h e 3 t o 7 Hz  amplitudes generate  frequency  slight  f r c m t h e PNT much  larger  The s u r f a c e wave a r r i v a l s a r e  (C1174, A1374) b u t t h e y  i n Figure  surficial  The n e a r - s o u r c e  an a p p a r e n t  also  roll).  travel  t o have h i g h e r f r e q u e n c i e s  arrivals  explain  makes  km/s  a t t e n u a t i o n of the higher  between t r a c e s , r e s u l t i n g  The  or f i v e  o f Bethlehem  The L o r n e x  rocks.  tend  3 t o 10 Hz w h i l e L c r n e x  branch  of a  of the geology  qualitative.  The l e a s t  Valley  s c a n be b e s t e x p l a i n e d a s due t o v a r y i n g  arrivals  often  Valley  to get s e i s m i c i n f o r m a t i o n  and t h e c o m p l e x i t y  scurce traces  thicknesses  and  sections.  near  curve p l o t t e d .  . 12±.05  are described  concentration of s i t e s  the e v a l u a t i o n  time  curves  Highland  the l o c a l  near  time  from  refraction  the  travel  Crusta 1 P r o f i l e  points r e f l e c t s  about  of  the c r u s t a l  were n o t w e l l  correlated  i n t h e p o o r l y d e f i n e d 3.4  km/s  6.  traces are paired.  AS74 were r e c o r d e d from  F o r example the Bethlehem  , t h e r e c o r d s A874 and L c r n e x  shot  Figure  6.  Near s o u r c e  with t r a v e l  time curves.  curve i s a near 3.4  km/s  primarily 1 0 - 7 4 , and 74,  produced  13-74, and  first  by  wave  Lornex  6.04  (ground  blasts.  were L o r n e x  km/s The  arrivals  shcts.  roll)  Shots  were B e t h l e h e m s h o t s and 1-75  section  refraction.  the second  to the s u r f a c e  2-75  The  source c r u s t a l  curve through  corresponds  Highland Valley  8-74  9-74,  1  an  points respectively,  u s i n g t h e same s i t e .  The r a y p a t h s a r e  s i m i l a r near the r e c e i v e r , but they a r e very d i f f e r e n t to  the shot p c i n t s .  between f i r s t  Therefore, t h e apparent  arrivals  within  The if  independent  apparent v e l o c i t i e s  of the l o c a l  and i s  geology of the s i t e .  between a d j a c e n t s t a t i o n  t h e y a r e c o n s i s t e n t f o r Lornex and Bethlehem  separately, reflect  f r o m two  t o the geology  a few k i l o m e t e r s o f t h e s h o t p o i n t s ,  relatively  velocity  d e t e c t e d a t t h e same s i t e  s e p a r a t e s h o t s i s assumed t o t e r e l a t e d  lateral variations  p r o p e r t i e s between t h e s i t e s .  close  locations, shots  i n acoustic  U s i n g t h e above  assumptions,  r e a s o n a b l e e x p l a n a t i o n s c a n be f o u n d f o r most o f t h e observed t r a v e l time The  anomalies.  d e v i a t i o n s frcm the l e a s t - s q u a r e s t r a v e l  along t h e near source p r o f i l e  are small,  c o n s i s t e n t , t h e n some g e o l o g i c a l f e a t u r e w i t h them.  The a v e r a g e  A874 a n d t h e B e t h l e h e m velocity Eethlehem the  velocity  time  but i f they a r e may be c o r r e l a t e d  between t h e f i r s t  site,  mine i s 6.2±.2 km/s w h i l e t h e a v e r a g e  f r o m A974 t o t h e L o r n e x p i t i s 6.7±.2 km/s. mine i s on t h e e a s t s i d e  G u i c h c n Creek  curve  Batholith  of t h e Bethlehem  (Northccte,1969).  The  Phase o f  The L o r n e x  mine i s on t h e w e s t e r n m a r g i n , s o t h a t t h e r a y p a t h s o f t h e waves t r a v e l l i n g the  batholith,  avoid the  it.  rest  from L o r n e x  b l a s t s go t h r o u g h t h i s  w h i l e t h e r a y p a t h s from Bethlehem  The two r a y p a t h s a r e s i m i l a r  t h e Bethlehem  Phase  shots  t o each o t h e r f o r  of t h e i r course i n the Highland Valley  implies that  phase o f  Phase.  n e a r t h e c e r e zone  This  of t h e ,  45  batholith  has an a v e r a g e  surrounding km/s,  t h e average  crust. with the  this  stations small  data zone  Phase has a v e l o c i t y  f o r the I n t e r i o r  (Ager  farther  Plateaux  away  from  i n the apparent arrivals  azimuths.  f a r as 55 km  from  arrivals  a t t h e same  and s u g g e s t  that  to the t r a v e l  thickness  relative  The Nicola  low v e l o c i t y  outcrop,  stations  6.0  km/s.  have d e l a y e d from  exaggerating The  c a n be  Phase observed  "Hybrid"  time  curve,  a t B874 and perhaps  zone a t t h e o u t e r was a c t u a l l y  margin o f  o f f of the  s e d i m e n t s o f unknown  the a r r i v a l .  A1074 t o B1174 a r e l o c a t e d cn t h e The s c a t t e r e d a r r i v a l with  thicknesses of g l a c i a l  a t C1074 and C1174 a p p e a r  the apparent  arrivals  Different  most o f t h e c u t e r  an i n h o m o g e n e o u s z o n e ,  Unknown  make t h e a r r i v a l s  sites.  The t i m e s  on u n c o n s o l i d a t e d  Group o f v o l c a n i c s .  appear t o r e f l e c t near  6.0 km/s.  However, t h e s i t e  t h a t may  between  This c h a r a c t e r i s t i c  B974 a r e l a t e  bathclithic  azimuths of  a r e i n t h e Bethlehem  near  bathclith.  toward  locations result i n  velocities  p h a s e s have v e l o c i t i e s  the  seem t o c o n f l i c t  C874 and C974 were i n t h e o u t e r  by a l a t e r a l  6.1  the sources.  zone o f t h e b a t h o l i t h  caused  near  near-surface  The c h a n g i n g  the shot  of Lornex r a y paths  different  The  et al.,1973).  and L o r n e x  proportions  while the  s i n c e the d e n s i t y g e n e r a l l y decreases  variations  Bethlehem  as  Valley  Gravity s t u d i e s of the b a t h c l i t h  core  for  Highland  o f 6.7 km/s,  velocity  magnitude o f the  a t A1374 and C275 s u g g e s t  times  velocities drift  late,  miqht  thus  inhomcgeneity. that,  although  46  the  formations  a v e r a g e 6.0 arrival  km/s  the  s late.  acoustic  qualities  explanation to  location km  on  inadequate  of  correlate  energy  with A175  the  traces.  in its  displayed Figure high  10  confirm km.  is early.  crustal  an  East  average 120  km,  -.5  s on  to  distances  (page  This  59).  i s a very  l a r g e amplitude The  crustal the  attenuated,  since  B875 a r e  late.  may  This  velocity  crustal  severely  be  next  phase  the due  and  the  to This source apparent  observed  t h a n 80  arrival  at  arrivals,  6.04  km/s  and  a major  lateral  low  C475,  out  at  km  with  to  i s e i t h e r delayed arrivals  on  A1275  unusual t r a c e  t r a c e s , E475 and of  3  sguares  shots.  only  The  due  exact  least  greater  later  observed to  to the  unidentified  are  to  reasonable  appears  V a l l e y shots,  at  phase.  an  due  are  However,  i n the  A175  A175  were a s s i g n e d  c l o s e r to t h e  due  reflect  presumably  i s no  traces  s i n c e they  10  i t may  delay.  accordingly  traces  arrivals  frequency  amplitude  cn  in Figure  f o r the  late  A275 and  there  the  unconsolidated'  i s some d o u b t as  at  erroneous  crustal  but  that these  Highland  are  are  so  i s probably  coorelaticns  The  grounds  at  The  " r i n g y , " probably  site,  arrival  r e l a t e d to the  arrivals  very  were w e i g h t e d An  noisiest  the  site,  calculations.  net  The  are  l o c a t e d , or  N i c o l a Group,  mapping, t h e r e  of the  on  was  i n the  seismic  e r r o r s and  arrival  site  traces  inhomogeneous,  a t t r i b u t e d to the  detritus.  The  very  i s well determined.  be  which the  inhomcgeneity  underlying .6  velocity  a t C1374 c o u l d  s e d i m e n t s cn further  between them a r e  120  or  A775  and  47  geological which  3•  boundary  i s located  Near S o u r c e  The  profile  of  Highland  crustal km.  125  at about  presents  Although  they  structures  are  Plateaux.  Also,  expression,  the  from  less  that  Kaiser  There  arrivals  very  over  have  at  least  complex, the  density,  than  the that  the  upper  first  80  geological  those  a more o b v i o u s  i s , greater  of  i s considerable  heterogeneous than  they  Valley,  a more t r a c t a b l e p r o b l e m  information are  Okanagan  near source  Valley profile.  geophysical  the  km.  Crustal Profile  i n t e r p r e t a t i o n of  Kaiser the  c o r r e l a t e d with  of  the  Interior  geophysical  a c o u s t i c and  magnetic  contrasts. The very  c o n s i s t e n t f o r the  Figure to  4  8.  Hz  A gradual  arrivals  just  past  and  amplitude. The  early. are  80  km,  arrival The  be  an  is  not  A1375  abrupt  i s on  the  km  has  model  an  A1375  roughly f o r the  west  the  with  very  times of  along  the  6.1  velocity  at g r e a t e r the  Pocky  one  traces km/s on  2  sharp  arrival  i s approximately  is  section in  However, t h e  early arrival  margin of  refraction  Kaiser  anomalous f i r s t  upper c r u s t a l  in arrivals  on  pattern.  phase a r r i v a l are  crustal  i n amplitude  A1375,  lateral  reflected  increase  time at  km/s  80  general  crustal  reasonable  first  i s the  s c a t t e r e d , but  only  6.1  previously described  trace time  second  past  85  line.  A1375  km The  would  increase.  This  distances.  As  well,  Mountain  Trench  and  48  the  work o f B a l l y  decrease  in this  et al.(1966) area  arrival  i s probably  blast.  This  recordings  suggests that  i s more l i k e l y .  a seismic  i s quite  event  probable  experienced  a  Therefore,  unrelated  since  velocity the  t o the timed  a number o f  i n t e r f e r e n c e frcm  other  background  seismic  events. The The  attenuation  crustal  of a r r i v a l s a f t e r  p h a s e s beyond  e m e r g e n t and t h e t r a v e l km/s  line.  the trench  80 km a r e v e r y  i s real.  low a m p l i t u d e and  times a r e s c a t t e r e d around  A1675 h a s a c r u s t a l  arrival late  t h e 6. 1  by .1 s,  reflecting  the lower  velocity  Purcells.  The f i r s t  a r r i v a l a t A574 i s .2 s e a r l y .  could  be e x p l a i n e d  high  velocity  note  t h a t t h e 6.5  could  by i n a c c u r a t e  be e x t e n d e d  km/s  first  a r r i v a l branch km/s  arrivals  distances  w e l l with  t h e 6.1  et  slightly shot  less  point  appropriate  i s unlikely  do n o t show  to  produce a  a r r i v a l i s a t an  since  similar  a r e no c o r r e s p o n d i n g  second  t r a c e s from  very  emergent• phases..  km/s  line.  a p p e a r s t o be o f l o w e r f r e q u e n c y  o r by l o c a l  al.(1966)..  would  the K a i s e r  a r r i v a l s i n four  frequency  This  o f 8 km a t K a i s e r  velocity  interpretation  and t h e r e  The f i r s t  C173 a r e h i g h agree  115 km f r o m  However, t h i s at greater  layer  an a p p a r e n t  The A574 e a r l y  characteristics, arrivals.  with  i n the  I t i s interesting  a t a depth  of 2°, t h i s  a t about  (Dobrin,1960). distance.  basement  location,  t o t h e west a s i n B a l l y  a westward s l o p e  6.5  site  Paleozoic carbonates.  with  than  P r o t e r o z o i c sediments  E774 to  E774 and A173  The t r a c e B1675, which  because of severe  digital  49  filtering,  has  very  with  noisy  crustal belcw  phase  the  arrival A173,  an  picked  f o r C173  was  nearer  The  crustal  was  arrival  km,  results  of  Proterozoic basement  Bally  recks  attenuate geometries  f o r C173  i s a simple  the  synthesized.  of  north  6.5 by  km/s  was  at the  amplitudes  f o r the s t r u c t u r e .  and  using  any  km/s  solution.  6.1  blcck  is  velocity  crystalline  a study  (1972).  Mountain  crustal  layer  low  The  Using  upper  km/s  from  dimming  Rocky  picked.  attenuation  underlying  taken  not  dynamic  unknown e x t e n t .  Chandra  discontinuity crustal  The  at  kinematic  average  The  was  suggesting  6.1  amplitude  the  it  arrival  was  e x p l a i n the  e t a l . (1 9 6 6 ) ,  have an  the  upper  first  emergent,  n e c e s s i t a t e a more complex  velocity  geological  while  the  was  The  because  However, t h e  Paleozoic strata.  to the  arrival.  of t h i s ,  time  profile  specifically  i n F i g u r e 7 was  composed  km  of  the  very  model needed t o of t h i s  However, i t  been m i s s e d  abrupt,  small inhcmogeneities.  80  s late.  support  shot,  correct first  model  100  the  the  beyond  .3  have  In  characteristics,  the  may  level.  characteristics with  time  uncertain pick of  a t C173  noise  8 km  that  a arrival  The  Trench  number o f  done  could  reasonable  Figure seismic et  7.  Schematic  structure.  a l . (1966)-and  of t h i s  study.  discontinuity sedimentary to  t h e low  record  of near  Kaiser  It i s a compilation i s not  The  defined  poorly  velocity  amplitudes  s e c t i o n beyond  Mountain  zone  observed 80  by  the  from  Bally  data set  determined  a t t h e Rocky  low  source  km.  Trench  probably on  the  and  the  contribute Kaiser  15km  52  4  •  SYnthetic  Seismograms  Synthetic verifying  seismogram  seismic  models.  critical  r e f r a c t i o n s that  included  i n the  applicable  the  the  present  of  the  correctness  not  be  Disc  synthetic Chapman The  study  Ray  Theory  (1976) has used  (DBT)  i s described  provided  was  the  homogeneous m e d i a , the  head  large  with  by  Theory  study,  the  using  was  The  the  Disc  Ray of  be  Therefore, record  a general The  Wiggins  sections  indication  models  can  by of  procedure  The  corresponding  This  problem can  but  exact  Helmberger,1974).  p h a s e s and  that  DRT.  have t h i c k , homogeneous  contrasts.  approach  the  (1976).  computational  exaggerated.  Theory  of  d e r i v a t i o n of  model t o  more e x p e n s i v e  ( W i g g i n s and  identification trends  are  by  models t h a t  velocity  wave a m p l i t u d e s  obviated Ray  c o n s t r a i n i n g the  difficulty  with  can  seismic  HRGLTZ r o u t i n e d e v e l o p e d  laterally  layers  to the  a theoretical  Besides  has  the  method o f c o m p u t a t i o n  Wiggins.  also  medium.  interpretation.  of  generally  compute t h e  as  than  arrivals  However, no  u s e f u l only  the  a method  definitive.  seismograms  program  first  heterogeneous  are  of  t r e a t e d as  The  appear as  synthetics corresponding  of  offer  mere complex  i s a v a i l a b l e to  a laterally  computed  Phases  interpretation.  program  response of  computaticns  was  For  used  a suggestion  of  be  Generalized the  since  present only  the  amplitude  expected.  output  from  the  HRGLTZ r o u t i n e  includes travel  time  53  curves  and  synthetic  Kaiser  and  Highland  with 11  the  seismograms. Valley  ccrrespcnding  Figures  computed  demonstrate  most o f  described. 7.05  km/s  angle  the The  C273.  They c o r r e l a t e  refractions produce  effect from  very  B1675.  The  the well  the  intermediate  these  computed this  are  far  too  model, d e s p i t e  attempt  to  use  low  and  were  they  arrival  due the  on  at  to  to  large.  9 km  km.  thick  The  large  wide  amplitude  B674, A273, 120  reflections  on  and km.  The  and  layer,  B774, A2375,  distances less as  the  converge at  well.  than The  and 120  km  computed  r e f l e c t i o n branch the  with  upper  However, t h e  This  would be the  right.  seismic  km.  zones or  i s more  synthetics,  problems with  velocity  29  intermediate  the  b r a n c h and  440  cn  cf a  a r r i v a l s beyond  km, and  section  previously  match t h e  calculations  layer  the  record  addition  good c o r r e l a t i o n  l i n e s out  9  the  and  a depth of  observations  CST  There i s a g e n e r a l l y along  125  amplitudes  upper c r u s t a l r e f r a c t i o n frcm  at  with  mantle  the  include  simplest,  i s the  Pn  lower amplitudes by  the  respectively,  Numerous m o d e l s  Kaiser  this layer  with the  supported  also  t r a v e l t i m e model  near  the  large  corresponding  the  layer  1 s after  interference  of  major change  r e f l e c t i o n s from  the  are  difficulties.  simple  intermediate  phases about  are  the  interpretation  complex t h a n  11  10  models i n F i g u r e s  seismograms. are  8 and  sections,  f o r the  9 and  computed: t h o s e d i s p l a y e d  The  record  t r a v e l time c u r v e s  superimposed.  Figures  amplitudes  expected DPT  energy  from  method.  velocity gradients  fln to  Figure  8.  Kaiser  time curves. calculated Figure  The  from  9 using  s e c t i o n of travel  the the  time  Figure  2 with  curves  were  v e l o c i t y - d e p t h -nodel program  HRGLTZ.  travel  given  in  DISTANCE  (KM)  Figure  9.  velocity with  Synthetic model  Figure  8,  for Kaiser the  crustal  phase and  the  km/s  7.0  seismogram  profile.  amplitudes the  l a y e r are  section  of  wide a n g l e excessive.  the  In  and  comparison  near-surface  reflection  from  T-D/8.0  (SEC)  58  reduce  t h e s e a m p l i t u d e s seems f u t i l e ,  prominent Mountain There  crustal Trench  s i n c e t h e most  a m p l i t u d e c h a n g e a t A1375 n e a r t h e  i s certainly  related  i s evidence f o r a c r u s t a l  low  to l a t e r a l velocity  disappearance or delay c f the c r u s t a l  Rocky  changes.  zone i n t h e  p h a s e on  C173.  H o w e v e r , w i t h t h e p r e s e n t d a t a s e t , t h i s c o m p l e x a r e a on record  s e c t i o n cannot  The  be  resolved.  Highland Valley  profile  than the K a i s e r p r o f i l e .  section  d e s c r i b e d was  i n F i g u r e 11.  was  A first  t h e s i m p l e model d e t e r m i n e d previously  from  used  The  more d i f f i c u l t  At d i s t a n c e s b e y c n d large amplitude  are  especially  the f i r s t  t c produce  the  deep c r u s t a l critical  and  A1275 and  These  1966).  profile  s.  They  probably  interference  refracted  (Cerveny,  5.5  10.  phases from  the  Apparently the  sub-  r e f l e c t i o n s are of very s m a l l amplitude, suggesting  an a b r u p t b u t n o t f i r s t 1975).  B475.  travel  in Figure  a t about  constructive  critically  interface  data  synthetic  the Highland V a l l e y  phases a r r i v i n g  correspond to p o s t - c r i t i c a l between r e f l e c t e d  arrival  f i t of the corresponding  90 km,  e v i d e n t on  t c model  a p p r o x i m a t i o n p r o v i d e d by  time curve to the a c t u a l data i s d i s p l a y e d  has  the  order interface  S i n c e the s y n t h e t i c seismogram  h a v e t h e same d i f f i c u l t i e s 9 a s was difficult.  previously The  (Braile  and  Smith,  p r o g r a m HRGLTZ  will  w i t h the model d e p i c t e d i n F i g u r e  mentioned,  a comparison  of amplitudes i s  e x c e s s i v e head wave a m p l i t u d e s t h a t  p r o g r a m p r e d i c t s a t l a r g e d i s t a n c e s may  be  the  erroneous.  H o w e v e r , s e v e r a l o b v i o u s s h o r t c o m i n g s o f the' model c a n  be  59  Figure with  10.  Highland  t r a v e l time c u r v e s .  were c a l c u l a t e d Figure  11,  layer  model  also  Valley  from  The l a c k  The  t r a v e l time  the v e l o c i t y - d e p t h  and  amplitude  3  curves  model i n  o f d e f i n i t i o n o f the t h r e e  i n that  the upper  The  model i s  crustal  l o w e r c r u s t a l wide a n g l e r e f l e c t i o n  b r a n c h e s do n o t c o n s i s t e n t l y large  of Figure  i s p a r t i c u l a r l y evident.  unsatisfactory  refraction  section  correlate  a r r i v a l s appearing  past  with the 150  km.  DISTRNCE  (KM)  Figure  11.  Synthetic  velocity  model o f  Although  the  to  Figure  reasonable DPT.  10  Highland  generally can  seismogram  be  Valley  section profile.  poor f i t of the  improved,  a l t e r n a t i v e s could  many o f not  and  be  amplitudes the  most  modelled  by  39  63  verified.  The  tenuous. sharp and  existence  A two-layer  phases  showing  expression  arriving  i n the  at  A1075, A2175 and about  less  pick. near  first  Although surface  reflection  the  travel  effect the  from  the  future The  to  Perhaps,  the  the  km,  after  the  the  either  a deep c r u s t a l correspond low  to  velocity  Generalized be  low  Ray  agreement earlier  the  This  Theory to  the  is than  This  appearance  wide a n g l e  applied  with  velocity  zone.  They  this  phase.  l a t e r a l c h a n g e s , but  C1075,  angle  a r r i v a l s are  for  on  i n d i s t i c n t to  wide  layer,  are  apparently  generally  the  C475  no  A2075.  and  become t o o  The  later  C2175 and  and  is  A1275 and  there  s and  It i s also  predicts  programs w i l l  zone.  of The  reflections hypothesis  is  synthetic  this  problem  in  studies. present  distance  profile  cf  but  seismogram  and  220  suggests  top  km.  7  arrival,  deep c r u s t a l  a r r i v a l s would  untested,  the  the  due  first  refraction  After  be  section  large  220  time c u r v e  may  5 s on  arrivals correlate  crustal  inconsistent.  the  km  C1275 have  at  on  30  results.  Most i m p o r t a n t l y ,  a r r i v a l data  the  frcm  C275 and  obviously  2 s after  that  on  at  similar  phases a r r i v i n g  become e m e r g e n t a f t e r distance  interface  approximately  model.  sharp  the  model g i v e s  correlations  unaccounted  arrive  of  as  study  range of  well  with  additional  as  does not  define  80  to  180  might  be  accomplished  more s o p h i s t i c a t e d  km  cn  the the  deep s t r u c t u r e Highland  from  the  interpretation  geo'physical c o n t r o l ,  the  Valley data.  technigues  interpretation  can  in  64  be  improved.  modellinq layer  that  between  shallower, at  However, i t i s a p p a r e n t  the  there 80  and  probably  Highland  (assuming t h a t  are  not  crustal  A low  Highland  net  end  Valley  least-Squares  term-term  obvious method  arrivals.  method d e s c r i b e d  function  of  Highland  this  Delay  was  and  applied  requires  apparent  velocity  higher  profile  towards the  from  and  that  the  Kaiser  arrivals  average from  Highland  Since  the  Valley  Kaiser  considerably, synthetics  and  the  assuming  valid.  Times  changes a l c n g  Forsyth of  et  the  of  the  a l . (1974) and  was  Fourier  fitted  The  first  f i t used  lower  layer  velocity.  there  layer not  to  Pn  the  first  A (as  t r a v e l time a preset In  v e l o c i t y was a high  used. terms  proportional  be  made a  "Delay-Time-Function"  was  lower  profile  i n t e r p r e t i n g the  linear  offset distance the  at  west  i n the  the  generally  attractive for  by  than  deep c r u s t a l  situation.  not  lateral  least-sguares.  an  of  Valley  increase  are  position)  iterations,  It i s  i n t e r p r e t a t i o n , the  determined  composed  distance  points.  the  A simplified version  surface  both shot  interpretations differ  homogeneity  The  of  In t h i s  alter  lateral  method  from  synthetic  v e l o c i t y deep c r u s t a l  v e l o c i t y zone i n c l u d e d  structures  offset  km  the  crustal  using  2C0  t h i c k e r , and  phases).  model would  time  a high  v e l o c i t y would  Kaiser.  5.  be  Valley  end  Pn  may  from  delaya  data  average  subsequent  to  the  time-term  updated.  This  c o r r e l a t i o n between  65  shot/receiver the  upper  this  distance  layer  affects  and  average  position  velocity  the c o r r e s p o n d e n c e  the depth t o the r e f r a c t i n g uncertain are  Pn  travel  available,  unfulfilled.  The  the  Because  crustal  i s very  time  only  The end,  average  as s u g g e s t e d  km/s.  velocities  velocities  velocity  delay-time  solution  final  the p r e l i m i n a r y  was  7.82±.04 km/s  solution.  There  wave l e n g t h , additional  of F i g u r e  The  for this  12a.  upper  The  (Figure  because least  of t h i s  solution,  6.5  A range  of  f o r the  plane r e s u l t e d  apparent  12b.  Valley  crustal  cf c o n s t r a i n i n g  8)  oscillation, the  wavelength  The  least  which  had  the  i n the  travel was  third  time  not  of i t s l a r g e  sguares  of the o b s e r v a t i o n s about term  depths.  model.  average  results  solutions  i s an  make t h e  11, i s n e a r  Kaiser  given in Figure  work.  may  with a standard d e v i a t i o n  Fourier  solution  velocity  km/s  to a dipping  delay time  previously  Highland  standard deviation  The  sources  t o f i t t h e d a t a , but h i g h e r  c o r r e s p o n d i n g t o B273  in  the  were used  assumed.  surface  observation  a t the  f o r the  T h e r e f o r e , a 6.5  was  iteration  km/s  gave a l o w e r  solutions.  velocity  only three  o f mantle  i n t h e model c f F i g u r e  I t i s n e a r 6.3  average  the  crustal  indicative  and  nearly  structures  f o r o p p o s i t e ends c f t h e p r o f i l e indirectly  since  Highland Valley  determined terms  Also,  between t h e d e l a y t i m e s  reguirement  different  1972).  s h o u l d net change  interface.  t i m e s from  the f i r s t  (Morris,  used i n residual  mantle  velocity  of  s f o r the  .14  w i t h a 165  line. was  squares  km  An  included  in  mantle  a standard  deviation  Figure The  12a.  Highland  Delay  V a l l e y and  located  a t -225  Valley)  and  from was  each  iteration velocity of  the  225  squares  to  be  solution  6.5  km.  km/s.  This  s.  cycle)  The  observations  is a  velocity third refractor  standard  Note t h e with  a  are  (Highland  in a least-squares  i s .1U  (of one  points  Crosses denote  plane.  average c r u s t a l  o f 7,82±.04 km/s.  solution  for a  Kaiser shot  (Kaiser) The  resulting  oscillation length.  and  source.  assumed  time  165  deviation  apparent km  wave  Figure  12b.  term.  The  Delay time s o l u t i o n assumed  6.5  km/s,  .08  s standard  refractor  giving  and  Kaiser  one  average c r u s t a l v e l o c i t y  a third iteration solution  deviation.  velocity  disagreement  with  was  The  was with  calculated  7.80+.03 km/s.  in  the  s l o p e s of  the  data  set  about  solution.  the  Fourier  Note  Highland  the Valley  a  70  of the  .08  s,  was  7.80±.03 km/s.  oscillation  delay  was  approximately  times range frcm  note that the  The  3.0  t o 3.6  solution i s valid  peak t o peak a m p l i t u d e .5  s.  s.  The  of  calculated  I t i s important  c n l y where d a t a  to  points  exist. The the  i n t e r p r e t a t i o n of the  separation  topography. are  L a t e r a l v e l o c i t y changes i n the , but  s o l u t i o n s f o r a 7.8  the  km/s  The  previously  models would r e s u l t i n a d e l a y  Highland Valley to .Us  i f there  disccntinuity. term of the cosine  stability  Kaiser.  were no This  delay  The  km  lateral  cn  the  scale of  1.  profile.  Figure  of  Because of  delay  time  determined  Assuming t h a t  not  upper  time i n c r e a s e  changes i n the  the the  the  from  from  .2  Mcosine  most o f  at the  km  This  near the  Kaiser  end.  o c c u r s between 0 corresponds to  the  lateral  v e l o c i t y change, the at the  Kaiser  to  the  Arrow L a k e s t o Kootenay Lake  on delay  end  of  velocity variations into  in a subjective  s o l u t i o n i n d i c a t e s a 7.8 a b o u t 33  12.  t o depths i s toe l a r g e  Taking  consideration  km  mantle  term i s r e l a t e d to average c r u s t a l v e l o c i t y , then a  time conversion the  upper  w o u l d a c c o u n t f o r most o f t h e  time s o l u t i o n .  area from j u s t east Figure  mantle  m a g n i t u d e w o u l d be  sudden decrease i n v e l o c i t y a p p a r e n t l y 60  of the  involves  v e l o c i t y suggests that t h i s i s  a major c o n s i d e r a t i o n .  to  time s o l u t i o n s  of c r u s t a l v e l o c i t y v a r i a t i o n from  also possible  crustal  delay  km/s  f a s h i o n , , the  delay  M-discontinuity  time  dipping  from  Highland V a l l e y to a pcorly defined  40  71  The  a l t e r n a t i v e would  reflected at  least  mantle topography part  interpreted associated  of  as  the  being  with  steeply  In  t c the  t o Ckanagan Lake the  Arrow l a k e s  encouraging compensate  km/s  from  the  and and  since  lcwer  case,  Kootenay  lateral  for a l l of,the  short  time s o l u t i o n s determined Forsyth,  Forsyth  (1975) n o t e ,  with  increased  an  systematic time  curve,  the  disagreement suggest  that  velocity  indications  are  evident  likely  both  relatively present.  short  a steeply  region area  dc  improvement  of  in this  points  Beth  study.  horizontal velocity wavelength  together  significant  variations.  cf  to  to  the the the  and  a solution with on  a  a delay  lateral these  Therefore,  gradients  crust-mantle  of  immediately  lack  are  seem  well with  Berry  there  between  character  match  f o r areas  reversed  adjacent  not  However, a s  between  would  interpretation i s  times  iterations,  dipping  boundary  described  wavelength  of  that  i s actually  in velocity  delay  times  iray i m p l y  the  This  delay  1975).  number o f  average c r u s t a l  that  the  the  branch  mantle  beneath  changes  delay  and  the  Lake.  time curve.  (Berry  time  crust  previously  delay  west  This  travel  locally  the  Also,  assume t h a t  r e f r a c t i o n s from  this  east  to  directly.  7.35  critical  M-discontinuity. dip  be  it is  and  topography  are  72  6.  Discussion  The  interpretation  general  agreement  primary  feature  east,  with  The  of this  depth  study  models d e r i v e d  near source  although  information  results  layers,  velocity  35 km.  Although  i t does  g r a v i t y data  The t o the  the  confirm  ( S t a c e y , 1973) .  was a l s o n o t d e f i n i t i v e , interesting  were t h e s h o r t  smooth v a r i a t i o n s i n t h e d e l a y crustal  i si n  M-discontinuity dipping  near  from  as d e s c r i b e d  s t u d i e s o f the r e g i o n .  i s limited,  i t i n d i c a t e d seme  interesting  profile  previous  i s a 7.8 km/s  an a v e r a g e  resolution previous  with  of t h i s  wavelength  The mcst  but very  time i n t e r p r e t a t i o n ,  and t h e u n d e v e l o p e d  zone i n t e r p r e t a t i o n  features.  possibility  f o r the Highland  t h e deep  o f a low  Valley  profile. A deep c r u s t a l suprising similar with in  s i n c e Chandra  7.0 km/s  a gradual  this  l a y e r from  study  the Kaiser data  and Cumming  l a y e r immediately  taper  than  for offset  at  as f a r west a s K o o t e n a y  least  indistinct  The  eastward  in this  deep c r u s t a l  interpretation  of Kaiser,  previously  suggested.  d i s t a n c e s , the l a y e r apparently  at greater  complications  a  The t h i c k n e s s c a l c u l a t e d  was  Allowing  suggested  to the east  t o t h e west.  was g r e a t e r  (1972)  was n o t  Lake.  exists  The a r r i v a l s  become  d i s t a n c e s , and, c o n s i d e r i n g t h e o t h e r area,  this  i s very  reasonable.  l a y e r i n the Highland  i s more t e n u o u s .  Valley  The p o s s i b i l i t y  d i p i n t h e mantle, suggested  of a  by t h e d e l a y  steep  time  73  study,  complicates  branches from the  data  Pn  i s of  westward f r o m Highland  (increasing elsewhere  s e c t i o n s of  poorer a shot  with  striking described  depth).  travel From a  i n the  Forsyth  Columbia, of  this  extensively seismic  Geophysical  can  be  tectonic  Therefore,  Review o f  discussed  by  structures  t h a t would  relating  considered  upper  greatest  have  effect  interpretation  on  study  of the  and  that i s  I , may  have a  Cordillera,  a  definitive study  and  (1975)  i m p l i c a t i o n s of  not  this  geophysical  a  east-west  of the  s i n c e the  observations  the  Columbia.  can  tc  Cretaceous.  undergone  The  subduction  Vertical deep c r u s t  activity  this  and  t h a t has  parameters.  using  The  be  features primarily  has  km/s  t h a t such  Forsyth  c h a r a c t e r i z e d the  present  found  present  s i n c e then.  i t i s probably  been  latitude  considered  formed  activity  have p r o b a b l y  m a n t l e , and  they  t o 7.0  in B r i t i s h  geophysical  in this  or t r a n s c u r r e n t type tectonics  that  an  6.5  history,  possible tectonic  interpretations  simplified  region  Eerry  the  well.  made between t h e  complications  east of  Chapter  deep c r u s t a s  models.  km  indicate  g e o l o g i c a l complexity  not  refraction  tectonic  not  may  because of i t s u n c e r t a i n t e c t o n i c  hypothetical  frcm  Also,  directed  (1975) f o u n d  i t has  51°.  90  crustal  curve.  profile  of v e l o c i t y Since  e x p r e s s i o n i n the  correlation  time  mantle boundary near t h i s  Because of the and  and  c n l y south  upper  the  approximately  layer  in Eritish  o f s e p a r a t i n g deep  quality. point  crustal  exists  general  problem  V a l l e y , Berry  intermediate  layer  the  The  viewpoint.  the  74  reduces  the  The includes Eastern  Cordilleran  Thermal  mcst  Interior  of  the  Metamorphic  probably Pacific the  speculative possibilities  an  effect  plate  latitudes  and cf  Farallon  (now  a  and  Metaracrphic associated The of a  lew  complex  zones  may  upward  late-Mesozcic  te  mobility of  to  of  of  the  boundaries.  The  line  the  Valley  Okanagan Arrow  Highland  Lake  Lakes  and  and  the  metamorphism,  mildly  affected.  increasing  delay  metamcrphism. either with  the  this  ccrrelaticn  of  times  The  lower view.  Therefore, are  lateral  crust  or  the  Mechanisms more  severe  regimes. used  as  a  measure  activity  allows  along  occurs  Mountains  with  the  less  were  Lake,  the  between  between  somewhat  Okanagan  with  only  the  decreasing  previously described  mantle  that  Eastern  and  region  correlated  changes  the  profile  Purcell  well  be high  metamorphism  The  of  may  discontinuities  experienced  east  at  relatively  thermal  Kaiser  the  plate  imbricate  thermal  Lakes.  Lake  while  events  heating  time  East  al,1971;  beneath  intense  to  Arrow  Kootenay  severe  most  the  et  metamcrphism  delay  the  Fuca)  The  the  anomalous  thermal of  to  these  surface  recent  association  of  mantle  related  de  thermal  system  upper  a l l cf  of  (Berry  (Godwin,1975).  velocity  Belt  Juan  study  late-Mesozoic  more  intensity  direct  present  probably  Anticlinorium, i s  the  associated  shallow  Purcell  which  and  sutduction  the  subducticn  Plateaux  Tertiary  The  angle  and  Zone,  of  Atwater,1970) . with  Belt  Anomaly  considerably.  could  might  metamorphism  be  consistent  e x p l a i n the with  in  either  apparent a  higher  75  average v e l o c i t y lower v e l o c i t y The  i n t h e c r u s t o r a s h a l l o w e r and  upper mantle a r e h i g h l y  shallow, high  postulated  velocity  Metamorphic  Eelt  could  1976).  of the  be f o r m e d by a  p r o c e s s s u g g e s t e d by R.L.  Armstrong  Under i n t e n s e h e a t i n g  speculative.  lower c r u s t a l  beneath t h e west s e c t i o n  with  perhaps  layer  Eastern  differentiation  (personal partial  communication,  cr f u l l  melting,  the heavier gabbroic rocks could  s e p a r a t e downward f r o m t h e  lighter,  r o c k s which would  lower v e l o c i t y  surface layer.  granitic  I f the degree o f t h i s a c t i v i t y  to the r a t e of u p l i f t ,  ( P r i c e and  Mountjoy,1970).  and,  for  only  thermal e f f e c t s  or upper  was  by C a n e r  anomaly  mantle anomaly transition  density  (1973).  mantle boundary  associated  (1971).  The could  with  crust  d e p t h o f 10 t o 15 km, be i d e n t i f i e d  Belt  later  with e i t h e r  a  i n t h e f o r m e r c a s e , o r a deep c r u s t / u p p e r i n the l a t t e r  zone  conductive layer of the r a p i d  presumably,  the conductive, hydrated lower  m o d i f i e d t o 20 t o 40 km, crustal  lateral  o t h e r evidence i n the E a s t e r n Metamorphic  a deep c r u s t a l  proposed  related  However, t h i s  i n c r e a s e c o n t r a d i c t s the f i n d i n g s of Stacey The  the  l a y e r s c o u l d a c c o m p l i s h a net  l a t e r a l change i n average c r u s t a l v e l o c i t y density  was  t h e n s u r f a c e e r o s i o n and  movement o f t h e n e a r s u r f a c e  form  case.  Also, the  marking the e a s t e r n boundary i s near Kootenay  increase  i n the delay  o b s e r v a t i o n s are c e r t a i n l y nature of the a s s o c i a t i o n  magnetic of the  Lake, the e a s t e r n times.  boundary  These  r e l a t e d , although the i s o b s c u r e d by p o o r  precise  resolution.  76  Anomalous expected (1976)  near  indicates base  observed the  major  within that  i n t h e upper  lateral  has suggested  determined  the  behaviour  that  thermal  mantle  boundaries.  t h e lew upper  mantle  the C o r d i l l e r a n Thermal  t h e Gutenburg Since  at the surface  probably  M-disccntinuity  as w e l l ,  anomalous  mantle  boundary  analogous  t o t h e metamorphic  smaller have  vary  be  velocity  zcne  Zcne  i s a t c r near  scale  thermal  features  their  origins  belcw  t h e depth  may  also  Wickens  Anomaly  low v e l o c i t y  of the crust.  would  to this  laterally  variations  already  i n a  i n the  fashion  surface  features. While  the general  of  the central  to  recent  The  Kootenay terms  west  early  relative  When  into  a much  account, geological  necessary Mesozoic  Lakes  such  although  ancient  better  geology  could  alsc  and t e c t o n i c s .  history.  between  be e x p l a i n e d  I . Duncan  probably  i n  (personal  Metamorphic  crustal  i t sposition  h a s been  geophysical  older  the Eastern  lateral  and mantle  late-Mesczcic  velocity  blcck  had n e t  since the variations  understanding  s i t u a t i o n than  to relate  tc  was a s e p a r a t e  to the craton,  Proterozoic.  crustal  that  crust  a much  novements.  1977) s u g g e s t s  c f t h e Arrow  relate have  Lakes  tectonic  i n the Paleozoic,  changed  and  i n average  and t h e Arrow  cf horizontal  communication, Belt  t h e d e t a i l s may  increase  Lake  o f t h e deep  C o r d i l l e r a probably  events,  possible  features  of the  are taken geophysical  accomplished i s  parameters  to the  pre-  77  7.  Conclusions  1.  In o r d e r  to obtain  heterogeneous  areas  such  plan  f o r the experiment  used  with  study for  a station  suggests  example  Creek  that  Trench  Kaiser  profile  major  control,  resolution  necessary There  crustal  a r e major  velocity  Besides upper  possible  mantle  Kaiser  Valley  shot  an  could  The  be  present  contrasts  zone  areal  do  of the  exist;  Guichcn  to delineate  events  an  do  n o t have  feature.  i n both  depth,  i s  the  at short  average  wavelengths  Belt.  shorter  t o about  wave  length  depth  close  t o 7.8  km/s  approximate 42  wavelength  with  since  There  changes,  of velocity from  methods  this  Mountain  reversed  discontinuity  refraction  lateral  t h e Rocky  but without  of this  be t h a t  that  km  just  depth  variations, generally  o f 33 km  t o t h e west  near the  of the  point.  The s h o r t  correlated  show  and t h e mantle  to the east  Highland  5.  core  boundary,  the E a s t e r n Metamorphic  dips  1 km.  than  velocity  results  the nature  the  the  Plateaux  as f a n p r o f i l i n g )  velocity  lateral  I t may  4.  (such  interesting  speculative.  3.  resolution i n  as t h e I n t e r i o r  spacing less  i n the high  i s a  seismic  in  crustal  Batholith. The  2.  upper  the  delay  the thermal  time  history  anomalies  c a n be  and v e r t i c a l  tectonic  Jurassic.  i s strong  evidence  f o r an i n t e r m e d i a t e  crustal  78  layer  of  between the  v e l o c i t y 7.05 100  and  200  km/s,  km  frcm  interpretation cf  exist  between  point  at  a  80  and  depth  of  depth the  poorer 180  15  km  to  29  Kaiser  data, from  24  km,  km  a  shot  7.35  the and  and  thickness  point.  km/s  layer  Highland  Valley  a  thickness  of  9  km  Based  on  may shct  6  to  10  km. 6.  This  study  Forsyth,  1975)  channels  can  ratio  2  than  cf 20  tested  by a  shots  that  the  would  imitediate  most  in  was  are  to  in  be  shot A  make  used  as  least  compatible,  as  velocity  spacing  station  of  less  the  average more  anomalies  analysis.  particularly each  i f  other.  station  be  (which  features),  time-term  multiple  valid.  would  and  be  locations  recording  approach  time-term  with  and  signal-to-noise  experiments  that  (Berry  interpretation cculd  significant  suggests  a  stations  time  lew  station  well  lateral  to  conjunction  an  at  seismic  delineating  adapted  of  by  delay  future,  of  others  and  with  regular  number  a  well  points  separated  Eamford (1976),  approaches  a  unigueness  i n t e r e s t i n g and  experiment by  are  and  by  structure  defined  better The  suggestions  lateral  be  profile.  successful the  only  varying  along  spacing  that  or  km.  confirms  i f  For  most are  often  the  Recent  work  profiling  they  are  designed  79  LIST  OF  REFERENCES  A g e r , C . A . , U l r y c h , T . J . , and M c M i l l a n , H . J . 1973. A gravity model f o r the G u i c h c n Creek b a t h o l i t h , south-central B r i t i s h C o l u m b i a . C a n . J . E a r t h S c i . , 1 0 , pp. 920935. A h e r n , T . K . 1975. An c * V O * study of water flow i n n a t u r a l s n o w . U n p u b l . M.Sc. T h e s i s , Univ. B r i t i s h Columbia, V a n c o u v e r , B r i t i s h C o l u m b i a . 164 pp. 6  A t w a t e r , T . 1970. Cenozcic America.  Implications of plate tectonics f c r the t e c t o n i c e v o l u t i o n of western North E u l l . G e o l . S o c . Am.,81, p p . 3 5 1 3 - 3 5 3 6 .  Bally,A.w., Gordy,P.L., and Stewart,G.A. 1966. Structure, s e i s m i c d a t a and o r o g e n i c e v o l u t i o n o f s o u t h e r n C a n a d i a n R o c k y M o u n t a i n s . B u l l . C a n . P e t . G e o l . , 14, pp. 337-381. Eamford,D. R.  1976. astr.  MOZAIC t i m e - t e r m a n a l y s i s . S o c , 44, pp. 433-446.  Bennett,G.T. 1973. A s e i s m i c r e f r a c t i o n s o u t h e r n Rocky Mountain T r e n c h . Thesis, Univ. E r i t i s h Columbia, C o l u m b i a . 70 pp.  Geophys.  J.  survey along the Unpubl. M.Sc. Vancouver, British  Bennett,G.T., C l o w e s , B . M . , and E l l i s , R . M . 1975. A seismic r e f r a c t i o n s u r v e y a l o n g the s o u t h e r n Rocky Mountain T r e n c h , C a n a d a . B u l l . S e i s m . S o c . An., 65, pp. 3754. B e r r y , M . J . , J a c o b y , W . R . , N i b l e t t , E . S . and S t a c e y , P . A . 1971. A review of g e o p h y s i c a l studies i n the Canadian C o r d i l l e r a . C a n . J . E a r t h S c i . , 8, p p . 7 8 8 - 8 0 1 . B e r r y , M . J . and F o r s y t h , D . A . 1975. S t r u c t u r e o f C o r d i l l e r a f r o m s e i s m i c r e f r a c t i o n and Can. J . E a r t h S c i . , 12, pp. 182-208.  the Canadian other data.  B l a c k w e l l , D . D . 1969. H e a t - f l o w d e t e r m i n a t i o n s i n t h e n o r t h w e s t e r n U n i t e d S t a t e s . J . Gecphys. Res., pp. 9 9 2 - 1 0 0 6 .  74,  B r a i l e , L . H . and S m i t h , R . B . 1975. G u i d e t o t h e interpretation c f c r u s t a l r e f r a c t i o n p r o f i l e s . G e o p h y s . J . R. astr. Soc. , 40, pp. 145-176.  80  C a m f i e l d , P . A . and G o u g h , D . I . 1 9 7 5 . A n o m a l i e s i n d a i l y v a r i a t i o n magnetic, f i e l d s and s t r u c t u r e under t h e n o r t h - w e s t e r n U n i t e d S t a t e s and s o u t h - w e s t e r n C a n a d a . G e o p h y s . J . R. a s t r . S o c , 4 1 , pp. 1 9 3 - 2 1 8 . Campbell,R.B. 1973. S t r u c t u r a l c r o s s - s e c t i o n and t e c t o n i c model o f t h e s o u t h e a s t e r n C a n a d i a n C c r d i l l e r a . Can. J . E a r t h S c i . , 1 0 , pp. 1 6 0 7 - 1 6 2 0 . C a n e r , B . , A u l d , D . R . , C r a g e r t , H . and C a m f i e l d , P . A . 1 9 7 1 . G e o m a g n e t i c d e p t h - s o u n d i n g and c r u s t a l s t r u c t u r e i n w e s t e r n C a n a d a . J . G e o p h y s . R e s . , 7 6 , pp. 7 1 8 1 - 7 2 0 1 . Caner,B.  1971. Q u a n t i t a t i v e i n t e r p r e t a t i o n o f geomagnetic d e p t h - s o u n d i n g d a t a i n w e s t e r n Canada. J . Geophys. Res.,  76,  pp.  7202-7216.  C e r v e n y , V . 1 9 6 6 . On d y n a m i c p r o p e r t i e s o f r e f l e c t e d a n d head waves i n t h e n - l a y e r e d e a r t h ' s c r u s t . G e o p h y s . J . R. a s t r . S o c , 1 1 , pp. 139- 147. C h a n d r a , N . N . and C u m m i n g , G . l . 1 9 7 2 . S e i s m i c r e f r a c t i o n s t u d i e s i n w e s t e r n Canada. Can. J . E a r t h Sci.,9,pp.  1099-1109.  C h a p m a n , C H . 1 S 7 6 . E x a c t and a p p r o x i m a t e g e n e r a l i z e d r a y t h e o r y i n v e r t i c a l l y inhomogeneous media. Geophys. J . R. a s t r . S o c , 4 6 , p p . . 2 0 1 - 2 2 3 . Dobrin,M.E. 1960. I n t r o d u c t i o n t o G e o p h y s i c a l M c G r a w - H i l l Beck C o . , N.Y. 446 pp.  Prospecting.  D r a g e r t , H . 1973. A t r a n s f e r f u n c t i o n a n a l y s i s o f a geomagnetic depth sounding p r o f i l e across c e n t r a l B r i t i s h C o l u m b i a . C a n . J . E a r t h S c i . , 1 0 , pp. 1 0 8 9 1098.  F o r s y t h , D . A . , E e r r y , M . J . and E l l i s , R . M . 1974. A r e f r a c t i o n s u r v e y a c r o s s t h e C a n a d i a n C o r d i l l e r a a t 54 N. Can. J . E a r t h S c i . , 1 1 , pp. 5 3 3 - 5 4 8 . Godwin,C.I. 1975. I m b r i c a t e s u b d u c t i o n z o n e s and t h e i r r e l a t i o n s h i p w i t h upper C r e t a c e o u s t c T e r t i a r y p o r p h y r y d e p o s i t s i n t h e C a n a d i a n C c r d i l l e r a . Can. J . E a r t h S c i . , 1 2 , pp. 1 3 6 2 - 1 3 7 8 . H a i n e s , G . V . , H a n n a f o r d , V . , and R i d d i h o u g h , R . P . 1 9 7 1 . M a g n e t i c a n o m a l i e s o v e r B r i t i s h C o l u m b i a a n d the a d j a c e n t P a c i f i c Ocean. C a n . J . E a r t h S c i . , 8, pp.  387-391.  81  J e s s o p , A . M . a n d J u d g e , A . S . 1971. flow i n s o u t h e r n Canada. pp. 711-716.  Five Can.  measurements of heat J. Earth Sci., 8,  Kanasewich,E.R. 1968. Precambrian r i f t : g e n e s i s o f s t r a t a bound o r e d e p o s i t s . S c i e n c e , 161, pp. 1002-1005. I K a n a s e w i c h , E . F . , C l o w e s , P . M . , a n d M c C l o u g h a n , C . H. 1 9 6 9 . b u r i e d Precambrian r i f t i n western Canada. T e c t o n o p h y s i c s , 8, p p . 5 1 3 - 5 2 7 .  A  K a n a s e w i c h , E . E . 1975. Time S e q u e n c e A n a l y s i s i n G e o p h y s i c s . U n i v e r s i t y o f A l b e r t a P r e s s . 364 p p . Law,L.K.  and R i d d i h o u g h , R . P . 1971. A g e o g r a p h i c a l relation between g e o m a g n e t i c v a r i a t i o n a n o m a l i e s and t e c t o n i c s . Can. J . E a r t h S c i . , 8, p p . 1094-1106.  L e e c h , G . B . 1965. The R i f t System, 329.  Rocky Geol.  M o u n t a i n T r e n c h , i n : The H c r l d S u r v . C a n . P a p e r 6 6 - 1 4 , pp. 3 0 7 -  Monger,J.w.H., S o u t h e r , J . G . , and G a t r i e l s e , H . Evolution c f the Canadian C o r d i l l e r a : t e c t o n i c m o d e l . Am. J . S c i . , 2 7 2 , p p .  1972. a plate 577-602.  M o r r i s , G . B . 1972. D e l a y - t i m e - f u n c t i o n m e t h o d a n d i t s a p p l i c a t i o n t o t h e Lake S u p e r i o r r e f r a c t i o n d a t a . G e o p h y s . R e s . , 77, pp. 294-314.  J.  N o r t h c o t e , K . E . 1969. G e o l o g y and g e c c h r c n o l c g y o f t h e G u i c h c n C r e e k b a t h o l i t h . E.C. D e p t . o f M i n e s a n d P e t r o l e u m R e s o u r c e s B u l l e t i n . No. 5 6 . P r i c e , R . A . a n d M o u n t j o y , E . H . 1970. G e o l o g i c s t r u c t u r e o f t h e C a n a d i a n R o c k y M o u n t a i n s b e t w e e n Eow a n d A t h a b a s c a R i v e r s . G e o l . A s s o c . C a n . , S p e c . P a p . 6, p p . 7-26. R e i t z e l , J . S . , Gough,B.I., P o r a t h , H . , and Andersen,C.W. 1970. Geomagnetic deep s o u n d i n g and upper mantle s t r u c t u r e i n w e s t e r n U n i t e d S t a t e s . G e o p h y s . J . R. a s t r . S o c . 19, pp. 213-235. S p e n c € , G . D.,. C l o w e s , R . M . , and E l l i s , R . M . 1977. Depth l i m i t s on t h e M - d i s c c n t i n u i t y i n the s o u t h e r n Rocky M o u n t a i n T r e n c h , C a n a d a . B u l l . S e i s m . S o c . Am., 67, in press. S t a c e y , S . A . 1S73. G r a v i t y a n o m a l i e s , c r u s t a l s t r u c t u r e and p l a t e t e c t o n i c s i n the Canadian C o r d i l l e r a . Can. J . Earth Sci., 10, pp. 615-628.  82  U l r y c h , T . J . and B i s h o p f T . H . 1975. Maximum entropy s p e c t r a l a n a l y s i s and a u t o r e g r e s s i v e decomposition. Rev. Geophys. Space P h y s . , 13, pp. 183-201. Wanless S.K. and Ressor J . E . 1974. Frecamcrian z i r c o n age of o r t h c g n e i s s i n the Shuswap Metamorphic Complex, B r i t i s h C o l u m t i a . Can. J . E a r t h S c i . , 12, pp. 326332. W h e e l e r , J . O . and G a b r i e l s e , H . 1972. The C o r d i l l e r a n s t r u c t u r a l province. In: Variations in Tectonic S t y l e s i n Canada, R.A. P r i c e and R.J.W. Douglas ( E d s . ) . G e o l . a s s o c . C a n . , Spec. Pap. 11, pp. 9-81. W h i t e , * . R . H . , B o n e , M . S . , and M i l n e , W.G-. 1 968. Seismic r e f r a c t i o n surveys i n B r i t i s h Columbia-A p r e l i m i n a r y i n t e r p r e t a t i o n . Am. Geophys. Un. Geophys. Mcnc;12, pp. 81-91. W i c k e n s , A . J . 1977. The upper mantle of southern B r i t i s h C o l u m t i a . Can. J . Earth S c i . , 14, i n p r e s s . W i g g i n s , R . A . and H e l m t e r g e r , D . V . 1974. S y n t h e t i c seismogram computation b y expansion i n g e n e r a l i z e d r a y s . Geophys. J . E . a s t r . Soc. , 37, pp. 73-90. W i g g i n s , R . A . 1976. Body wave amplitude Geophys. J . R. a s t r . S o c , 46, York,E.  calculaticns-II. pp. 1-10.  1969. Least sguares f i t t i n g of a s t r a i g h t l i n e with c o r r e l a t e d e r r o r s . Earth P l a n e t . S c i . L e t t . 5, pp. 320-324.  

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