UBC Undergraduate Research

The geologic evolution of the Okanagan Valley shear zone near Oliver, British Columbia, Canada Towell, Moses Jesus Mar 31, 2015

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
52966-Towell_Moses_EOSC_449_2015.pdf [ 116.05MB ]
Metadata
JSON: 52966-1.0053621.json
JSON-LD: 52966-1.0053621-ld.json
RDF/XML (Pretty): 52966-1.0053621-rdf.xml
RDF/JSON: 52966-1.0053621-rdf.json
Turtle: 52966-1.0053621-turtle.txt
N-Triples: 52966-1.0053621-rdf-ntriples.txt
Original Record: 52966-1.0053621-source.json
Full Text
52966-1.0053621-fulltext.txt
Citation
52966-1.0053621.ris

Full Text

THE GEOLOGIC EVOLUTION OF THE OKANAGAN VALLEY SHEAR ZONE NEAR OLIVER, BRITISH COLUMBIA, CANADA  by   MOSES JESUS TOWELL    A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF  THE REQUIREMENTS FOR THE DEGREE OF   BACHELOR OF SCIENCE (HONOURS)  in  THE FACULTY OF SCIENCE (GEOLOGICAL SCIENCES)  This thesis conforms to the required standard  ………………………………...…………………….. Dr. Kenneth Hickey       &       Dr. James Scoates   THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) MARCH 2015  © Moses Jesus Towell, 2015       ABSTRACT The Okanagan Valley shear zone (OVsz) is approximately 1.5 km thick and delineates the western margin of the Shuswap metamorphic complex (SMC).  The western contact of the OVsz is defined by the Okanagan Valley detachment fault  (OVdf), an approximately 20° west-dipping, extensional detachment that facilitated exhumation of the Shuswap metamorphic complex during the orogenic collapse of the southeastern Canadian Cordillera in the Eocene.  The field area studied is located to the north of Oliver, B.C. and west of Vaseaux Lake.  This study observes and constrains its geologic evolution through petrographic and structural analysis of the rocks within the footwall.  Two main lithologies are observed within the OVsz, the Green Lake metasedimentary complex (GLmc), the host rock, and the Mt. Keogan intrusive complex.  Intense ductile deformation is observed through a penetrative mylonitic fabric that overprints both lithologies. A top-to-the-west-north-west sense of shear has been suggested through kinematic indicators.  iii  ACKNOWLEDGMENTS  First of all, I’d like to acknowledge that I am on Musqueam Territory.  Thank you for allowing me to follow my dreams here.  Your ideals and struggles do not go unnoticed.    Secondly, I’d like to extend thanks to Diego MacDugall, for being the instigator.  Hiking with you was a constant adventure.  But mostly for lugging out 30lbs of rock a day and being able to make me laugh consistently.  That was an unforgettable trip.  This effort is mostly dedicated to my educators.  Ken Hickey and James Scoates leave me in constant awe when learning from them. Thank you for the opportunity to work on such an incredible project, especially one that will continue to grow year after year through the work of new students.  I cannot wait to see what has been learned in 10 years.  Lori Kennedy, you are the reason I’ve done so well in Structures.  Your passion is inspiring, and you make it so understandable. To all three of you, thanks for spending so much time with me talking and throwing ideas around, especially in the field.  You can make my head spin, but it is an invaluable way to learn.    Mary Lou Bevier, thank you for constantly being available for questions and guidance and keeping me on track.  The little emails work!  I’d like to thank Nader Mosthigimi for being my office mate, for understanding the complexities of writing a thesis and just being around to bounce ideas (and jokes) off of.   I had a wicked time.    I’d also like to thank the rest of the faculty and students from the Earth, Ocean and Atmospheric Science department.  The education learned here was unparalleled and exciting.  There is a lot of passion in this department.  I’d especially like to thank David Nutall, Sean Gregory and Kate Jillings. Even though you may be unaware, I used your field data from Field School to help complete my dataset, which undoubtedly made my project better.  Also to Barry Penner, to whom I could turn to for help and ideas.  Thanks to NSERC (SURE AWARD) and DuMoulin Black LLP for their scholarship funding and award money.  It definitely helped to lighten the stress, allowing me to dedicate more time to my thesis.  And last but definitely not least, I’d like to thank my wife Tara, who has been my driving force, my inspiration and my compass throughout my educational endeavors.  Without you I’d be lost.   iv  Table of Contents ABSTRACT	  .......................................................................................................................................	  iii	  LIST	  OF	  FIGURES	  ...........................................................................................................................	  vi	  LIST	  OF	  PLATES	  .............................................................................................................................	  vi	  1.	  INTRODUCTION	  ..........................................................................................................................	  1	  2.	  GEOLOGIC	  SETTING	  ...................................................................................................................	  1	  3.	  PREVIOUS	  WORK	  ........................................................................................................................	  4	  4.	  METHODOLOGY	  .......................................................................................................................	  10	  4.1	  SAMPLE	  COLLECTION	  AND	  PROCESSING	  ................................................................................	  10	  4.2	  MAPPING	  AND	  OUTCROP	  DRAWING	  ........................................................................................	  11	  4.3	  STRUCTURAL	  MEASUREMENT	  ANALYSIS	  ...............................................................................	  11	  4.4	  THIN	  SECTION	  PREPARATION	  ...................................................................................................	  11	  4.5	  THIN	  SECTION	  PETROGRAPHY	  ..................................................................................................	  11	  5.	  RESULTS	  .....................................................................................................................................	  12	  5.1.	  MT.	  KEOGAN	  INTRUSIVE	  COMPLEX	  .........................................................................................	  12	  5.1.1.	  Lithostratigraphic	  Description	  .............................................................................................	  21	  5.1.2.	  Structure	  .......................................................................................................................................	  23	  5.2.	  GREEN	  LAKE	  METASEDIMENTARY	  COMPLEX	  ......................................................................	  25	  5.2.1.	  Lithostratigraphic	  Description	  .............................................................................................	  34	  5.2.2.	  Structure	  .......................................................................................................................................	  34	  6.	  INTERPRETATION	  AND	  DISCUSSION	  ................................................................................	  41	  6.1	  FORMATION	  OF	  THE	  MT.	  KEOGAN	  INTRUSIVE	  COMPLEX	  ................................................	  41	  6.2	  GREEN	  LAKE	  METASEDIMENTARY	  COMPLEX	  –	  PROTOLITHS	  AND	  PRE-­‐MYLONITE	  METAMORPHISM	  ...................................................................................................................................	  46	  6.3	  STRUCTURAL	  DEVELOPMENT	  OF	  THE	  OVSZ	  .........................................................................	  47	  6.4	  TEMPERATURE	  CONDITIONS	  DURING	  DEFORMATION	  .....................................................	  48	  6.5	  DISPLACEMENT	  ON	  DIEGO’S	  FAULT	  .........................................................................................	  51	  6.6	  RESULTS	  COMPARED	  TO	  PREVIOUS	  RESEARCH	  ..................................................................	  52	  6.7	  TECTONIC	  SETTING	  AND	  DEVELOPMENT	  OF	  THE	  OVSZ	  ...................................................	  53	  7.	  CONCLUSION	  .............................................................................................................................	  55	  REFERENCES	  ..................................................................................................................................	  56	  APPENDIX	  #1:	  Field	  and	  Lab	  Data	  ..........................................................................................	  59	  APPENDIX	  #2:	  Rock	  slab	  photos	  .............................................................................................	  60	  APPENDIX	  #3:	  Thin	  section	  pictures	  .....................................................................................	  61	      v  LIST OF FIGURES Figure 1. Regional map of field area………………………………………………………….2 Figure 2. Schematic middle Jurassic reconstruction…………………………………………..3 Figure 3. Ross and Christie’s structural cross section………………………………………...6 Figure 4. Tempelman-Kluit and Parkinson’s cross-section and displacement map…………..7 Figure 5. Air photo of field area showing fault lines………...………………………………..9 Figure 6. Outcrop maps of structural elements…………………………………………...13-19 Figure 7. Field pictures of the Mt. Keogan field area showing approximate dip…………....20 Figure 8. Mafic and felsic schlieren………………………………………………………….22 Figure 9. Fractured garnets……..……………………………………………………………22 Figure 10. Dynamically recrystallized feldspar ..……………………………………………24 Figure 11. Biotite replaced by chlorite…….………………………………………………...26 Figure 12. Stereonet analyses of major outcrops…………………………………………27-29 Figure 13. Elongation lineations in hand sample…………………………………………….30 Figure 14. Biotite and hornblende laths defining foliation…………………………………..30 Figure 15. S-C mylonitic fabric……………………………………………………………...31 Figure 16. Shear sense indicators…………………………………………………………….32 Figure 17. Fold axes oriented sub-parallel to foliation………………………………………33 Figure 18. Original bedding/compressional fabrics………………………………………….35 Figure 19. Zircons……………………………………………………………………………35 Figure 20. Sericite alteration along twinning planes ……………………...………………...36 Figure 21. Sericite alteration of feldspars……………………………………………………36  Figure 22. C-axis orientations……………………...………………………………………...38 Figure 23. Quartz and carbonate veinlets………………….…………………………….......39 Figure 24. Dynamically recrystallized quartz defining (Lm) ………………………………..39 Figure 25. Steeply dipping S0/S1……………………………………………………………..40 Figure 26. Isoclinal recumbent folds……….………………………………………………..42 Figure 27. Refolded folds and vertical mylonite fabric…………….………………………..43 Figure 28. Sheath folds…………….………………………………………………………...44 Figure 29. Variation in grain size……………..……………………………………………..45 Figure 30. Folded granitic sheets………...…………………………………………………..49 Figure 31. Schematic cross section of field area…….……………………………………….50 Figure 32. Mica fish………………………………………………………………………….54  LIST OF PLATES Plate 1.  Geologic map of field area……………………………………………...in back covervi  1. INTRODUCTION A section of the Okanagan Valley shear zone (OVsz) is exposed west of Vaseaux Lake in the southern Okanagan Valley, 2 km north of the town of Oliver, British Columbia (Figure 1).  This area is mapped by 3rd year geology students at The University of British Columbia (UBC Vancouver). In order to improve the geologic framework for a student mapping exercise, the purpose of this thesis is to better define the lithostratigraphy, internal structural geometry, and gross kinematic evolution of the OVsz in the field area.  The results of this study will be used to improve the geological framework for future UBC mapping exercises across the OVsz. Reconnaissance field mapping of the field area resulted in the collection of oriented samples and representative samples of all the major lithological units. Detailed structural mapping of selected outcrops representative of the internal geometry of the OVsz was completed.  Petrographic descriptions and microstructural analysis of oriented thin sections was carried out to characterize the kinematic evolution of the OVsz and construct structural cross section representative of the subsurface.    2. GEOLOGIC SETTING  The OVsz is located within the Shuswap metamorphic complex (SMC) in the Omineca belt, which formed when the Intermontane belt accreted to the western margin of North American craton during the Late Permian to Early Jurassic time (Monger et al., 1982; Armstrong et al., 1991; Carr, 1991; Eyal et al., 2006) (Figure 2).   Subsequent accretion of the Insular belt and westward underthrusting of the North American craton caused widespread metamorphism and crustal thickening in excess of 50-60km (Monger et al., 1982; Coney and Harms, 1984; Carr, 1991; Bardoux and Mareschal, 1994).  During the Paleocene, extensional collapse began as a result of the change in convergence of the eastward-subducting Kula plate (oceanic) as it evolved from a transpressional to transtensional environment (Ewing, 1980; Engebretson et al., 1984; Bardoux and Mareschal, 1994; Brown et al., 2012).  This extensional collapse was facilitated by north-south striking, normal sense, low-angle detachment faults that exhumed mid-crustal rocks exposing the associated shear  1FieldareaFigure 1: Simplified geologic map of the Shuswap metamorphic complex showing the location of this study’s field area.  Figure is adapted from Johnson (2006) and Brown et al. (2012). Abbreviations: ANT - Adams Lake-North Thompson fault; CRF - Columbia River fault; FF - Fraser fault; K - Kettle-River-Grand Forks Dome; M - Malton gneiss dome; MD - Monashee decollement; MO - Monashee gneiss dome; OER - Okanagan-Eagle River; Ok - Okanagan complex; OkD - Okanagan Dome; OVF - Okanagan Valley fault (OVdf in this study); P - Priest River complex; RG - Republic graben; SRMT - Southern Rocky Mountain trench; T - Toroda Creek graben; V - Valhalla Dome; Inset: Simplified map of the southern Canadian Cordillera showing morphogeologic belts.  The field area is located within the Shuswap metamorphic complex (SMC).BC2Figure 2: Schematic middle Jurassic reconstruction of the miogeosyncline of the western North American craton.  This shows the accretion of the consecutive terranes that gave rise to the thickened crustal welt that eventually collapsed to form the OVsz and OVdf.  Abbreviations: CC - Cache Creek terrane; Ins - Insular terranes; ST - Stikine terrane (major constituent of the Intermontane belt).  Modified from Nelson and Colrpon (2007). 3  zones (Ewing, 1980; Okulitch, 1984; Johnson and Brown, 1996).  The OVsz is a westward shallow-dipping crustal detachment that delineates the western boundary of the exposed southern Shuswap metamorphic complex (Tempelman-Kluit and Parkinson, 1986; Carr, 1995; Johnson and Brown, 1996).  On the western margin of the Shuswap metamorphic complex, the OVsz is part of a 450 km-long en echelon fault system described by Johnson and Brown (1996) and Okulitch (2004) as the Okanagan Valley fault system. In the study area, the Okanagan Valley detachment fault (OVdf) is the boundary between the Shuswap metamorphic complex in the footwall and the hanging wall rocks of the White Lake basin, which includes the Eocene aged Marron Group and the White Lake sedimentary suite (Parrish et al., 1988; Eyal et al., 2006; Glombick et al., 2006; Brown et al., 2012; Twomey, 2014).  The OVdf has an estimated dip of 20° to the northwest (Tempelman-Kluit and Parkinson, 1989; Bardoux and Mareschal, 1994). The OVsz is an approximately 1-2 km thick mylonite zone in the immediate footwall to the OVdf (Tempelman-Kluit and Parkinson, 1986).  It comprises ductilely deformed intrusive and metamorphic rocks characterized by a prominent shallow dipping foliation (Brown et al., 2012; Twomey, 2014).  The hanging wall rocks are local Eocene volcanic and sedimentary rocks (Tempelman-Kluit and Parkinson, 1986; Bardoux and Mareschal, 1994; Brown et al, 2012; Twomey, 2014), but also contain large breccia units containing numerous clasts of mylonitic rocks from the OVsz.  The total horizontal displacement across the OVsz and OVdf is estimated to be as much as 90 km (Tempelman-Kluit and Parkinson, 1986; Johnson and Brown, 1996; Brown et al., 2012).  Recent geochronology studies suggest that displacement occurred in the Eocene (Brown et al, 2012).  3. PREVIOUS WORK   The first major research project done in the immediate field area west of Vaseaux Lake was done by Ross and Christie (1978).  Their studies were conducted prior to recognition of the detachment fault and its associated shear zone and therefore their interpretation has been drastically changed with newer studies. They defined three major phases of deformation.  Phase 1, consists of recumbent, isoclinal fold system that verges to the west with fold axes plunging shallowly to the north. Folding was accompanied by upper 4  greenschist-facies metamorphism.  Phase 2, consists of a recumbent, tight fold system with axial surfaces dipping to the north with northwest and southeast trending, shallowly plunging fold axes. Metamorphism during this folding event is thought to have reached middle amphibolite-facies and was associated with extreme ductile deformation.  Phase 3 refolds all earlier structures about axial surfaces dipping to the southwest and northwest with southeast trending, shallowly plunging fold axes. This deformation is thought to have been associated with lower amphibolite-facies metamorphism. The timing of deformation is suggested to be have begun before the Permo-Triassic, with Phase 2 occurring during the Permo-Triassic and Phase 3 during the Middle Jurassic, coinciding with the beginning of the Columbia Orogeny (Ross and Christie, 1978).  Ross and Christie (1978) also suggest that there are two younger phases of deformation comprised of open, rounded limbs and minor fold axes trending north-south and east-west (Figure 3).    Tempelman-Kluit and Parkinson (1986) suggested that the Okanagan Valley follows an Eocene age crustal shear zone (equivalent to the OVsz of the present study) that dips gently to the west (Figure 4a).  They noted that Cenozoic extension features seen in the Shuswap metamorphic complex overprint Mesozoic compressional fabrics representing the collision between North America and the Intermontane belt (Figure 2).   The metamorphic field-gradient seen in the rocks of the OVsz allows for interpretation of the depth of formation (Tempelman-Kluit and Parkinson, 1986).  Assuming a 25°C/km gradient (Yardley, 1989), the amphibolite-facies section of the OVsz formed at 550° and 25 km depth, the upper greenschist-facies section formed at 250°C and 15 km depth and the lower greenschist-facies section near the top formed at 250°C and 10km depth (Twomey, 2014).  This gradient directly corresponds with a shear zone that has risen from mid-crust to shallower levels during the extension process (Tempelman-Kluit and Parkinson, 1989).  Through analysis of displaced rocks of the Eocene Marron Group and radiometric ages of the strained gneisses, relative timing of displacement was established between 52 and 47 Ma (Tempelman-Kluit and Parkinson, 1989; Johnson, 2006).  They also found that the Coryell syenite found in the footwall were chemically comparable to the Marron Group volcanic rocks found in the hanging wall and inferred that it was the plutonic root for the volcanic system.  Using this relationship as a piercing point, Tempelman-Kluit and Parkinson (1989) estimated a horizontal displacement of approximately 90 km on the OVsz (Figure 4b). 5B B’’B’C C’’C’Mt. KeoganFigure 3: Structural cross sections through Mt. Keogan and Vaseaux Lake area along lines B-B” and C-C” taken from Ross and Christie (1978, figure 2).  Segments B-B’ and C-C’ cross this study’s field area and are shown on Plate 1 for reference.6b)a)Figure 4: a) East-west cross section 18 km south of Pentiction, showing inferred relations of upper plate detachment structures to lower plate gneisses (Taken from Tempelman-Kluit and Parkinson, 1986, figure 2); b) Map taken from Tempelman-Kluit and Parkinson (1986, figure 5) shows their estimates of extension on the OVdf.  Extension was calculated by separation of upper- and lower-plate rocks thought to have been superposed before detachment.  Their average estimated displacement is 90 km. Direction from root to detached top of each case (long arrows) coincides with lineation in detachment-zone gneiss (short arrows) (Tempelman-Kluit and Parkinson, 1986).  7   Brown et al. (2012) researched the magnitude of extension and the age of the protoliths along with the development of the Okanagan gneiss, part of the Shuswap metamorphic complex, as described by Tempelman-Kluit and Parkinson (1989).  Older studies differ on the amount of extension based on the their location along the OVsz, varying from 0-12 km near Vernon (Glombick el al., 2006) to 30-90 km north and south along Okanagan Valley (Tempelman-Kluit and Parkinson, 1986; Parrish et al., 1988; Johnson and Brown, 1996).  Brown et al. (2012) infer that the Shuswap metamorphic complex is Mesozoic and the mafic sheets that have intruded it are Middle Jurassic.  Exhumation of the Okanagan gneiss from a minimum of 20 km depth and along the OVsz occurred during the Eocene (Brown et al., 2012).  Using that depth and approximate dip angle of 20° for the detachment fault, Brown et al.’s (2012) displacement estimation is 64-89 km.   Twomey (2014) researched a section of the OVsz to the north of Penticton.  His work analyzed the c-axis orientations of the quartz mylonite fabric.  He described three separate domains within the OVsz, with an overall thickness of approximately 1.5 km.  Domain 1, along the OVdf, consists of brittle features overprinting cataclasite and grading downward into ultramylonite.  Domain 2 includes felsic syn-tectonic intrusions located within moderately mylonitized greenschist- to amphibolite-facies ortho- and paragneisses.  Domain 3, at the base of the shear zone, is moderately to weakly foliated ortho- and paragneiss interlayered with weakly or non-deformed plutonic rocks.  Through the analysis of quartz microstructures and c-axis fabrics, Twomey (2014) infers deformation temperatures that increase from <280° near the OVdf to upwards of 650°C at the base of the OVsz.  The consistent shear sense from analysis of macro- and microstructural shear sense indicators is top-to-the-west-north-west and involves non-coaxial deformation (Twomey, 2014).  High angle normal faults occur perpendicular to the direction of extension and are attributed to late stage, rapid exhumation within the brittle zone (Brown et al., 2012; Twomey, 2014).  They can be traced in air photos (Figure 5) and in changes in elevation of the land surface (Plate 1). Tempelman-Kluit and Parkinson (1986) characterized the OVsz as a brittle-ductile shear zone, and referred to it as the Okanagan crustal shear, whereas Parrish et al. (1988) referred to it as the Okanagan Valley fault.  Most recently, Brown et al. (2010) renamed the structure as the Okanagan Valley shear zone.  All three studies claimed that exhumation of  8Figure 5: Airphoto taken from Google Earth of the field area, normal faults parallel to the OVdf (green) are outlined in red.Diego’s FaultGreen LakeVaseaux LakeMt. KeoganOVdf9  the Shuswap metamorphic complex was a classic example of gravitational collapse caused by overthickening of the crust (Tempelman-Kluit and Parkinson, 1986; Parrish et al., 1988; Eyal et al., 2006; Brown et al, 2012).  In contrast, Glombick et al. (2006) suggested that the shear zone represents a channelized mid-crustal ductile flow zone. This interpretation was in part based on the presence of Eocene volcanic and sedimentary hanging wall rocks located on the eastern side of the supposed detachment fault.  Twomey (2014) suggests that Glombick et al. (2006) did not take into consideration the open, upright, km-scale corrugations found along the entire length of the OVsz.  Metamorphic core complexes commonly contain these corrugations (Singleton, 2012), which allow hanging wall rocks to appear on the footwall side of a shear zones as ‘islands’ in the keels of synforms (Tempelman-Kluit and Parkinson 1986; Eyal et al., 2006; Twomey, 2014).    4. METHODOLOGY  Eighteen days were spent in the field in May 2014.  The main goals of this field work were to: (1) undertake reconnaissance geological mapping of the study area; (2) Collect representative samples of all major lithological units for lithological and petrographic analysis; (3) undertake detailed structural mapping of a selection of outcrops representative of the internal geometry of the OVsz; and (4) collect representative oriented samples from these outcrops for detailed microstructural and mineralogical analysis.    4.1 SAMPLE COLLECTION AND PROCESSING Nine major outcrops showing extensive structural measurements where chosen to represent the major structure and mineralogy across the study area.  Representative oriented samples where collected from each outcrop using the strike and dip technique.  After labeling and orienting the samples, they were carefully chiseled out and collected.  Back in the lab each oriented sample was extensively cleaned and scrubbed to remove staining and lichen.  Some samples were soaked in bleach to assist in the cleaning process.  Each sample was re-oriented in a sand box and structural measurements where taken of any existing features, including fold axes, lineations, axial planes and bedding planes.  A database was created to store all relevant information (Appendix 1). 10  4.2 MAPPING AND OUTCROP DRAWING Daily traverses were planned based on ease of access from the existing trail network.  One week of reconnaissance mapping helped locate and decide which representative outcrops to use (refer to Plate 1).   Once these were chosen, extensive mapping and drawing of the outcrops was completed.  The pace and compass technique was used to accurately map the extent of each outcrop.  Any structural measurements taken in the field were immediately placed in their geographical location on the outcrop maps.  4.3 STRUCTURAL MEASUREMENT ANALYSIS All the structural features found in the field were measured with Silva and Brunton compasses.   Most measurements where taken directly off of the existing formations, but some larger ones were estimated by standing at a distance and visually estimating the strike and dip, or using rulers to extend linear features.  4.4 THIN SECTION PREPARATION Profile planes of existing folds and vertical planes through any visible lineations were outlined on each rock.  Vertical planes were chosen as a standard through all lineation planes not only to aid with the visualization of cross sections but also because sense-of-shear can be exhibited by analyzing asymmetries in this plane (Lane, 1988).  Using large rocks saws, all the rocks were cut along appropriate planes and cut into slabs approximately 1 cm thick.  Each slab was analyzed and some structural measurements were taken again, including measurement of the cut plane itself.  Thin section locations where decided upon and drawn out on each slab with respect to horizontal, and then the slab faces were scanned (Appendix 2).  The slabs were then cut into thin section billets, appropriately labeled with sample number and orientation of the thin section face and then sent to Vancouver Petrography for thin section preparation.  4.5 THIN SECTION PETROGRAPHY  After receiving the thin sections back from Vancouver Petrography, each one was appropriately labeled and orientation directions were cross-referenced with slab pictures to ensure accuracy.  All thin sections were scanned using the Nikon Super Coolscan 9000 with 11  slide trays and both plain-polar (PPL) and cross-polar (XPL) lenses to create large images (Appendix 3).  Using the Nikon Eclipse E600 POL microscope equipped with a camera the mineralogy and microstructure of each thin section was assessed and described.  5. RESULTS  Across the entire field area all the rocks make up part of a mylonite zone, showing variable amounts of internal deformation.  All of the rocks have undergone ductile deformation and have all undergone some degree of syn-tectonic grain-size reduction via dynamic recrystallization.  From a textural perspective, they can all be variably classified as gneisses, schists and phyllonites.  The ratio of dynamically recrystallized matrix to relict porphyroclasts also enables them to be variable classified as protomylonite (0-50% matrix), mylonite (50-90% matrix), or ultramylonite (>90% matrix) reflecting both the rheological heterogeneity of the primary rock (largely a function of mineralogy), and the imposed strain rate as described by van der Pluijm and Marshak (2004).  There are two main rock complexes that make up the field area within the mylonite zone: (1) an intrusive complex; and (2) a complex of metasedimentary rocks representing the country rock surrounding the intrusive complex.  Descriptions of theses are given below.  Detailed maps of structural elements in selected outcrops across the field area were produced (Figure 6).  There is a large valley that crosscuts the field area and juxtaposes the two major complexes next to each other via this presumably steeply dipping normal fault, Diego’s Fault (refer to Plate 1).  From below Mt. Keogan and from the east side of Vaseaux Lake, the angle of the detachment fault plane can be estimated at approximately 20° towards the west (Figure 7).  5.1. MT. KEOGAN INTRUSIVE COMPLEX  Rocks of the Mt. Keogan intrusive complex crop out from the southern end of the field area near Covert Farms Winery to just north of Mt. Keogan (refer to Plate 1).  Outcrops range from steep cliff faces upwards of 40+ metres in elevation and hundreds of metres long to smaller rolling outcrops tens of metres long and are much more prevalent throughout the entire area.  Although many of the outcrops are largely covered in lichen and moss and extremely weathered by the elements, there are many locations where folding and banding  1221XMTZ1FXMTZ1EXMT1DXMT1CXMT1C34285735 42411048253364173775662 21162mFigure 6: Detailed maps of structural elements in selected outcrops across the field area.  Maps were constructed using pace and compass techniques.  Vertical separation is ignored owing to relatively small changes in elevations across outcrops (except Outcrop 2, indicated within Figure 6b.  a) Outcrop 1; b) Outcrop 2; c) Outcrop 3; d) Outcrop 4; e) Outcrop 5; f) Outcrop 6; g) Outcrop 7;  All locations can be referenced from the geologic map of the field area (Plate 1). *** Outcrops 8 and 9 is not mapped because they are small flatlying outcrops with only one oriented rock sample and limited structural measurements.a)13#2a#2b#2cXMT2B22m58158 27555224656523539462525192925252940193045152127172395831618776XMT2C12227b)14XMT3A1XMT3C1282639 262mc)152m181010415212716664231112618820XMT4A3XMT4A2XMT4A1d)162m62415399442242430XMT5A1e)17f)2m111111542215XMT6A3XMT6A218g)2mXMT7A115394151119Projected Okanagan Valley detachment fault plane~ 20ºFacing WHanging WallMarron GroupFoot WallGLmc & MKica) Figure 7: a) Picture of the field area from the east side of Vaseaux Lake.  Red dotted line shows estimated trace of OVdf.  Light green lines outline the granite sheet that also outcrops at Rattlesnake Lake (see Plate 1); b) Picture of Mt. Keogan peak taken from Rattlesnake Lake showing the projection of the OVdf sloping to the west at an estimated 20º dip.b)Facing N20  are readily visible.   Most outcrops have a visible planar to curviplanar mylonitic foliation defined by aligned biotite (±hornblende) and recrystallized quartz (±feldspar).   5.1.1. Lithostratigraphic Description The results of this study indicate that there are four main phases of igneous intrusion in the Mt. Keogan intrusive complex.  Two older intrusive phases are the most volumetrically extensive and crop out in the majority of the field area east of Diego’s Fault (refer to Plate 1). The first of these phases comprises centimetre-decimetre intercalated mafic and felsic schlieren that currently range in grain-size from gneiss (and augen gneiss) to schist and to a lesser degree phyllonite (Figure 8).  The mineralogy of this rock ranges from: a) felsic schlieren consisting of quartz (25-55%), plagioclase (15-40%) and k-feldspar (25-50%), biotite (5-25%) and garnet (<5%); and b) mafic schlieren that are much more biotite-rich (>50%). Accessory minerals include apatite, monazite and zircon. The garnets in both the mafic and felsic schlieren are heavily fractured (Figure 9).  The mineralogy of the schlieren indicates that they have a granitic to monzogranitic composition.  The size of the relict plagioclase and K-feldspar porphyroclasts (5-40mm) indicates that this intrusive phase was originally coarse grained.   The second, more mafic intrusive phase occurs in the northern part of the Mt. Keogan complex and is seen in detail at Outcrop #3 (Figure 6c).  It was also intruded relatively early, but there is no constraint on its timing relative to the granite schlieren.  The mafic intrusive layers are hornblende-rich and range from dark green to black in colour and are highly deformed.  There is not sufficient outcrop to know the extent of this rock type.  The mineralogy of this rock is quartz (5-20%), plagioclase (20-35%), k-feldspar (15-25%) and hornblende (10-30%).  Accessory minerals include epidote, titanite and zircon.  The mineralogy of this rock indicates that it is classified as a biotite-hornblende quartz-monzodiorite.  Finer-grained hornblende-bearing dioritic rocks are also exposed at the top of Mt. Keogan and are grouped in with this more mafic, monzodioritic intrusion, but this area was not studied in detail.  Owing to the extensive deformation and folding seen within the rocks of the Mt. Keogan intrusive complex, it is very difficult to assess whether or not there are more than two phases of large intrusive units.   21Figure 9: Abundant garnets fractured to varying degrees (sample MT1D).Figure 8: Centimetre scale intercalated mafic and felsic schlieren (sample MT5A1).a) b)1cm0.4 mm0.4 mm22  The third intrusive phase recognized in the Mt. Keogan intrusive complex comprises granitic sheets.  These centimetre-decimetre sheets have intruded both of the previously described phases and occur sub-parallel to their layering.  Owing to the deformation and folding, it is difficult to correlate any of these granite sheets over any large distances.  The mineralogy of these granitic sheets is quartz (25-55%), plagioclase (15-35%) and k-feldspar (20-45%) and biotite (5-15%).   The layers can be distinguished from the schlieren by their larger scale thickness (tens of centimetres to metres) and that they are relatively biotite/hornblende-poor.   In the area around Rattlesnake Lake and into the Vaseaux Lake cliffs, there is a very large intrusion (10s of metres) of very coarse grained, leucocratic, garnet (<1%) and biotite (<5%) granite that outcrops through the centre of the Mt. Keogan intrusive complex at Outcrop 8 (sample WL14-18).  This intrusion is mapped as a separate phase due to its lateral continuity and has been named the Rattlesnake Lake granite (refer to Plate 1). This intrusion is much coarser grained than the surrounding rocks and extends out into the Vaseaux cliffs as a long, thick sill (Figure 7).  It is also much less deformed and mylonitized than the surrounding rocks and represents a large-scale later syn-tectonic sill or dyke.  The fourth intrusive phase crosscuts the entire field area.  They are post- to syn-kinematic centimetre-decimetre leucogranitic dykes showing varying degrees of deformation and penetrative fabric.  This phase is separated from the granitic sheets phase because of the late intrusive nature the dykes, they have no preferred orientation, whereas the granitic sheets were intruded parallel to layering.   There are isolated 15-20 metre outcrops of marble that lie sub-parallel to foliation that cannot be traced from outcrop to outcrop.  The small lenticular nature of these outcrops is believed to represent slivers of country rock entrained within the intrusive rocks and have been rotated into the foliation plane during deformation.   5.1.2. Structure The rocks of the Mt. Keogan intrusive complex have undergone varying degrees of dynamic recrystallization.  Quartz and biotite are the most recrystallized mineral phases, but in the more highly deformed rocks plagioclase and K-feldspar can be extensively recrystallized (Figure 10). Proto- to ultra-mylonitic fabrics overprint the various intrusive  23XPLfeldspar284Figure 10: Dynamically recrystallized porphyroclast of plagioclase (sample MT7A1).  Red lines show a top-down-to-the-west shear sense.1mm24  phases.  Minor amounts of regional hydration and retrograde metamorphism are seen in biotite grains that are altered to chlorite and titanium bearing oxides (Figure 11).   K-feldspar and plagioclase tend to be the least recrystallized phase and commonly forms relict augen porphyroclasts in all the intrusive phases. Rarely, K-feldspar and plagioclase augen exhibit evidence of dynamic recrystallization (Figure 10), but do not have strong core mantle textures. The dominant linear fabric is penetrative and defined by the dynamic recrystallization of quartz grain rods (Lm) plunging 5-25° towards 290° (Figure 12b-i).  The mylonite foliation (Sm) is sub-parallel to the axial planes of the folding of banded schlieren that range from 285/7°NE to 105/7°SW (Figure 12b-i).  Elongation/stretching lineations (Lm) are the most prominent linear fabric elements in outcrops and are predominantly exhibited by quartz rods, with minor elongation exhibited by plagioclase and K-feldspar (Lister and Price, 1977) (Figure 13).  In thin section biotite and hornblende laths are preferentially rotated into the stretch direction (Figure 14).   S-C fabrics are developed in the biotite rich layers that anastomose around quartz and feldspar porphyroclasts. C-planes are represented by biotite and extremely recrystallized quartz or feldspar.  The S-planes are defined by flattened and recrystallized porphyroclasts of feldspar and ribbons of recrystallized quartz (Figure 15).  Porphyroclasts showing σ-type shear sense indicators as described by Passchier and Simpson (1986) and fractured grains showing synthetic movement (Simpson and Schmid, 1983) all are consistent with top-down-to-the-west-northwest shear sense (sinistral looking north-north-east) (Figure 16).  In the Mt. Keogan intrusive complex the folds are tight, isoclinal recumbent and folding banded schlieren or small granitic sheets around Fm (Figure 12a-iii-viii).   Some of the granitic sheets are intruded later in the deformation history and show open folds with axial planes sub-parallel to Sm.  The majority of fold axes found at outcrop or hand sample scale are oriented sub-parallel to Lm, approximate plunging 8° towards 290° (Figure 17 and Figure 12b-i).    5.2. GREEN LAKE METASEDIMENTARY COMPLEX  Rocks of the Green Lake metasedimentary complex crop out to the northwest of Diego’s Fault (refer to Plate 1).  All major outcrops are larger in vertical and horizontal scale compared to the Mt. Keogan intrusive complex, making many of them harder to access.  The outcrops are heavily weathered as well as lichen and moss covered.  Some outcrops show  250.5mmPPL163PPL026a)Figure 11: Biotite replacement by chlorite and minor amounts of oxides from retrograde metamorphism of the rock in the OVsz:  a) sample MT4A2i; b) sample MT3A-melano.b)26N Na)N NNii)Figure 12: a) Structural data presented on lower-hemisphere equal-area stereonets i) Outcrop 1; ii) Outcrop 2; iii) Outcrop 3; iv) Outcrop 4; v) Outcrop 5; vi) Outcrop 6; vii) Outcrop 7; viii) Outcrop 8; b) All structural data from: i) Mt Keogan intrusive complex and; ii) Green Lake metamorphic complex.  i)iii) LegendMineral elongation lineationsFold axes (F2)Foliation planes (Sm/S2)Foliation planes (S0/S1)Contour of poles to axial planesof F2 (GLmc) and Fm (MKic) 27N Niv)N NNv)vi) N28N Nb)N Ni)ii)N Nvii)29Figure 13: Elongation lineations seen at the outcrop and hand sample scale.  Lineations are best defined by stretched quartz, k-feldspar and plagioclase grains.Figure 14: Biotite and hornblende laths defining the S1 plane and parallel to the bedding plane (S0): a) sample MT2B2; b) sample MT3A-melano.a) PPL338b) PPL163S2S0/S10.5 mm0.5 mm30Figure 15: S-C mylonite fabrics seen in thin sections of Mt. Keogan intrusive complex.  S-planes defined by  flattened and recrystallized porphyroclasts feldspars and ribbons of quartz, C-planes are represented by biotite and extremely recrystallized quartz or feldspar: a) sample MT3A-melano; b) sample MT4A2i163120a)b)XPLXPLSCSC31Figure 16: σ-type porphyroclasts of feldspar and fractured grains as described by Passchier and Simpson (1986) and Simpson and Schmid (1983): a) feldspar porphyoclast with tails of recrystallized quartz (sample MT4A2i); b) feldspar porphyroclast with tails of biotite and recrystallized quartz (sample MT5A1).  c) fractured feldspar grain with tails of recrystallized quartz (sample MT4A3).  Red lines show the trace of the structural fabric and the associated shear sense.120XPL XPLa) b)105102XPLc)1 mm1 mm 0.5 mm32Figure 17: Elongation lineations are oriented sub-parallel to fold axes measured in the field and from oriented samples (sample MT5A1).XPL105LineationFold Axis Trace0.5 cm33  centimeter to metre scale recumbent folds, but the majority of them are fractured and eroded into large blocks.  Closer to the OVdf the rocks become for brittlely fractured and are much greener in colour.    5.2.1. Lithostratigraphic Description  The Green Lake metasedimentary complex is a package of metamorphosed volcaniclastic and sedimentary rocks that represent the country rock to the Mt. Keogan intrusive complex. The majority of the rocks consist of intercalated layers of millimetre-centimetre scale leucocratic and melanocratic material that represents original sedimentary bedding (S0) (Figure 18).  The leucocratic bands are extremely quartz-rich (>90%) with accessory minerals plagioclase, K-feldspar, biotite, hornblende, garnet, epidote, carbonate, white mica and opaques.  The melanocratic bands are more biotite- and hornblende-rich.  Both the leucocratic and melanocratic bands are fine grained (<1mm) owing to the intense degree of mylonitization and there are many porphyroclasts of feldspar, hornblende and titanite.  The entire rock contains abundant detrital zircons, many of which are very rounded (Figure 19).  The assemblage of epidote, chlorite, hornblende and garnet, indicates peak metamorphism has reached upper greenschist- to amphibolite-facies.  The calcium-alumina signature signifies a reworked volcaniclastic deposit.  Although primary muscovite and chlorite are absent, secondary sericite and chlorite occur along fracture planes (Glombick et al., 2006) and along twinning planes (Figure 20).   Minor biotite replacement by chlorite and minor oxides from retrograde metamorphism (Figure 10) and the sericitization of feldspars (Johnson et al., 1999; Glombick et al., 2006; Johnson, 2006) (Figure 21) is syn- to post-kinematic and most likely represents an introduction of fluids to regions being closer to the OVdf during and after brittle deformation.  The alteration becomes more intense closer to the OVdf as access to fluids was increased.  5.2.2. Structure   The Green Lake metasedimentary complex is intensely ductilely deformed with a well-formed mylonite to ultramylonite foliation (Sm) variably oriented from 290/10° to 110/10°.  The foliation is defined by strong preferred crystallographic orientation of the fine- 34Figure 18: Original bedding (S0) and S1 foliation plane, sub-parallel to each other within rocks of the GLmc (sample MT2B2).338PPLOriginal bedding S0Biotite S1Figure 19: Zircons are found in the majority of rocks in the field area, usually (but not exclu-sively) within the leucocratic bands: a) igneous zircons found in rocks of the MKic; b) abun-dant detrital zircons found in rocks of the GLmc.PPL PPLa) b)0.5cm0.5mm0.5mm35Figure 21: Serecite alteration of feldspars: a) closer to the OVdf alteration is more intense (sample MT1D); b) further away alteration is weaker (sample MT4A2i).XPL XPLa) b)Figure 20:  sericite alteration along twinning planes of feldspars a) sample MT4A2i; b) sample MT4A3.XPLa) XPLb)0.5 mm1 mm0.2 mm1 mm36  grained quartz, which is apparent when viewing samples under polarized light using a gypsum plate (Figure 22).  This preferred orientation of quartz does not typically result in a planar fabric visible in hand specimen and as such is really only visible in thin section.  Such a strong preferred crystallographic orientation of quartz is a product of extensive dynamic recrystallization.  The lack of quartz porphyroclasts makes it difficult to know if there was any extensive reduction in grain size associated with this recrystallization as the rock may have originally had a fine grain size.   In hand samples, stretching lineations are not readily observed, which may reflect the fine-grained nature of the rocks and the lack of large recrystallized porphyroclasts. Biotite grains have been rotated sub-parallel to the bedding plane (S0) and represent the S1 foliation (Figure 14).  Both S0 and S1 are folded around F2 which is axial planar to the regional mylonitic foliation.  There are many cross cutting veins of quartz and carbonate that remain undeformed (Figure 23).  The S2 foliation is not readily visible in hand specimen as there was either: a) insufficient mica to allow the development of a crenulation cleavage; or b) the strain rate may have been to high for progressive crenulation to occur and strain was taken up by intracrystalline strain in quartz located in the fold limbs. Quartz is extensively recrystallized and predominantly responsible for the strongly developed mylonitic fabric.  Rodding and streaking of quartz and feldspars along with the alignment of amphibole laths create lineations (Lm) seen in thin sections (Figure 24).  At the outcrop level there are areas of predominantly steep S0/S1 overprinted by shallowly dipping folds and mylonitic foliation (Figure 25).  Undulose extinction in quartz and feldspars is prevalent as well as sub-grain development and undulatory grain boundaries, which are all indicative of dynamic recrystallization (Glombick et al., 2006).  Plagioclase, K-feldspar, epidote and hornblende are all relatively stable at the temperature and pressure of deformation and the majority of the deformation is taken up by the quartz, owing to the quartz-rich nature of the rock.  As is the case with the Mt. Keogan intrusive complex, the visible folds have axial planes that are sub-horizontal and are sub-parallel to the enveloping mylonitic surface (Sm).  Although Sm is not visible in outcrops or hand specimens, the folds are tightly folded where S0/S1 is almost completely transposed by F2 making them sub-parallel to S2.   The long limbs of these folds are large enough to show areas of sub-horizontal bedding creating areas with large planar features.  The axial planar cleavage (S2) of recumbent, isoclinal folds found from  37Figure 22: C-axis orientations of dynamically recrystallized quartz grains.  Similarity in colours indicates that the orientations are sub-parallel to each other and rotated towards direc-tion of extension creating the mylonitic fabric (Lm). XPL + Gypsum Plate1 mm38Figure 23: a) veinlets of quartz and seen in thin sections of rocks of GLmc and MKic (sample MT1D);  b) veinlets of carbonate seen in outcrops of GLmc (sample MT1D) .XPL XPLa) b)Figure 24: dynamically recrystallized quartz elongated to form mylonite lineation (Lm) (red lines): a) sample MT1D; b) sample MT3A-melano.1mm 1mma) b)0.4 mm0.5 mm16310839Figure 25: a) steep S0/S1 foliations at the outcrop scale (Outcrop 2c); b) S0/S1 foliations being folded around F2 (Outcrop 2b).a) b)1cm 1cmS0/S1S2/Sm40  outcrop to thin section scale (Figure 26) are sub-parallel to the mylonite foliation (Sm) which is only observed in thin section and has the same orientation as the sub-horizontal mylonitic fabric observed in the Mt. Keogan intrusive complex.  The one exception is at Outcrop 9 (sample MT9A1), where the mylonitic fabric observed in thin section is sub-vertical.  The Sm foliation is axial planar to vertical S2 folds of S0/S1 (Figure 27).  This is the only locality where this vertical geometry was observed.  There are three possible explanations: a) This is really a zone of vertical Sm foliations as mylonitic foliations can be folded and refolded with axial surfaces parallel to the regional mylonitic fabric (Lane, 1988; Bell and Hammond, 2011); b) the rocks have been rotated as rigid blocks within the OVdf and are no longer in the original orientation that Sm formed; or c) there are numerous large fallen blocks of rock on the valley slopes and perhaps the outcrop is not in place, and may represent a large fallen block that has been subsequently buried and exhumed. Most of the fold axes are oriented similar to the stretching lineation (Lm) at approximately 10° towards 290°, although a few are oriented almost perpendicular to the stretching lineation towards 020° (Figure 12a-ii).  This is observed at Outcrop 2 where sub-vertical S0/S1 is weakly overprinted by S2, and when observed at the microscope scale, the quartz shows a strong preferred orientation Lm.  Some fold axes have been rotated from the more north-north-east orientation towards the typical west-north-west direction creating sheath folds that are commonly found in shear zones (Johnson et al., 1999) (Figure 28).     6. INTERPRETATION AND DISCUSSION 6.1 FORMATION OF THE MT. KEOGAN INTRUSIVE COMPLEX  The Mt. Keogan intrusive complex is large enough that it extends past the bounds of the field area.  There are multiple phases interpreted to be a monzodioritic to granitic intrusive complex with later intrusion of granitic phases. The entire Mt. Keogan intrusive complex is relatively coarse grained, but there are areas of higher strain where the quartz and biotite layers can be classified as phyllonites (Figure 29).  The presence of slivers of white marble is believed to be representative slivers of the host rock and related to the rocks of the Green Lake metasedimentary complex.  Previous dating by Brown et al. (2012) suggests that the large granitic sheets within the field area are of Eocene age, and that the earlier, more  41Figure 26: Isoclinal recumbent folds seen in outcrops throughout the field area: a) folds of leucocratic and melanocratic schlieren in MKic showing the vertical repetative nature of the folds (folds are oblique to rock surface and plunge towards the left); b) tight,  folds of leuco-cratic and melanocratic schlieren in MKic that show minor shearing and refolding seen at Outcrop 4; c) folds of S0/S1 in GLmc d) folds seen at Outcrop 1 (GLmc) (oriented sample MT1C);  e) fold of of S0/S1 seen at Outcrop 2 (GLmc),  parasitic folds surround the larger hinge; f)  thin section scale recumbent fold of of S0/S1 (GLmc) (sample MT1D).S0/S110cmSm2cm1mmS0/S1S2/Sm198Sm2cmS0/S12cm10cmS0/S1e) f)c) d)b)a)XPLS2/SmS2/SmS2/Sm42Figure 27: Rocks at Outcrop 9 have: a) refolded folds, either representative of relict deforma-tion or part of the progressive deformation along the shear zone (ignore black lines); and b) a sub-vertical mylonitic fabric (red lines).  The outcrop is possibly a large clast of shear zone rock that has been placed in the valley near Green Lake, which would help to explain the verti-cal orientation of the mylonite fabric. 041a) b)1cm 2mm43Figure 28: Sheath fold found in a hand sample from Outcrop 1.  F2 has been rotated into the direction of shear (facing E-SE).  Solid red line shows the original bedding plane, while the dotted red line shows two F2  fold hinges (sample MTZ1E). 2cmS0/S1S2/Sm F2F2F244Figure 29: Picture of the variation in grain size in one rock type (sample MT7A1).  The coarser grainer leucocratic band is a centimetre scale granite sheet, the fine grained melanocratic band is a biotite, quartz phyllonite.2cm45  deformed monzodioritic to granitic intrusive rocks are likely Cretaceous to Eocene in age. These intrusions may be related to the extensional collapse of the thickened crustal welt as decompression melting was initiated, although some may be relict from the collisionary event.  The heat from the intrusions could have also facilitated movement along the OVdf, leading to a positive feedback cycle (decompression creates melt and melt facilitates movement).   The OVsz has deformed the entire Mt. Keogan intrusive complex.  The three main intrusive phases are old enough to be extensively deformed, possibly being emplaced before or early during initiation of the shear zone.  The lesser granitic sheets and dykes have seen much less deformation and most likely intruded closer to the conclusion of the movement along the OVdf.    6.2 GREEN LAKE METASEDIMENTARY COMPLEX – PROTOLITHS AND PRE-MYLONITE METAMORPHISM  The Green Lake metasedimentary complex has been previously mapped as a sequence of interlayered sedimentary rocks classified as semipelitic granulites (Ross and Christie, 1978) that likely represent the host rock into which the Mt. Keogan intrusive complex was intruded (Brown et al., 2012).  Although the rocks are sedimentary in nature, they were metamorphosed prior to extension and subsequent intrusion of the Mt. Keogan intrusive complex.  The sediments are suggested to be part of the miogeosyncline of the western edge of the North American craton (Nelson and Colpron, 2007) (Figure 2).  The occurrence of plagioclase and calcium-rich minerals along with detrital zircons infers a volcaniclastic depositional environment and the abundance of quartz infers that a fair amount of terrigenous components were also incorporated into the depositional environment.  The presence of minor amounts of biotite also represents a component of terrigenous input as clays would have also been deposited into the system.  Owing to the dating of Brown et al. (2014), the relative age of the country rock can be estimated to be pre-Cretaceous.     Primary epidote, hornblende, plagioclase, quartz and garnet establish the peak metamorphic grade at upper greenschist- to amphibolite-facies.  The temperature and pressure gradients agree with levels needed to dynamically recrystallize K-feldspar (approximately 500-600°C).  There are minor amounts of secondary chlorite observed, but 46  not enough to infer that major amount of water were introduced into the system during deformation.      6.3 STRUCTURAL DEVELOPMENT OF THE OVSZ The entire field area consists of a large shear zone gently dipping to the west (Tempelman-Kluit and Parkinson, 1986) and overprinting the two main rock types.  In the country rock (GLmc), original bedding and compressional fabrics S0/S1 are overprinted by a tightly folded, recumbent, isoclinal series of folds (F2).  Elongation lineations are produced by strongly non-coaxial plastic shear, which also creates recumbent isoclinal folds (Figure 26) and sheath folds (Figure 28).  Mineral aggregates, elongate feldspar grains and quartz rodding and ribbons define elongation lineations.  The dynamically recrystallized quartz shows a very strong crystallographic orientation owing to their c-axes being rotated towards the stretching direction (Figure 22).  In some places the rocks can be classified as ultramylonite to phyllonite.   Moving from structurally lower to higher in the OVsz, matrix grain size and the proportion and size of augen generally decrease.   Pervasive millimetre-scale chlorite, quartz and calcite veinlets cut through the rocks over the entire field area (Figure 23).  The OVsz most likely developed during the emplacement of the Mt. Keogan intrusive complex.  Granitic sheets were emplaced syn-tectonically into the developing shear zone as previously suggested by Carr (1995) and Brown et al. (2012).  Widespread, relatively planar felsic layers are injections of thin, concordant granitic sheets from minor incorporation of host rocks (Miller and Paterson, 2001).  Carr (1991) states that these sheets may play an important role in localization of shear zones, which has also been observed in the localized zones of finer grained minerals seen in this study (Figure 29).  The abundance of melts in the system most likely led to a drastic decrease in strength in the middle crust (Glombick et al., 2006).  This decrease in strength assisted in dissipating the gravitational potential energy associated with the thickened crustal welt by thinning and flowing in the weak middle crust (Glombick et al., 2006).  This hypothesis led them to believe that the shear zone is associated to channel flow and not extensional faulting, but may have been responsible for the initiation of the regional extension. 47  As the granitic sheets were emplaced, they were folded by shear along the mylonitic foliation (Figure 30).  These folds were rotated towards and/or formed orientations close to the stretching lineation direction.  The monzodioritic to granitic rocks that make up the majority of the Mt. Keogan intrusive complex are more intensely deformed.  The coarse nature of the igneous protoliths provides good strain markers for finding stretching lineations and observing other kinematic indicators.  S-C fabrics show top-down-to-the-west-northwest, consistent with the WNW dipping extension within the OVsz.  The mafic and felsic schlieren, which are common to sheeted zones (Paterson et al., 2008) help to identify folds and structures seen in the rocks.  Schlieren probably result from flow sorting and fractionation within the sheets, and to a lesser possibility from magma mixing and digestion of host rock inclusions (Miller and Paterson, 2001).     In the Green Lake metasedimentary complex the greater extent of folds and range of fold axis orientations may reflect a less steady state flow regime closer to the OVdf.  Alternatively, some of the folds may predate the intrusions in the Mt. Keogan intrusive complex and the initialization of the OVsz.  The structural section through the OVsz may not be complete as the movement on Diego’s Fault and other small faults may have removed sections (Figure 31). Alsop and Holdsworth (2004) describe a model of shear zone development that has two typical fold associations: (1) an early phase of tight to isoclinal, highly curvilinear folds that contain mylonitic limbs and low-strain hinges.  Sheath folding is associated with the early phase; (2) one or more generations of syn-shearing folds which are completely related to the shear zone.  The occurrence of sheath folds in Outcrop 1 (Figure 28) fits into this model.  Plane strain non-coaxial shear is responsible for the rotation of hinges towards the transport parallel mineral lineations during intense ductile shearing (Alsop and Holdsworth, 2004).  Flow perturbation folding is associated with this later phase.  Progressive deformation creates continuous overprinting of structures that makes interpretation of any pre-existing relationships difficult (Alsop and Holdsworth, 2004).  6.4 TEMPERATURE CONDITIONS DURING DEFORMATION  The deformation of the granitic rocks of the Mt. Keogan intrusive complex has not involved any significant breakdown of the primary igneous minerals (K-feldspar, plagioclase,  48Figure 30: Folded and sheared granite sheet within the granitic to monzogranitic rocks of the MKic (sample MT4A2i). 2cmSm49Figure 29: Schematic cross section along A-A’ (see Plate 1).  05001000Elevation (masl)n.v.e120Distance (m)Mt. KeoganOVdfDiego’s FaultInferred normal faultsDetachment faultInferred lithological contactLithological contactAA’Folded schlierenFeldspar augenFolded S0/S 1Penetrative mylonite fabricGLmcGLmcGreen Lake metasedimentary complexMKrlRattlesnake Lake granite sheetMKicMKqmMKwmMt. Keogan intrusive complexMt. Keogan quartz-monzograniteMt. Keogan white marbleLEGEND50  hornblende and biotite).  This suggests that deformation occurred at relatively high subsolidus temperatures and under relatively dry conditions, otherwise there would be more biotite, muscovite and actinolite (Yardley, 1989).  Although feldspars are mainly deforming ductilely by dynamic recrystallization (Figure 10), there is certain areas where they are fractured anti- or synthetically (Figure 16), which could be attributed to strain heterogeneities in the rocks.  K-feldspar begin to deform ductilely around 450-600°, beginning with dislocation glide and eventually dislocation climb and recrystallization become possible (Passchier and Trouw, (2005).  Fluctuations in heat could have played a large factor into the brittle/ductile response of many of the mineral assemblages.  As new injections of magma are introduced into the system the temperatures would be elevated.  Areas that were closer to the edge of the intrusion would be drastically cooler due to its association with the colder wall rocks.  The continuous exhumation and decrease in overburden stress would also contribute the brittle/ductile response (Carr, 1995).  Owing to an abundance of secondary chlorite and the fact that the majority of the internal deformation is taken up the quartz and not by the feldspars and hornblendes, the final mylonitic fabric probably equilibrated at a lower temperature (greenschist- to amphibolite-facies) than the rocks in the Mt. Keogan intrusive complex (Yardley, 2005).  This suggests that the Mt. Keogan intrusive complex represents deformation deeper in the crust and further away from the detachment fault and the deformation preserved in the Green Lake metasedimentary complex.  This is consistent with the localization of strain closer to the OVdf as the footwall was exhumed to shallower depths (Brown et al. 2012).    6.5 DISPLACEMENT ON DIEGO’S FAULT  There is a set of N-S striking faults that are visible in air photos of the field area (Figure 5).  The faults have a normal shear sense with hanging wall down-to-the-west as inferred by Johnson (2006) and Brown (2012).  No piercing points were found in the field to confirm this. The faults themselves are perpendicular to the movement vector along the OVdf and are possibly related to the late brittle stages of exhumation.  During field mapping it was evident that there is a change in rock type along Diego’s Fault, and assuming that it is a normal fault, it would have juxtaposed the roof rocks of the Green Lake metasedimentary 51  complex and the upper part of the OVsz against the metamorphosed rocks of the Mt. Keogan intrusive complex, a lower section of the OVsz (Figure 31).  6.6 RESULTS COMPARED TO PREVIOUS RESEARCH  Ross and Christie (1979) completed their research before the idea of a shear zone was widely accepted for the Shuswap metamorphic complex.  They proposed upwards of five deformation events spanning the Paleozoic to the Pleistocene ages, although no dating had been done to the rocks.  Even though they conclude that there is one major penetrative mylonitic fabric that overprints the entire region, and that granitic sheets have been syn-tectonically emplaced into the succession of pre-existing rocks, this study has found no conclusive evidence for more that one major deformation event within the Mt. Keogan intrusive complex, and no more than two in the Green Lake metasedimentary complex.   The cross sections completed by Ross and Christie (1979) (Figure 3) try to correlate many packages of rocks over great distances.  As seen in this study, the nature of the Mt. Keogan intrusive complex and its varying emplacement times, make correlation of any rock types difficult over even small distances.  The anastomosing behaviour of mylonite zones allows for a variety of fold axes orientations, especially as deformation continues and rotates them towards the direction of shear.   The recent study by Brown et al. (2012) describes a more plausible portrayal of an extensional shear zone, originally defined by Tempelman-Kluit and Parkinson (1986).  Their age dating has helped to identify the relative timing of emplacement of some of the intrusions found in the Mt. Keogan intrusive complex.  They claim that the Okanagan gneiss is closely associated with the OVsz, and probably would not exist without it. Their study, along with this one, concludes that there is a possible earlier fabric preserved in the Green Lake metasedimentary complex (Figure 27),  but the extensive deformation along the OVsz has destroyed most of the evidence.    It is now widely accepted that the structures preserved in the Shuswap metamorphic complex are all resultant from progressive extensional general shear strain within the OVsz.  Many of the elements seen in this study’s field area have been observed in other parts of the OVsz along the 400+ km length of the OVdf (Coney and Harms, 1984; Okulitch, 1984; Carr, 1992; Bardoux and Mareschal, 1994; Carr, 1995; Johnson and Brown, 1996; Glombick et al., 2006; Johnson, 2006; Twomey, 2014) 52  6.7 TECTONIC SETTING AND DEVELOPMENT OF THE OVSZ   Following collision of the Intermontane belt with the western edge of North America, crustal thickening had taken place and created a large crustal welt (Bardoux and Mareschal, 1994).  Owing to the Lack of early Tertiary sedimentary sequences within the Omineca Crystalline Belt, Bardoux and Mareschal (1994) believe that the entire region was elevated high enough to experience gravitational collapse and was exposed to large periods of erosion.  It is this gravitational collapse that led to the creation of the OVsz and the subsequent exhumation of the Shuswap metamorphic complex. At the beginning of the extensional process in the late Cretaceous, the rocks of the Shuswap metamorphic complex were at 700°C and 600MPa, indicating that they were deeply buried within the crust (Bardoux and Mareschal 1994).  There is no evidence observed in the field area that the temperature and pressure gradients ever got that high, as the K-feldspar grains where just beginning to recrystallize and there is no evidence for partial melting.  Associated with many orogenic belts is large elongate plutons emplaced by the injection of multiple dyke-like sheets of magma (Miller and Paterson, 2001).  Coney and Harms (1984) suggest that extension was initiated by a combination of sharp pulses of magmatism brought on by the thickened crustal welt and a reduction in regional inter-plate stress (also Eyal et al., 2006). The presence of melts created by dehydration melting of amphibolite (Engebretson and Gordon, 1984) may have facilitated movement on pre-existing shear zones related to the early collisional events which may also explain the relatively shallow nature of the OVdf (Bardoux and Mareschal, 1994).     The range in orientations of fold axes and axial planes is related to the anastomosing character of mylonite zones.   A variation of up to 40° in stretching lineations is a common feature as the stretching lineation must vary around ellipsoid pods contained within the rock (Bell and Hammond, 2011).  The fold axes that lie sub-parallel to the stretching lineation is also very common, as most folds are rotated into the shear direction given enough shearing has taken place. Owing to this, these folds are not good sense-of-shear indicators because their original asymmetry has changed and could show a false sense-of-shear (Bell and Hammond, 2011).  The more reliable S-C and C’ fabrics and mica fish (Lister and Snoke, 1984) give a definitive top-down-to-the-WNW sense of movement along the OVdf (Figure 32).   53Figure 31:  Mica fish and shear banding indicating sense of shear (sample MT1D).PPL1080.4 mm54  Extension closer to the surface, in the brittle regime, allowed fluids to be incorporated into the OVsz, and reacting with the minerals at elevated temperatures created secondary retrograde alteration minerals such as chlorite and sericite.    7. CONCLUSION The Okanagan Valley shear zone formed in response to extensional collapse of a thickened crustal welt during the Eocene (Brown et al., 2012).  The OVsz is an approximately 1.5 km-thick ductile shear zone that is capped by a brittle detachment plane (OVdf) (Twomey, 2014).  The predominant linear element is elongation lineations that trend approximately towards 290° and leave a trace of extension direction.  The Okanagan Valley detachment fault delineates the western-most margin of the OVsz.  Late brittle extension across the OVdf has caused westward dipping normal faults to juxtapose the country rocks of the Green Lake metasedimentary complex beside the rocks of the Mt. Keogan intrusive complex.  The footwall rocks of the Shuswap metamorphic complex were exhumed along the OVsz, progressively overprinting the pre-existing fabrics with mylonitic and cataclastic fabrics.  The peak metamorphic grade reached by the rocks of the OVsz is upper greenschist- to amphibolite-facies, with a peak temperature of approximately 500-600° and may have occurred prior to extension.  The entire region of the OVsz is buckled and crenulated, which occurred syn-deformation (Glombick et al., 2006; Brown et al. 2012).  This is seen in outcrop scale as well as in stereonet analysis in the sub-horizontal variation of planar fabrics (Figure 12b-i-ii).   There are two lithological domains within the field area to the west of Vaseaux Lake: a metasedimentary complex (GLmc) recognized as being the country rock; and an intrusive complex (MKic) that intruded into the country rock before or during extension.  Extension and shear-sense are constrained through kinematic indicators to be top-down-to-the-west-north-west, confirming previous studies in the direct area by Tempelman-Kluit and Parkinson (1986) and Brown et al. (2012).     55  REFERENCES Alsop, G.I. and Holdsworth, R.E., 2004.  Shear zone folds: records of flow perturbation or  structural inheritance?  Geological Society of London, v. 224, p. 177-199.  Armstrong, R.L., Parrish, R.R., van der Heyden, P., Scott, K., Runkle, D. and Brown, R.L.,  1991.  Early Proterozoic basement exposures in the southern Canadian Cordillera:  core gneiss of Frenchman Cap, Unit I of the Grand Forks Gneiss, and the Vaseaux  Formation.  Canadian Journal of Earth Sciences, v. 28, p. 1169-1201.  Bardoux, M. and Mareschal, J-C., 1994.  Extension in south-central British Columbia:  mechanical and thermal controls.  Tectonophysics, v. 238, p. 451-470.  Bell, T.H., and Hammond, R.L., 2011.  On the internal geometry of mylonite zones.  The  Journal of Geology, v. 92, p. 667-686.  Brown, S.R., Gibson, H.D., Andrews, G.D.M., Thorkelson, D.J., Marshall, D.D., Vervoort,  J.D. and Rayner, N., 2012.  New constraints on Eocene extension within the Canadian  Cordillera and identification of Phanerozoic protoliths for footwall gneisses of the  Okanagan Valley shear zone.  Lithosphere, v. 4, p. 354-377.  Carr, S.D., 1991.  Three crustal zones in the Thor-Odin – Pinnacles area, southern Omineca  Belt, British Columbia.  Canadian Journal of Earth Sciences, v. 28, p. 2003-2023.    Carr, S.D., 1995.  The southern Omineca Belt, British Columbia: new perspectives from the  Lithoprobe Geoscience Program.  Canadian Journal of Earth Sciences, v. 32, p. 1720- 1739.  Coney, P.J., and Harms, T.A., 1984.  Cordilleran metamorphic core complexes: Cenozoic  extensional relics of Mesozoic compression.  Geology, v. 12, p. 550-554.  Engebretson, D.C., Cox, A. and Gordon, R.G., 1984.  Relation motions between oceanic  plates of the Pacific Basin.  Journal of Geophysical Research, v. 89, p. 10,291-10,310.  Ewing, T.E., 1980.  Tectonic evolution of the Pacific Northwest.  The Journal of Geology,  v. 88, p. 619-638.  Eyal, Y., Osadetz, K.G., and Feinstein, S., 2006.  Evidence for reactivation of Eocene joints  and pre-Eocene foliation planes in the Okanagan core-complex, British Columbia,  Canada.  Journal of Structural Geology, v. 28, p. 2109-2120.  Gibson, H.D., Brown, R.L., Carr, S.D., 2005.  U-Th-Pb geochronologic constraints on the  structural evolution of the Selkirk fan, northern Selkirk Mountains, southern  Canadian Cordillera.  Journal of Structural Geology, v.27, p. 1899-1924.  56  Glombick, P., Thompson, R.I., Erdmer, P. and Daughtry, K.L., 2006.  A reappraisal of the  tectonic significance of early Tertiary low-angle shear zones exposed in the Vernon  map area (82 L), Shuswap metamorphic complex, southeastern Canadian Cordillera.   Canadian Journal of Earth Sciences, v. 43, p. 245-268.  Johnson, B.J., 2006.  Extensional shear zones, granitic melts, and linkage of overstepping  normal faults bounding the Shuswap metamorphic core complex, British Columbia.   Geological Society of America Bulletin, v. 118, p. 366-382.  Johnson, B.J. and Brown, R.L., 1996.  Crustal structure and early Tertiary extensional  tectonics of the Omineca belt at 51°N latitude, southern Canadian Cordillera.   Canadian Journal of Earth Sciences, v. 33, p. 1596-1611.  Johnson, D.H., Williams, P.F., Brown, R.L., Crowley, J.L. and Carr, S.D., 1999.   Northeastward extrusion and extensional exhumation of crystalline rocks of the  Monashee complex, southeastern Canadian Cordillera.  Journal of Structural  Geology, v. 22, p. 603-625.  Lane, L.S., Ghent, E.D., Stout, M.D. and Brown, R.L., 1988.  P-T history and kinematics of  the Monashee Décollement near Revelstoke, British Columbia.  Canadian Journal of  Earth Sciences, v. 26, p. 231-243.  Lister, G.S. and Price, G.P., 1977.  Fabric development in a quartz-feldspar mylonite.   Tectonophysics, v. 49, p. 37-78.  Lister, G.S. and Snoke, A.W., 1984.  S-C Mylonites.  Journal of Structural Geology, v. 6, p.  617-638.  Miller, R.B. and Paterson, S.R., 2001.  Construction of mid-crustal sheeted plutons:  Examples from the North Cascades, Washington.  Geological Society of American  Bulletin, v. 113, p. 1423-1442.  Monger, J.W.H., Price, R.A. and Tempelman-Kluit, D.J., 1982.  Tectonic accretion and the  origin of the two major metamorphic and plutonic welts in the Canadian Cordillera.   Geology, v. 10, p. 70-75.  Nelson, J. and Colpron, M., 2007.  Tectonics and Metallogeny of the British Columbia,  Yukon and Alaskan Cordillera, 1.8 Ga to the Present.  Mineral Deposits of Canada: A  Synthesis of Major Deposit-Types, District Metallogeny, the Evolution of Geological  Provinces, and Exploration Methods: Geological Association of Canada, Mineral  Deposits Division, Special Publication No. 5, p. 755-791.   Okulitch, A.V., 1984.  The role of the Shuswap metamorphic complex in Cordilleran  tectonism: a review.  Canadian Journal of Earth Sciences, v. 21, p. 1171-1193.   57  Parrish, R.R., Carr, S.D. and Parkinson, D.L., 1988.  Eocene extensional tectonics and  geochronology of the southern Omineca Belt, British Columbia and Washington.   Tectonics, v. 7, p. 181-212.  Passchier, C.W. and Simpson, C., 1986.  Porphyroclast systems as kinematic indicators.   Journal of Structural Geology, v. 8, p. 831-843.  Passchier, C.W. and Trouw, R.A.J., 2005.  Micro-tectonics.  Springer-Verlag, Berlin, 366 p.  Paterson, S.R., Žák, J. and Janoušek, V., 2008.  Growth of complex sheeted zones during  recycling of older magmatic units into younger: Sawmill Canyon area, Tuolumne  batholith, Sierra Nevada, California.  Journal of Volcanology and Geothermal Research, v. 177, p. 457-484.  Ross, J.V. and Christie, J.S., 1978.  Early recumbent folding in some westernmost exposures  of the Shuswap Complex, southern Okanagan, British Columbia.  Canadian Journal  of Earth Sciences, v. 16, p. 877-894.  Simpson, C., and Schmid, S.M., 1983.  An evaluation of criteria to deduce the sense of  movement in sheared rocks.  Geological Society of America Bulletin, v. 94, p. 1281- 1288.  Singleton, J.S., 2012.  Development of extension-parallel corrugations in the Buckskin- Rawhide metamorphic core complex, west-central Arizona.  Geological Society of  America Bulletin, v. 125, p. 453-483.   Tempelman-Kluit, D. and Parkinson, D., 1986.  Extension across the Eocene Okanagan  crustal shear in southern British Columbia.  Geology, v. 14, p. 318-321.  Twomey, V., 2014.  Three dimensional strain distribution and deformation temperature  interpreted from quartz microstructures and petrofabrics in the Okanagan Valley  shear zone, southern Canadian Cordillera.  M.Sc. thesis, Simon Fraser University, Vancouver, 128 p.  van der Pluijm, B.A. and Marshak, S., 2004.  Earth Structure.  W.W. Norton and Company,  New York, 656 p.  Yardley, B.W.D., 1989.  An introduction to metamorphic petrology.  Longman Earth Science  Series, New York, 247 p.    58Stn	  # North East Elev.	  (m) Trend Plunge Type Strike Dip Type Sample Ornt. Field	  Desc. Sketch Photo1 MT01Agreenish-­‐blue,	  crystalline,	  disseminated	  sulphide	  bearing,	  oxidizes	  reddish-­‐brownMT01B-­‐Dlocated	  ~5m	  above	  A,	  much	  greener,	  definite	  banding,	  larger	  sulphides,	  finer	  crystalline,	  heavily	  fractured2 MT02Aorange	  oxidation,	  soft	  and	  unconsolidated,	  visible	  folding,	  Qtz,	  plage,	  k-­‐spar,	  very	  fine	  grained,	  signs	  of	  recystallization Y YMT02Blight	  green,	  crystalline,	  vuggy	  w/	  qtz	  in	  small	  fractures,	  disseminated	  sulphides	  (less	  than	  STN	  1),	  no	  obvious	  orientationMT02Cfloat	  in	  treewell,	  light	  green	  banded	  (epidote?),	  dark	  green	  folded	  (chlorite?)	  banding	  foliation	  seems	  to	  run	  through	  both	  (odd	  contact),	  small	  qtz	  veining,	  brown	  oxidation YMT02Dfloat	  in	  tree,	  light	  green	  and	  dark	  green	  banding,	  visible	  folds	  (no	  orientation),	  one	  side	  shows	  striations,	  qtz,	  chlorite?3 180 42 Fold	  Axis 193 64 Right	  Limbwest	  facing	  outcrop,	  steeply	  plunging	  fold	  (synform),	  right	  limb	  measured Y4 MT04Afloat,	  same	  green	  rock,	  large	  S-­‐fold	  (leucosome),	  matrix	  is	  crystalline,	  chlorite? Y YMT04B float,	  great	  example	  of	  fold5 115 82 Foliation	  (CB)MT05A on	  rockarea	  shaped	  somewhat	  like	  a	  drumlin,	  think	  it's	  relict	  shape	  of	  an	  antiform Y YMT05B float,	  hollowed	  out	  syn/anti	  form,	  stretching	  lineations6 MT06A-­‐Hlarge	  outcrop,	  has	  multiple	  rock	  types,	  breccia	  piles?,	  maybe	  all	  related7 MT07AMT07B8 cobble	  conglomerate	  from	  brittle	  hanging	  wall	  of	  detachment9 MT09Amajor	  red-­‐brown	  staining,	  very	  fine-­‐grained	  crystalline,	  green,	  minor	  qtz	  veiningMT09B fine	  grained	  crystalline,	  minor	  sulphides,	  minor	  qtz	  veiningMT10A coarse	  grained	  crystalline,	  darker	  green,	  stockwork	  veining10 MT10B finer	  grained	  than	  A,	  lots	  of	  stockwork	  veining11 MT11Alarge	  s-­‐folds,	  higher	  grade	  metamorphism	  more	  folding	  and	  migmatization12JACKPOT!	  Large	  overturned/inclined,	  tight	  fold,	  many	  small	  scale	  folds	  inside Y13 285 12 fold	  axis	  (tight	  chevron	  fold)114 46 limbfirst	  sign	  of	  E-­‐W	  trending	  compression,	  open	  crenulation	  folding,	  subvertical	  qtz	  veining,	  down	  west	  side	  of	  cliff	  rocks	  get	  more	  pegmatitic,	  granitic	  gneissic,	  big	  k-­‐spar	  eyes Y Y14 314 18 fold	  axis 30 18 limb crenulations	  of	  different	  orientation245 20 limbUTM Structural	  Measurement Photo	  UTM5915NE	  Cliff,	  intrusive	  qtz	  veining	  with	  crazy	  shape,	  did	  intrusion	  bend	  rocks	  upward? Y16 5462175 0312230 493 MT16A 229/67green(chlorite)	  quartz	  crystalline	  rock,	  signs	  of	  banding	  towards	  South,	  mineral	  segregation,	  small	  stockwork	  veining	  (undeformed),	  **	  further	  south	  fold	  hinge	  found,	  same	  chlorite-­‐rich,	  minerals	  showing	  more	  definite	  separation	  nowMT16B float,	  good	  representation	  of	  close	  chevron	  foldMT16C float,	  vuggy	  quartz	  with	  sulphidesMT16Dheavily	  banded	  qtz,	  bluish	  tarnish	  or	  staining	  (thought	  it	  was	  moly)16E 5462145 0312227 498 MT16Eoverlayn	  by	  MT16D,	  dark	  green,	  chl-­‐rich	  crystalline	  rock,	  disseminated	  sulphides17 5462113 0312213 498 MT17A weakly	  banded	  chl-­‐qtz-­‐plage-­‐biotite,	  larger	  band	  of	  qtz	  on	  top18 5462088 0312216 503 MT18A banded	  qtz	  with	  chl19 5462080 0312211 498 70 4 fold	  axis 152 6 axial	  surface banded	  qtz Y20 5462083 0312196 498 7 20 Fold	  Axis 347 31 axial	  surfacepossible	  fold	  closure	  protruding	  from	  rock,	  dark	  green,	  coarse	  grained,	  chl-­‐rich Y47 21 Fold	  Axis 358 25 axial	  plane Y21 5462080 0312184 498 84 19 Fold	  Axis 320 19 axial	  surface275 82 Foliation	  (CB)22 5462082 0312181 497 100 16 Fold	  Axis 10 17 top	  limb320 29 axial	  surface23 5462080 0312173 497 120 10 Fold	  Axis 305 42 Foliation	  (CB) Y118 16 Fold	  Axis 320 52 right	  limb	  (synform) Y135 18 Fold	  Axis Y100 6 Fold	  Axis YMT23A	  I	  &	  ii148/89 M	  fold Y278 68 Foliation	  (CB) Y24 5462054 0312194 495looks	  like	  large	  scale	  fold	  falling	  apart	  (antiform),	  striking	  266,	  dipping	  NE Y25 5462046 0312185 497 different	  types	  of	  rocks,	  lots	  of	  change26 5462013 0312166 499 290 34 Foliation	  (CB)27 5461918 0312121 510 relict	  antiform,	  striking	  105/285,	  dipping	  NE Y28 5461939 0312228 510 MT28A qtz,	  biotite	  schist,	  with	  coarse	  grained	  biotite	  chlorite	  qtz	  schist29 5462009 0312261 505 45 25 Fold	  axis 232 59 Top	  limb large	  recumbant	  fold Y154 62 Bottom	  limb270 35 Axial	  surface30 5462066 0312265 493back	  into	  dark	  green	  crystalline	  rock,	  followed	  by	  Chl,	  Bio,	  Qtz	  schist31 5462099 0312275 493 qtzite	  w/	  biotite	  layers32 5462112 0312253 500 foliated	  Chl,	  Qtz	  schist,	  w/	  minor	  disseminated	  sulphides33 5462377 0312083 472 MT33Aacross	  road,	  bluffs	  on	  west,	  maybe	  tuff?	  Andesite?	  Overlayn	  by	  conglomerate?	  	  Too	  dangerous	  to	  climb60MT33BMT33C34 5462494 0312219 470 MT34A chl-­‐rich,	  quartzite	  w/35 5462601 0312282 472 little	  overhang,	  qtz	  breccia?	  Maybe	  float?36 5462530 0312295 474 no	  data37 5461852 0312424 559 270 40 Foliation	  (CB) qtz-­‐biotite	  schist,	  qtz	  vein	  striking	  24338 5461951 0312405 530 301 46 Foliation	  (CB) biotite	  chl	  qtz	  schist302 45 Foliation	  (CB) mostly	  chl	  and	  biotite,	  small	  qtz	  layers39 5461865 0312413 546 almost	  mostly	  quartzite,	  little	  biotite	  banding40 5461864 0312406 545 15 51 fold	  axis 282 47 axial	  surface MT40A 172/54orientation	  face	  is	  underside	  of	  rock,	  great	  sample	  of	  parasitic	  fold,	  shearing	  sense270 48 Bottom	  limb41 5461839 0312382 573 50 50 lineation	  (elongation)238 63 Foliation	  (CB) mineral	  elongation	  in	  mineral	  composition	  layer42 5461816 0312398 569 248 59 Foliation	  (CB) qtz	  biotite	  schist	  (90%	  qtz)43 5461820 0312357 567 qtz-­‐rich	  to	  biotite-­‐qtz	  (90%	  biotite)	  higher	  above44 5461828 0312269 532 back	  into	  chl	  rich,	  biotite	  qtz	  schist45 5461815 0312252 528 325 26 Foliation	  (CB) qtz	  biotite	  schist	  (65%	  qtz)46 5461807 0312282 536 328 19 fold	  axis 240 19 Foliation	  (CB) tight,	  almost	  chevroned	  fold Y47 5461810 0312300 547 0 18 fold	  axis 255 31 axial	  plane Y343 29 fold	  axis 244 32 top	  limb351 31 fold	  axis48 5461751 0312327 544 chl-­‐bio	  schist,	  very	  little	  visible	  qtz49 5461755 0312349 550 chl-­‐qtz	  schist,	  very	  little	  biotite,	  coarser	  grained50 5461775 0312373 546 135 48 Foliation	  (CB) Hail!,	  foliation	  in	  different	  direction51 5461690 0312375 552top	  of	  ridge,	  mostly	  chl-­‐bio-­‐qtz	  schist	  (33%	  each),	  one	  side	  (s)	  more	  chl	  rich	  w/	  more	  qtz	  rich	  underneath52 5461576 0312351 545much	  less	  chl,	  much	  more	  qtz	  (almost	  qtzite	  w/	  small	  biotite	  layers53 5461568 0312309 533 288 38 Foliation	  (CB) qtz	  biotite	  schist54 5461604 0312294 533 355 77 jointing joint	  network55 5461557 0312350 	   MT55A 042/56 almost	  gneissic Y56 5461560 0312356 537 260 0 fold	  axis 280 15 axial	  plane qtz-­‐biotite	  schist	  folded Y280 4 fold	  axis 270 16 axial	  plane57 5461544 0312356 531 278 12 Fold	  Axis 248 15 axial	  plane Y58 5461655 0312383 523 no	  data59 5461970 0312371 487 314 24 Foliation	  (CB) qtz-­‐bio-­‐chl	  schist60 5461907 0312911 648 pegmatite	  intrustion61 5462405 0312959 550 no	  data62 5458683 0314363 479 no	  data63 5459564 0314353 533 MT63 very	  coarse	  grained,	  qtz-­‐rich	  &	  feldspar64 5459913 0314268 615 MT64weak,	  almost	  horizontal	  compositional	  banding,	  very	  coarse	  grained,	  qtz-­‐kspar,	  some	  dark	  mineral	  that	  darkens	  the	  qtz6165 5459912 0314256 612 MT65musc?,	  chl,	  garnet,	  plage,	  qtz,	  very	  schistose,	  almost	  gneissic,	  **right	  beside	  MT64,	  possible	  folds	  in	  minerals Y66 5459928 0314240 612 MT66 very,	  very	  coarse,	  macrocrysts,	  slightly	  foliated67 5459937 0314250 621 MT67very,	  very	  coarse,	  more	  chl,	  much	  more	  garnet,	  walking	  up	  into	  garnet	  zone?68 5459967 0314255 628 MT68 more	  garnet,	  darker	  (more	  Hbld?)69 5459976 0314252 627 MT69garnets	  2-­‐4mm	  in	  fine	  grained	  mass	  surrounded	  by	  coarse	  grained,	  minor	  shear	  zone?	  Possible	  foliation	  and	  lineation	  measurements70 5459986 0314247 633 MT70large	  stretching	  structure,	  maybe	  large	  recumbant	  fold?	  More	  granitic	  looking,	  still	  has	  garnets Y71 5460060 0314291 643 MT71 large	  crystals,	  light	  and	  dark	  bands,	  garnets72 5460148 0314329 648 no	  data73 5460166 0314325 660lineations,	  compositional	  banding,	  many	  more	  bigger	  garnets,	  clusters	  and	  large	  bands74 5460174 0314338 660 possible	  fold	  hinge,	  recumbant Y75 5460212 0314350 683 MT75 a	  lot	  more	  biotite	  rich!	  Foliated76 5460265 0314383 699 much	  more	  musc-­‐qtz	  schist77 5460318 0314386 722fold	  and	  shear	  sense	  indicators,	  can	  see	  down	  fold	  axis	  and	  it	  is	  curved Y78 5460329 0314380 731 large	  antiform	  with	  small	  folds	  inside79 5460367 0314396 729 large	  boulder,	  with	  sample	  of	  upper	  cliff80 5460402 0314467 726 MT8081 5460604 0314576 764 no	  data82 5460747 0314524 784 no	  data83 5460804 0314532 799 no	  data84 5460844 0314532 801 fold	  in	  rocks	  w/	  axis	  and	  planes85 5461279 0314481 864 large	  recumbant	  fold Y86 5461348 0314371 865 no	  data87 5461067 0314115 863 no	  data88 5460744 0314048 889 TOP!89 5460804 0314064 881 no	  data90 5460842 0314050 869 no	  data91 5460875 0314018 872 no	  data92 5460899 0313975 861 no	  data93 5460899 0313861 842 no	  data94 5460865 0313752 829large	  round	  worn	  outcrop,	  lots	  of	  lichen	  and	  moss,	  but	  can	  probably	  get	  some	  measurements95 5461038 0313351 723 no	  data96 5461134 0313130 659 no	  data97 5461364 0313019 606 no	  data98 5455542 0311552 469 Y	  into	  valley	  or	  up	  to	  bluffs99 5461819 0313130 590 Y	  at	  mid-­‐valley62100 5461907 0313177 574 T	  at	  north	  end	  of	  valley101 5462038 0313239 608 foliation	  measurements,	  and	  possible	  fold	  measurements Y102 5462050 0313237 616 large	  scale	  fold,	  dyke	  is	  folded103 5462111 0313248 634lots	  of	  measuements,	  oriented	  samples,	  huge	  fold	  hinge	  with	  many	  tiny	  folds	  arounds	  it,	  vertical	  fabric	  in	  hinge	  of	  fold,	  find	  minor	  sub	  horizontal	  folds	  in	  hinge	  too Y104 5462171 0313396 656 superman	  fold Y105 5462202 0313578 677 Y	  behind	  bluff,	  towards	  ENE106 5462343 0313902 747 no	  data107 5462202 0313893 768 MT107 dyke	  imntruding,	  maybe	  not	  folded?108 5462155 0313925 763 foliation	  measurements	  on	  path109 5462114 0313987 780 MT109 kspar	  crystals	  in	  green	  groundmass?110 5462098 0314008 782 MT110shear	  zone?	  Stretching	  lineations,	  pressure	  shaddows,	  large	  coarse	  grained	  crystals,	  kspar	  &	  biotite111 5462053 0314112 767 Y	  NE	  corner,	  into	  pond,	  SW	  arm	  may	  lead	  back	  to	  last	  unknown	  Y	  below112 5461779 0314518 800 no	  data113 5461605 0314539 814 no	  data114 5461343 0314497 854 very	  muscovite	  rich	  section,	  outcrops	  falling	  apart	  along	  foliation115 5461021 0314086 867 come	  back	  and	  look	  at	  outcrops!116 5460811 0314183 899 shear	  bands,	  looks	  like	  they	  dip	  SE?117 5460464 0314285 883 no	  data118 5460473 0314264 885 no	  data119 5460519 0314233 880 no	  data120 5460635 0314283 898 no	  data121 5460747 0314284 897 no	  data122 5461012 0313819 826 no	  data123 5461025 0313743 819 no	  data124 5461162 0313506 742 274/6 folded	  outcrop,	  may	  have	  oriented	  piece,	  flat	  top	  strike/dip Y125 5462449 0313521 655 no	  data126 5461321 0314633 872 fold	  at	  top	  of	  south	  top,	  lots	  of	  measurementds,	  oriented	  samples127 5461190 0314554 847 MT127 coarser	  grained,	  musc-­‐rich,	  foliations	  to	  measure128 5461189 0314554 850 no	  data129 5460902 0314539 818 no	  data130 5460902 0314539 819 very	  biotite	  rich,	  right	  mineralogy	  for	  indicator	  minerals?131 5460377 0314474 718 mylonites132 5460220 0314400 693 boudin?	  Folds133 5460172 0314356 680 no	  data134 5459529 0314363 524Rattlesnake	  Lake,	  leucocratic,	  foliated,	  stretching	  lineations	  (possibly),	  feldspar,qtz,plage,musc,biotite,	  L-­‐tectonites,	  partial	  melts	  in	  shear,	  solidifying	  during	  stretch,	  pegmatite	  horizons,	  protolith	  -­‐-­‐>	  peraluminous	  granitoid?	  ~50Ma	  (Eocene),	  garnets,	  orthogneiss?135 5458712 0314282 485 no	  data63136 5462090 0312174 494 no	  data137 5462090 0312174 494 no	  data138 5459945 0314493 650no	  muscovite,	  more	  mylonitic,	  large	  garnets,	  many	  small,	  float	  samples	  shows	  movement	  on	  crystals139 5460184 0314444 693k-­‐spar	  porphyroclasts,	  biotite-­‐rich,	  garnets,	  +qtz,	  full	  of	  k-­‐spar,	  orthogneiss?	  -­‐-­‐>	  highly	  sheared	  and	  mylonitized,	  dynamic	  recrystalization,	  extensive	  deformation,	  shear	  from	  fault	  plane,	  large	  intrusive	  veins	  (less	  deformed,	  maybe	  intruded	  along	  foliation,	  leucocratic),	  **keep	  track	  of	  ratio	  of	  leuco	  to	  mafic,	  if	  there	  is	  sillimanite,	  might	  be	  pelitic,	  makes	  k-­‐spar,	  otherwise	  biotite-­‐qtz-­‐diorite??	  garnets	  igneous??,	  thin	  intrusive	  units,	  k-­‐spar	  w/	  biotite,	  weak	  crenulation	  in	  biotite,	  highly	  strained,	  different	  intercollations	  of	  igneous	  intrusions,	  there	  is	  paleozoic	  sedimentary	  packages	  in	  area,	  all	  horribly	  deformed140 5460437 0314573 746 MT140heavily	  mylonitized,	  massive	  grainsize	  reduction,	  shear	  sense	  indicators141 5460805 0314261 917chl	  (secondary,	  much	  more),	  (Fe,Mg)-­‐rich	  calc-­‐silicates,	  amphibolite,	  hornblende	  (both	  igneous	  &	  metamorphic,	  different	  compositions),	  responsible	  for	  change	  in	  grain	  size?,	  mafic,	  epidote	  (retrograde),	  coarse	  and	  fine	  grained,	  gneissic	  &	  schistose,	  changes	  in	  strength	  of	  foliation	  (changes	  in	  strain	  partitioning),	  qtz-­‐kspar	  veining	  (pre-­‐syn	  deformation),	  resistant	  to	  weathering	  (competant	  rocks,	  responsible	  for	  the	  bluffs)142 5462098 0313259 655143 5462300 0313709 746144 5462351 0313909 753145 5462295 0313862 761146 5462167 0313901 771147 5462153 0313926 770148 5462103 0314020 805149 5462122 0314022 800150 5462142 0314014 795151 5462287 0313736 725152 5462350 0313910 765 MT152 050/75153 5461340 0314632 875154 5458738 0314983 854155 5459048 0314920 532156 5460176 0314429 707157 5459961 0314254 641158 5459220 0313786 511159 5459251 0313800 50464outcrop	  contains	  lineations,	  fabrics	  and	  folds.	  Overall	  composition	  of	  rocks	  are	  mafic.	  	  Location	  is	  approx.	  50m	  from	  Green	  Lake	  Rd	  where	  detachment	  fault	  is	  located.	  	  No	  obvious	  sign	  of	  shear	  surface,	  but	  definite	  signs	  of	  polyphase	  deformation.1A 5462080 0312207 501 92 2 intersection 281 62 Foliation	  (CB)rock	  is	  very	  qtz	  rich	  (90%),	  minor	  chl	  (after	  biotite),	  schistose,	  fine	  grained,	  minor	  injection	  veins,	  leucocratic	  (feldspar?),	  oxidized	  phases94 11 Fold	  Axis 281 55 Foliation	  (CB)291 37 Foliation	  (CB)1B 298 43 Foliation	  (CB)fine	  grained	  leucocratic	  bands,	  may	  have	  feldspar,	  on	  metre	  scale	  it	  varies	  from	  :	  >95%	  qtz	  (fine	  grained,	  retrograde	  chl);	  Biotite-­‐qtz	  schist	  w/	  feldspar	  crystals,	  small	  qtz	  veins,	  sharp	  contacts,	  coarser	  grained.	  	  ***melt	  will	  include	  more	  feldspar,	  possible	  layer	  of	  fine	  biotite	  around	  intrusion,	  two	  ways	  to	  get	  feldspar	  :	  melt	  or	  breakdown	  of	  muscovite	  &	  sillimanite1C 115 10 Fold	  Axis 285 64 Foliation	  (CB)MT1C 149/89outcrop	  is	  almost	  parallel	  to	  compositional	  banding,	  still	  very	  qtz-­‐rich,	  not	  as	  much	  chl,	  maybe	  more	  biotite Y319 17 Axial	  Plane297 33 Foliation	  (CB)292 48 Foliation	  (CB)325 25 Axial	  Plane306 31 Foliation	  (CB)areas	  with	  good	  contacts	  along	  coarser	  qtz	  crystals	  (possible	  veins),	  others	  just	  qtz	  rich	  layers,	  more	  chl	  in	  the	  rocks	  (after	  biotite),	  qtz-­‐biotite	  schist1D 299 41 Foliation	  (CB) Y291 36 Foliation	  (CB)MT1D 180/86 Y291 57 Foliation	  (CB)278 42 Foliation	  (CB) qtz-­‐biotite	  schist,	  20%	  biotite,	  some	  chl	  alteration1E 339 12 Axial	  Plane MTZ1E 043/80	  underside Y Y121 7 Fold	  Axis 324 28 Axial	  Plane1F 0 34 Foliation	  (CB)Rock	  much	  more	  chl-­‐rich,	  folding	  visible	  within	  intrusive	  dykes	  (small	  scale-­‐mm),	  folds	  verging	  steeply	  to	  the	  SW,	  sub-­‐horizontal	  axial	  plane90 6 Fold	  Axis 55 21 Axial	  Plane MTZ1F 001/87181	  -­‐	  strike	  of	  face,	  dip	  87	  (underface),	  axial	  trace	  is	  21	  from	  horizontal	  to	  SE Y Y1A1 5462081 0312208 5031A4 5462085 0312182 4921A5 5462090 0312175 4941A6 5462092 0312170 4921A7 5462096 0312177 4941A8 5462100 0312182 502OUTCROP	  #165section	  of	  outcrop	  has	  limited	  visibility	  due	  to	  lichen	  and	  moss.	  	  Polyphase	  peformation	  apparent.	  	  Local	  faulting	  -­‐	  subhorizontal?	  Collapse	  somewhere?	  Curved	  foliations,	  layout	  measurements	  :	  A-­‐B,	  7.6m	  towards	  345;	  B-­‐C,	  14.2m	  towards	  021,	  4.8m	  towards	  055 Y Y2A1 5462049 0313247 622 320 45 Foliation	  (CB)MT2A1 felsic	  intrusive	  rock,	  amphibolite?30 35 Foliation	  (CB)MT2A2green	  chl-­‐rich,	  fine	  grained	  schist,	  folded	  vein	  is	  surrounded	  by	  finer	  grained	  chl-­‐biotite-­‐rich,	  SE	  vergence,	  undulatory	  signs	  in	  intrusive	  felsic	  (subhorizontal,	  maybe	  slightly	  twisted?),	  banded	  veins	  show	  crenulation Y15 40 Foliation	  (CB)66 29 Foliation	  (CB)115 19 Foliation	  (CB)335 25 Foliation	  (CB)OUTCROP	  #2Blayour	  measurements	  :	  E-­‐F,	  7.8m	  towards	  328;	  F-­‐G,	  10.7m	  towards	  347;	  G-­‐H,	  6.2m	  towards	  336;	  H-­‐I,	  4.9m	  towards	  0352B1 5462078 0313250 630 75 58 Fold	  Axis 10 25 Foliation	  (CB)MT2B1 185/68 Seeing	  shallower	  foliations11 46 Foliation	  (CB)354 46 Foliation	  (CB)38 39 Foliation	  (CB)25 35 Axial	  PlaneRock	  is	  folded	  in	  a	  large	  recumbant	  fold,	  verging	  NW.	  Minor	  fold	  within	  the	  larger	  fold	  show	  same	  geometry,	  some	  leucocratic	  differentiation,	  still	  very	  green Y YLarge	  Fold48 24 Fold	  Axis 31 31 Axial	  Plane310 13 Top	  Limb26 58 Bottom	  LimbSmall	  Folds 16 57 Bottom	  LimbMT2B2 016/57	  (underside,	  arrow	  up)29 64 Bottom	  Limb34 5 Fold	  Axis 11 52 Foliation	  (CB)11 46 Foliation	  (CB)19 56 Foliation	  (CB)54 5 Axial	  Plane205 22 Axial	  Plane Y Y30 5 Fold	  Axis 21 15 Foliation	  (CB)250 8 Foliation	  (CB)350 27 Foliation	  (CB)Sketch	  MeasurementsOUTCROP	  #2A66layout	  measurements	  :	  J-­‐K,	  7.9m	  towards	  270;	  K-­‐L,	  4.65m	  towards	  264;	  L-­‐M,	  5.1m	  towards	  309;	  M-­‐N,	  3.7m	  towards	  050;	  N-­‐O,	  2.15m	  towards	  318,	  O-­‐P,	  1.95m	  towards	  327;	  P-­‐Q,	  4.05m	  towards	  354;	  Q-­‐R,	  18.3m	  towards	  004142 5462098 0313259 655 61 21 Foliation	  (CB)58 15 Foliation	  (CB)189 27 Foliation	  (CB) crenulated	  leucocratic	  dyke228 2 Fold	  Axis 235 17 Foliation	  (CB)225 39 Foliation	  (CB)40 58 Foliation	  (CB) Large	  scale	  fold	  -­‐	  top	  limb Y35 31 Foliation	  (CB) top	  limb50 61 Foliation	  (CB) into	  hinge	  area68 87 Foliation	  (CB) almost	  vertical245 76 Foliation	  (CB)MT2C1 335/80	  undersidevertical	  foliation	  w/	  folds	  of	  different	  orientation Y2 60 Fold	  Axis 60 22 Axial	  Plane large	  scale	  fold Y250 7 Limb verging	  NWWalk	  up:	  Took	  samples	  from	  outcrops	  trying	  to	  find	  the	  boundary	  of	  the	  shear	  zone	  and	  the	  amphibolite/paragneiss	  sequence.	  About	  20m	  downhill,	  rock	  becomes	  increasingly	  more	  k-­‐feldspathic	  (see	  samples)215 28 Foliation	  (CB)MT3A 215/28 Compositional	  banding	  dips	  NW214 26 Foliation	  (CB)Offset	  or	  stretched	  veins,	  elongated	  k-­‐spar,	  dipping	  parallel	  from	  horizontal,	  surface	  striking	  084/66 Y215 24 Foliation	  (CB)MT3imuch	  less	  foliated,	  greener,	  more	  like	  rocks	  below,	  top	  of	  shear	  zone?MT3B 095/72 both	  ~2m	  above	  other	  measurements195 39 Foliation	  (CB)195 26 Foliation	  (CB)MT3C 071/54 **sketch	  is	  from	  5A1MT4A1 250/80	  underside98 18 Axial	  PlaneC	  -­‐	  very	  mafic,	  large	  porphyroclasts	  of	  k-­‐spar,	  similar	  to	  outcrop	  #3,	  lots	  of	  intense	  folding,	  pretty	  fractured,	  measurements	  may	  be	  slightly	  off135 4 Foliation	  (CB) B	  -­‐	  verging	  NE YOUTCROP	  #4OUTCROP	  #3OUTCROP	  #2CEast	  end	  of	  Outcrop67305 8 Fold	  Axis 132 21 Axial	  Plane110 27 Axial	  Plane195 16 Foliation	  (CB)236 4 Foliation	  (CB) A	  -­‐	  upper	  right168 20 Foliation	  (CB)MT4A2 232/75153 5461340 0314632 875layout	  measurements	  :	  A-­‐B,	  8.7m	  towards	  180;	  B-­‐C,	  4.6m	  towards	  235;	  C-­‐D,	  17.5m	  towards	  180;	  D-­‐E,	  7.8m	  towards	  215;	  E-­‐F,	  3.7m	  towards	  235232 23 Foliation	  (CB) C	  -­‐	  182 6 Foliation	  (CB) D	  -­‐	  MT4A3 162/84	  undersideE	  -­‐	  126 18 Foliation	  (CB) F	  -­‐	  layout	  measurements	  :	  	  A-­‐B,	  13.5m	  towards	  029;	  B-­‐C,	  5m	  towards154 5458738 0314983 854 MT5A1 034/90 sketch	  on	  page	  18 Y	  -­‐	  on	  page	  18300 4 Fold	  Axis 306 42 Limb295 15 Fold	  Axis 145 30 Axial	  Plane300 4 Fold	  Axis 293 34 Axial	  Plane310 4 Fold	  Axis 274 13 Axial	  Plane310 24 Foliation	  (CB)256 24 Foliation	  (CB)296 30 Foliation	  (CB)MT5A2 041/90296 6 Intersection	  (CB	  &	  Crenulation)322 24 Foliation	  (CB) Y Y298 3 Fold	  Axis155 5459048 0314920 532 cliffs,	  leucocratic	  musc	  +	  scarce	  garnet Y YPhoto	  6A1	  -­‐	  268/85	  -­‐	  plane	  facing	  SSE Y Y156 5460176 0314429 707 213 11 Foliation	  (CB)Photo	  6A2	  -­‐	  274/86	  -­‐	  planbe	  facing	  SSE230 11 Foliation	  (CB) possibly	  shifted?302 4 Axial	  Plane verging	  SE276 22 Foliation	  (CB)MT6A2 230/11 shifted	  too??270 11 Fold	  Axis tight	  recumbant	  folds,	  other	  side	  of	  first	  two	  stations YMT6A3 lots	  of	  garnets,	  musc,	  chl,	  qtz,	  plage226 15 Foliation	  (CB)MT6A4 very	  biotite	  richMT6A5 200/85 backside,	  bottom	  of	  clifflayout	  measurements	  :	  40m	  towards	  280;	  20m	  towards	  024OUTCROP	  #6OUTCROP	  #568157 5459961 0314254 641 285 15 Foliation	  (CB)lineations	  almost	  parallel	  to	  strike,	  quite	  massive,	  very	  little	  foliation,	  bands	  and	  possibly	  rafts	  of	  mafic	  biotite	  rich	  rocks,	  more	  foliated,	  leucocratic	  material	  >	  95%MT7A1 280/1572 11 Foliation	  (CB)MT7A2275 39 Foliation	  (CB)large	  outcrop	  of	  leucocratic	  orthogneiss,	  coarse	  grained,	  plage,	  feldspar,	  qtz,	  biotite,	  musc,	  garnet,	  chl	  veinlets	  trending	  N-­‐S	  (almost	  vertical),	  small	  pegmatitic	  dykes	  following	  foliation125 10 Foliation	  (CB)120 11 Foliation	  (CB)110 Lineation MT8A1 Horizontal	  (arrow	  towards	  2703-­‐5cm	  thick	  qtz	  veins	  stiking	  110	  also,	  these	  have	  slight	  reaction	  to	  HCl,	  but	  pretty	  sure	  it's	  in	  the	  voids	  &	  grain	  boundaries,	  seems	  pretty	  undefo med,	  very	  large	  garnets	  and	  biotite	  booklets159 5459220 0313786 511 310 83 Faultsteeply	  dipping	  set	  a	  faults	  w/	  3-­‐5cm	  thick	  gouge	  sections,	  my	  sense	  tells	  me	  that	  it’s	  a	  normal	  fault,	  right	  side	  down	  (hanging	  wall),	  no	  visible	  horizons	  to	  see	  offset,	  possibly	  just	  an	  erosional	  slump? YOUTCROP	  #8OUTCROP	  #769SampleTrend Plunge Rake Strike Dip Type Strike	   Dip Trend Plunge Strike Dip Strike Dip Strike	   Dip Strike dipMT1D 180 86 198 78 108 9 5 10MTZ1F 21 87MT2B2 16 57 280 18 338 86 260 12 190 20 102 86MT2C1 335 80 325 79MT3A 332 34 215 28 C.Banding 63 80 163 90MT3C 140 25 C.BandingMT4A2i 290 10 281 6 C.Banding 26 84 305 10 172 15MT4A3 162 84 276 11 109 6 C.Banding 15 80 284 12 41 15 102 80MT5A1 282 9 210 87 300 3 269 9 105 79MT6A2 6 5 230 11 C.Banding 280 90 196 88MT7A1 99 4 281 15 C.Banding 192 90 284 89MT8A1 Horiz.	  Arrow	  -­‐-­‐>	  270 270 0 260 89Cut	  PlaneOrientation Lineation	  PlanePlane	  Perp	  LineationLineation Foliation Profile	  Plane Fold	  Axis Axial	  Plane70Geologist Easting Northing Strike Dip TrendDave	  Nutall 314680 5458850 280 4 FoliationDave	  Nutall 314620 5458850 92 9 FoliationDave	  Nutall 314225 5458800 285 18 FoliationDave	  Nutall 314125 5458850 315 14 FoliationDave	  Nutall 313990 5458825 222 10 FoliationDave	  Nutall 313990 5458850 285 14 FoliationDave	  Nutall 314150 5458925 283 8 FoliationDave	  Nutall 314075 5458950 275 10 FoliationDave	  Nutall 314150 5459120 274 9 FoliationDave	  Nutall 314150 5459170 315 15 FoliationDave	  Nutall 314160 5459225 262 7 FoliationDave	  Nutall 313990 5459240 286 9 FoliationDave	  Nutall 314020 5459290 302 11 FoliationDave	  Nutall 314460 5459340 117 15 FoliationDave	  Nutall 314130 5459450 285 19 FoliationDave	  Nutall 313995 5459450 264 14 FoliationDave	  Nutall 313020 5459520 157 10 FoliationDave	  Nutall 314040 5459560 242 16 FoliationDave	  Nutall 314040 5460090 235 8 FoliationDave	  Nutall 314220 5460110 237 6 FoliationDave	  Nutall 314050 5460240 257 13 FoliationDave	  Nutall 314140 5460250 288 9 FoliationDave	  Nutall 314050 5460360 260 7 FoliationDave	  Nutall 314560 5461125 137 15 FoliationSean	  Gregory 314740 5458640 314 9 FoliationSean	  Gregory 314750 5458700 305 20 FoliationSean	  Gregory 314625 5458710 12 13 FoliationSean	  Gregory 314130 5458860 285 15 FoliationSean	  Gregory 314290 5458980 124 15 FoliationSean	  Gregory 313960 5458840 289 23 FoliationSean	  Gregory 314100 5459100 120 16 FoliationSean	  Gregory 314040 5459275 175 15 FoliationSean	  Gregory 314325 5459325 163 4 FoliationSean	  Gregory 314800 5459450 238 20 FoliationSean	  Gregory 314030 5459625 130 20 FoliationSean	  Gregory 314530 5460005 139 12 FoliationSean	  Gregory 313980 5460405 266 20 FoliationSean	  Gregory 314580 5460650 114 15 FoliationSean	  Gregory 314530 5460725 134 20 FoliationSean	  Gregory 314450 5461125 185 22 FoliationKate	  Jillings 314560 5458710 285 8 Foliation71Kate	  Jillings 314660 5458850 186 10 FoliationKate	  Jillings 314750 5458850 264 2 FoliationKate	  Jillings 314775 5458925 319 12 FoliationKate	  Jillings 314725 5458980 288 17 FoliationKate	  Jillings 314120 5458795 232 8 FoliationKate	  Jillings 314100 5458840 301 8 FoliationKate	  Jillings 314080 5458970 102 16 FoliationKate	  Jillings 314340 5459030 240 11 Axial	  PlaneKate	  Jillings 314260 5459220 83 4 FoliationKate	  Jillings 314440 5459040 202 23 FoliationKate	  Jillings 314130 5459340 123 7 FoliationKate	  Jillings 314405 5459380 240 2 FoliationKate	  Jillings 314025 5450430 165 8 FoliationKate	  Jillings 314510 5459260 235 3 FoliationKate	  Jillings 314750 5459175 125 10 FoliationKate	  Jillings 314540 5459460 140 31 FoliationKate	  Jillings 313980 5459550 60 13 FoliationKate	  Jillings 314120 5459560 154 8 FoliationKate	  Jillings 314290 5459625 23 16 FoliationKate	  Jillings 314230 5459980 129 8 FoliationKate	  Jillings 314390 5459900 169 18 FoliationKate	  Jillings 314460 5459820 220 4 FoliationKate	  Jillings 314800 5459600 210 8 FoliationKate	  Jillings 314925 5459940 152 12 FoliationKate	  Jillings 314040 5460080 152 2 FoliationKate	  Jillings 313990 5460250 162 2 FoliationKate	  Jillings 313950 5460425 187 3 FoliationKate	  Jillings 314300 5460225 112 9 FoliationKate	  Jillings 314340 5460300 128 6 FoliationKate	  Jillings 314510 5460330 186 14 FoliationKate	  Jillings 314480 5460440 110 3 FoliationKate	  Jillings 314680 5460350 133 3 FoliationKate	  Jillings 314710 5460225 164 1 FoliationKate	  Jillings 314710 5460680 276 20 FoliationKate	  Jillings 314825 5460725 220 4 FoliationKate	  Jillings 314625 5460940 285 62 Axial	  PlaneKate	  Jillings 314225 5460600 134 1 Foliation72Geologist Easting Northing TrendToRotatePlunge TypeDave	  Nutall 314680 5458850 284 10 Mineral	  LineationDave	  Nutall 314160 5459225 282 4 Mineral	  LineationDave	  Nutall 314460 5459340 284 6 Mineral	  LineationSean	  Gregory 314325 5459325 286 5 Mineral	  LineationSean	  Gregory 314530 5460005 271 10 Mineral	  LineationSean	  Gregory 314580 5460650 293 10 Mineral	  LineationSean	  Gregory 314530 5460725 222 5 Mineral	  LineationKate	  Jillings 314560 5458710 288 8 Mineral	  LineationKate	  Jillings 314660 5458850 290 2 Mineral	  LineationKate	  Jillings 314750 5458850 292 9 Mineral	  LineationKate	  Jillings 314725 5458980 287 6 Mineral	  LineationKate	  Jillings 314120 5458795 295 12 Mineral	  LineationKate	  Jillings 314080 5458970 275 5 Mineral	  LineationKate	  Jillings 314260 5459220 285 8 Mineral	  LineationKate	  Jillings 314440 5459040 290 0 Mineral	  LineationKate	  Jillings 314405 5459380 290 4 Mineral	  LineationKate	  Jillings 314025 5450430 213 7 Mineral	  LineationKate	  Jillings 314510 5459260 310 10 Mineral	  LineationKate	  Jillings 314750 5459175 286 3 Mineral	  LineationKate	  Jillings 314540 5459460 270 16 Mineral	  LineationKate	  Jillings 313980 5459550 270 16 Mineral	  LineationKate	  Jillings 314120 5459560 288 6 Mineral	  LineationKate	  Jillings 314290 5459625 294 12 Mineral	  LineationKate	  Jillings 314230 5459980 277 1 Mineral	  LineationKate	  Jillings 314390 5459900 248 12 Mineral	  LineationKate	  Jillings 314800 5459600 299 5 Mineral	  LineationKate	  Jillings 314925 5459940 296 12 Mineral	  LineationKate	  Jillings 314040 5460080 295 1 Mineral	  LineationKate	  Jillings 313990 5460250 292 1 Mineral	  LineationKate	  Jillings 314300 5460225 287 2 Mineral	  LineationKate	  Jillings 314510 5460330 291 10 Mineral	  LineationKate	  Jillings 314480 5460440 290 8 Mineral	  LineationKate	  Jillings 314680 5460350 292 4 Mineral	  LineationKate	  Jillings 314710 5460225 284 1 Mineral	  LineationKate	  Jillings 314710 5460680 276 4 Mineral	  LineationKate	  Jillings 314825 5460725 300 8 Mineral	  LineationKate	  Jillings 314225 5460600 279 6 Mineral	  Lineation73MT1D - FOLD AXIS PLANE 74MT1D - PROFILE PLANE 75MT2B2 - FOLD AXIS PLANE 76MT2B2 - PROFILE PLANE 77MT3A-leuco - LINEATION PLANE 78MT3A-melano - LINEATION PLANE 79MT4A2i - LINEATION PLANE 80MT4A2i - PROFILE PLANE 81MT4A3 - LINEATION PLANE 82MT5A1 - LINEATION PLANE 83MT5A1 - PROFILE PLANE (long limb) 84MT5A1 - PROFILE PLANE (short limb) 85MT7A1 - LINEATION PLANE86MT7A1 - Perpendicular to Lineation PLANE87MT9A1 - PROFILE PLANE8884108MT1D - FOLD AXIS (LINEATION) PLANE (PPL)0.5 cmLm8984108MT1D - FOLD AXIS (LINEATION) PLANE (XPL)0.5 cmLm90MT1D - PROFILE PLANE (PPL)S 0/S178198S 29178198MT1D - PROFILE PLANE (XPL)S 0/S1S 29285069MT2B2 - FOLD AXIS PLANE (PPL)9385069MT2B2 - FOLD AXIS PLANE (XPL)9486338MT2B2 - PROFILE PLANE (PPL)S0/S1Sm/S29586338MT2B2 - PROFILE PLANE (XPL)S0/S1Sm/S2SM9690163MT3A - LINEATION PLANE (PPL) - LeucocraticTop to the RightS29700163MT3A - LINEATION PLANE (XPL) - LeucocraticTop to the RightS29890163MT3A - LINEATION PLANE (PPL) - MelanocraticLm9990163MT3A - LINEATION PLANE (XPL) - MelanocraticLm10082120MT4A2i - FOLD AXIS (LINEATION) PLANE (PPL)Lm10182120MT4A2i - FOLD AXIS (LINEATION) PLANE (XPL)Lm10284026MT4A2i - PROFILE PLANE (PPL) - Fold HingeSm10384026MT4A2i - PROFILE PLANE (PPL) - Fold HingeSm10484026MT4A2i - PROFILE PLANE (PPL) - Stretched Limb10584026MT4A2i - PROFILE PLANE (XPL) - Stretched Limb10680102MT4A3 - LINEATION PLANE (PPL)Top to the Right10780102MT4A3 - LINEATION PLANE (XPL)Top to the Right10880015MT4A3 - PROFILE PLANE (PPL)Sm10980015MT4A3 - PROFILE PLANE (XPL)Sm11079105MT5A1 - LINEATION PLANE (PPL)Lm11179105MT5A1 - LINEATION PLANE (XPL)Lm11287210MT5A1 - PROFILE PLANE (PPL) - Long Limb11387210MT5A1 - PROFILE PLANE (XPL) - Long Limb11487210MT5A1 - PROFILE PLANE (PPL) - Short Limb11587210MT5A1 - PROFILE PLANE (XPL) - Short Limb11689284MT7A1 - LINEATION PLANE (PPL)Top to the Left11789284MT7A1 - LINEATION PLANE (PPL)Top to the Left11890192MT7A1 - PLANE Perp. to LINEATION (PPL)11990192MT7A1 - PLANE Perp. to LINEATION (PPL)120MT8A1(WL14-18) - Random Orientation (PPL)121MT8A1(WL14-18) - Random Orientation (XPL)12266284MT9A1- PROFILE PLANE (PPL)12366284MT9A1- PROFILE PLANE (XPL)12421345679?5450018130251109585102511511210194417212440395911438102617261511424820174515113416594621304311547351522318491062111013109204208616142013374181229168 1861515832038915916163141529174710238141920212238 151315121272414153111820128100101416851216124210652131081254841016596117A005450550700650 006800750550900850900550500450550550550550800800750700650600500550500500700650600850800750600550650500550900700650600850800750550500500500500500500850700650600 550500800 750900900900900900900700650600550500450850800750A’500 mXMT9A1XMT1DXMT2B2 XMT3AXMT4A2iXMT4A3XMT5A1XMT6A1XMT7A1XMT8A15461000N 312500EGreen LakeDiego’s FaultOkanagan Valley Detachment Fault6 ptCzMWSCovert Farms Winery PLATE 1CC’B’BRattlesnake LakeMt. KeoganXOriented Sample LocationXMT1DMain Foliation 15Axial Plane 15Fold Axis15Mineral Lineation15Lithostratigraphic contactBody of waterInferred Fault (Unknown displacement)?Normal Fault (Unknown displacement)Outcrop Outline#Okanagan Valley Detachment Fault (tick on downthrown side) Map LegendRock Type Mylonite ClassicationFine grained, nely banded, weakly chloritized, quartz-plagioclase-K-feldspar-hornblende +garnet+biotite+sphene+epidote+zircon+carbonate) schistFault Breccia - clasts comprising hangingwall and footwall rocksCenozoic rocks of the Marron, White Lake &Skaha Formations  (hanging wall) Ultramylonite (>90% dynamicallyrecrystallized matrix)Intercollations of: (i) coarse to ne grained, felsic and mac banded schlieren of granite to monzogranite+apatite+monazite+zircon; and (ii) granite sheets. Mylonite (50-90%) to ultramylonite (>90% dynamically recrystallized matrix)with relict porphyroclasts of K-feldsparRattlesnake Lake intrusive/pluton - Coarse grained leucocratic, garnet (<1%)-biotite(<5%) granite sheetMedium grained, biotite-hornblende quartz-monzonite to quartz-monzodiorite and ne grained diorite +epidote+sphene+zirconMedium grained, white marbleProtomylonite (10-50% dynamicallyrecrystallized matrix)Protomylonite (10-50% dynamically recrystallized matrix)Protomylonite (10-50% dynamically recrystallized matrix)MKrlOkanagan Valley Detachment FaultCzMWSGLmcMKicMKqmMKwmPALEOZOICCENOZOICOkanagan Valley Shear ZoneGreen Lake metasedimentary complex: Mt. Keogan intrusive complexGLmcGLmcMKwmMKwmMKwmMKqmMKqmMKqmMKicMKicMKicMKicMKrlMKrl*** darker shade of colour represent areas that have been ground truthed.Geologic Map of Mt. Keogan Field Area, Oliver, British ColumbiaMap Projection: UTM NAD1983              Created by Moses Towell, April, 2015 

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.52966.1-0053621/manifest

Comment

Related Items