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Investigation of some physical and chemical properties of the stony marine clays in the lower Fraser… Ahmad, Nazeer 1955

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INVESTIGATION OF SOME PHYSICAL AND CHEMICAL PROPERTIES OF THE STONY MARINE CLAYS IN THE LOWER FRASER VALLEY AREA OF BRITISH COLUMBIA by NAZEER AHMAD A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN AGRICULTURE in the Department of SOIL SCIENCE We accept th i s thesis as conforming to the standard required from candidates for the degree of MASTER OF SCIENCE IN AGRICULTURE. Members of the Department of S o i l Science THE UNIVERSITY OF BRITISH COLUMBIA October 1955 INVESTIGATION OF SOME PHYSICAL AND CHEMICAL PROPERTIES OF THE STONY MARINE CLAYS IN THE LOWER FRASER VALLEY AREA OF BRITISH COLUMBIA ABSTRACT Some of the physical and chemical properties of the stony marine clays recently described by Armstrong and Brown i n the Lower Fraser Valley area of B r i t i s h Col-umbia were investigated. Mechanical analysis of samples taken from four depths from the Murrayville, Jackman and Lehman s i t e s showed that the amount of clay material less than 2 microns in diameter increased from a range of 4 to 18 per cent i n the surface foot to 20 to 40 per cent at a depth of 18 feet. The s i l t and fine sand material varied conversely, the surface foot containing from 77 to 96 per cent while the material from; 18 feet contained from 61 to 68 per cent. The textural c l a s s i f i c a t i o n of the samples ranged from sandy loam to s i l t loam i n the surface, and from loam to clay loam at depth. The material collected from the fourth s i t e , Haney, had a somewhat higher content of clay material, 42 to 46 per cent, and a smaller percentage of coarse skeleton, fine sand and s i l t . Samples from the surface were not available, but the textural c l a s s i f i c a t i o n at depth was clay to s i l t y clay. The mechanical analysis and other — 2— physical and chemical information support the suggestion that the material at the Haney s i t e d i f f e r s s i g n i f i c a n t l y from that at the others. The apparent and re a l densities of the material at a l l four sites increased with depth, the range i n ap-parent density being from about 1.1 to 1.4 at the surface to 1.4 to 1.8 at 18 feet. In the case of the r e a l density the range was from about 2.69 on the surface to 2.74 to 2.82 at depth. There was a corresponding reduction i n t o t a l porosity from about 60 per cent of the s o i l volume at the surface to 35 per cent at depth. The moisture ten-sion determinations showed that to a large extent this re-duction was at the expense of large or macro pores. Hydraulic conductivity determinations with s o i l cores showed that close to the surface the material i s reasonably permeable to water, but that i t decreases to a very low value at depth. The cation exchange capacity of the material was found to vary considerably ranging from 7 to 23 m i l l i -equivalents per 100 gm. In general the deeper samples gave somewhat lower and more constant values than the surface, ranging from 10.2 to 16.5 m i l l i - e q u i v a l e n t s per 100 gm. Reaction and exchangeable cation determinations showed that at the one-foot depth the material i s acid, pH 5.0 to 5.8, and from 40 to 73 per cent base saturated. However, the reaction and degree of base saturation was found to increase with depth u n t i l i n the deeper samples the reaction ranged from pH 7.4 to 9.4> and the clay mat-e r i a l was completely base saturated. Highly s i g n i f i c a n t quantities of exchangeable sodium and free lime were found i n a l l the deep samples. Material with e f f e c t i v e diameter less than 2 microns was separated from a l l samples, and from the 18-foot samples less than .5 micron material as well. The free-oxide content of the less than 2 micron material was found to range from about 8.7 per cent at the surface to 3.9 per cent at depth. Sodium carbonate fusion analysis showed the fine material to contain from 50 to 60 per cent s i l i c a , and have a high silica-sesquioxide r a t i o ranging from 3.02 to 6.41« The fi n e material was found to contain s i g n i f i c a n t l y more t o t a l magnesium and potassium at depth. These results, together with the high exchange capacity and dehydration values obtained suggest that the f r a c t i o n smaller than ,5 microns contains a s i g n i f i c a n t amount of clay material of the montmorillonite, i l l i t e , or hydrous mica types, and that the proportion of th i s material i s somewhat higher at the surface. ACKNOWLEDGEMENTS The writer would l i k e to express his sincere thanks to Dr. C. A. Rowles, Chairman, Department of S o i l Science, The University of B r i t i s h Columbia, for his kind assistance and c r i t i c i s m s during this study, and to Dr. D. G. Laird, Emeritus Professor of the same Department, for words of encouragement and advice. The help rendered by the Dominion S o i l Survey Laboratory and by the Chemistry Division of the B r i t i s h Columbia Research Council i n making certain equipments available to the writer has been very g r a t e f u l l y appre-ciated. The writer also wishes to thank the National Research Council and the Committee on S o i l and Snow Mech-anics whose f i n a n c i a l assistance made the work possible. i i -TABLE OF CONTENTS INTRODUCTION REVIEW OF LITERATURE EXPERIMENTAL A. Location and Description of Sites B. Physical Analyses (1) Determination of Mechanical Composition (2) Density, Porosity, Hydraulic Con-du c t i v i t y and Atterberg Constants (3) Moisture Retention Characteristics C. Chemical Analyses Da The Clay Material (1) Separation of the Clay Material (2) Removal and Estimation of Free Oxide i n the Clays (3) Fusion Analyses of Clay Material Less Than ,002 mm, i n Diameter (4) Cation Exchange Capacity of the Clay Material (5) Dehydration of the Clay Material SUMMARY AND CONCLUSIONS LITERATURE CITED - i i i -LIST OF TABLES Table Page I Mechanical Composition (Per Cent by Weight of Moisture-Free S o i l ) . . 27 II Density, Porosity, Moisture and Air at Sampling 35 III Macro- and Micro-Pore Space, Hydraulic Conductivity and Atterberg Limits 36 IV Moisture Retained at Six Tensions (Per Cent by Weight) . 40 V Organic Matter, Reaction, Sulphates, Chlorides and Carbonates . 46 VI Cation Exchange Capacity, Exchangeable Ca-tions, Total Base and Sodium Saturation 47 VII Free Oxides of Iron, Aluminium, Manganese and Phosphorus Associated with the Clay Material Less Than ,002 mm. (Per Cent of Moisture-Free Material . 57 VIII Sodium Carbonate Fusion Analysis of Clay Material Less Than 2 Microns Diameter (Per Cent of Moisture-Free Clay Material) 64 IX Molecular Ratios of the Clay Material Less Than 2 Microns 65 X Cation Exchange.Capacity of the Clay Mat-e r i a l With and Without Treatment for Re-moval of Sesquioxides 73 - i v -LIST OF FIGURES Following Figure Page 1 Index Map Showing Physiographic Features of Area and Direction of Main Ice Movement • 24 2 Summation Curves for Samples From Murray-v i l l e 30 3 Summation Curves for Samples From Jackman Road 30 4 Summation Curves for Samples From Lehman Road 30 5 Summation Curves for Samples From Haney . 30 6 Summation Curves For S o i l From Lehman Road (1 f t . ) and Jackman Road (18 f t . ) , Com-paring Acid and Hydrogen Peroxide Treatments 30 7 Dehydration Curves f o r Fine Material (Less Than 2 Microns), Murrayville Site 77 8 Dehydration Curves For Fine Material (Less Than 2 Microns), Jackman Road Site 77 9 Dehydration Curves for Fine Material (Less Than 2 Microns), Lehman Road Site 77 10 Dehydration Curves for Fine Material (Less Than 2 Microns), Haney Site 77 11 Dehydration Curves of Fine Material (Less Than .5 Micron) From 18-Foot Depth 77 INTRODUCTION In 1939, Kelly'and S p i l s b u r y completed and pub-l i s h e d a S o i l Survey of the Lower Fraser V a l l e y (46). In t h i s report they described a l a r g e and important area of s o i l i n the general v i c i n i t y of Aldergrove as Whatcom S i l t Loam, but they were able to provide l i t t l e d e t a i l about i t s mode of o r i g i n or the processes of s o i l formation as-soc i a t e d w i t h i t . R ecently, Armstrong and Brown (5) f o l l o w i n g upon e a r l i e r work of Johnston (44) made a d e t a i l e d study of the g e o l o g i c a l processes a s s o c i a t e d w i t h the parent m a t e r i a l of the Whatcom s o i l . They found t h i s m a t e r i a l to be of a very compact, s i n g l e - g r a i n e d s t r u c t u r e , blue-grey i n co l o u r , w i t h stones, cobbles and pebbles (bearing g l a c i a l s t r i a -t i o n s and evidence of marine..1 a c t i o n ) i r r e g u l a r l y d i s t r i b -uted and f i r m l y embedded. They a l s o found marine f o s s i l s , both damaged and w e l l preserved occurred, and that the num-ber increased with depth. On the b a s i s of these and other f e a t u r e s the authors described the formation as a f o s s i l i f -erous stony marine c l a y and concluded that i t was l a i d down by the wasting away and r e t r e a t of a major c o r d i l l e r a n i c e -1-sheet during the Wisconsin g l a c i a l period, when an arm of the sea occupied that portion of the Fraser Valley (44)• In view of the importance of the findings of Armstrong and Brown, i t was decided to i n i t i a t e the present study which, i t was hoped, would supply information that would be of help i n understanding the processes of s o i l formation and the s o i l s associated with the materials des-cribed by them as stony marine clays. REVIEW OF LITERATURE In the s o i l survey of the Lower Fraser Valley, published in 1939, Kelly and Spilsbury described an import-ant s o i l in the general v i c i n i t y of Aldergrove as Whatcom S i l t Loam (46). The detailed description of the s o i l given by these authors was as follows: "The whole of the Whatcom series was mapped as Whatcom S i l t Loam. This type covers a large section of the upland d i s t r i c t , with a total area of about 67>700 acres. The principal area covers about 54,000 acres in the v i c i n i t y of Aldergrove. Smaller areas occur on the Surrey upland and on the north side of the Fraser between Haney and Ruskin. The age and formation of the Whatcom series compares with that of the Alderwood series, but i t is found at lower elevations seldom exceed-ing 400 feet above sea level. The topography consists of h i l l s low and rounded and slopes never steep nor eroded. The area is f u l l of small h i l l s , and depressions that have no general direction; the depressions being poorly drained. There are many of these poorly drained depressions within small areas, which ad-versely affect the growth of crops. The Alderwood and Whatcom series are the two upland soils with restricted sub-drainage. In the Alderwood series the restriction of drainage is due to an indurated sandy boulder clay. In the Whatcom series the material impervious to the downward movement of precipitation water has the general appearance of an ancient post-glacial delta deposit which has become weakly cemented. The Whatcom parent material consists of about one-third each of very fine sand, s i l t and clay, with scattered grit and occasional embedded stones. For the purpose of identification the most important feature is the structure, which i s jointed - 3 --4-and fragmentary. The same structure without any cementation was noted i n the C horizon of the Milner and Haney series, which are obviously p o s t - g l a c i a l r i v e r deposits. It i s concluded that the Whatcom series i s probably the oldest p o s t - g l a c i a l delta deposit to be formed under approximately the same delta building process that i s now going on at the mouth of the Fraser r i v e r . The average depth of the Whatcom parent mat-e r i a l i s unknown. During the survey only one cut was found which exposed the i n t e r g l a c i a l gravels that l i e beneath. In t h i s case the thickness of material was about four feet, but the l o c a t i o n was too close to the boundary of another s o i l type to have any s i g n i f i c a n c e . In the Whatcom series the problem of farm water supply i s similar to that i n the Alderwood serie s . Surface water from the top of the imper-vious parent material i s the most probable source. The weakly cemented parent material i s the cause of the high watertable and should be studied care-f u l l y before land drainage i s undertaken. The surface topography of the Whatcom series follows more or less f a i t h f u l l y the topography of the impervious sub-stratum. When a well i s to be dug, a certain amount of prospecting should be done to ascertain the correctness of t h i s theory in the given area, so that the well may be located where there w i l l be an adequate supply of water free from barnyard contamination. A p r o f i l e description of Whatcom S i l t Loam i s as follows:-Horizon Depth Description Ao 0-1" Dark brown organic forest l i t t e r . A3 1-12" Reddish-brown s i l t loam, f i n e l y granular, loose, open, with many concretions. Occasional small stone or gravel. A^ 12-20" Pale reddish-brown, yellowish-brown to grey-brown loam or clay loam, massive and dense, iron staining but no iron concretions. Horizon Depth Description Loam or clay loam, grey and iron stained. Transition to the C 2 horizon. Parent material weakly cemented, impervious to water, drab grey, iron stained at the top. Angu-l a r fragmentary structure, dense and hard, somewhat tough when wet. Scattered f i n e g r i t and embedded stones. Clay loam to clay texture. The chemical analysis shows that the nitrogen and organic-matter content compares favourably with that i n the better types of upland s o i l s . The t o t a l phosphorus content, while not d e f i c i e n t , i s lower than i n any other s o i l in the Fraser v a l l e y . The movement of minerals i n t h i s s o i l indicates that the process of podsolization has been domin-ant over that of l a t e r i z a t i o n , iron, aluminium, calcium and magnesium having being leached to some extent while s i l i c a has tended to accumulate i n the surface s o i l . Horizon Cj i s the zone of maximum wetness i n t h i s s o i l type. Water moves over the more imper-vious C 2 horizon and f o r t h i s reason drainage t i l e should be i n s t a l l e d on top of t h i s horizon." Johnston (44) i n writing on the geology of the general area described l a t e r by K e l l y and Spilsbury as Whatcom S i l t Loam suggested that at some time during the Pleistocene period, the sea entered the Fraser Valley f o l -lowing the retreat of the ice sheet, and at a l a t e r period of g l a c i a t i o n , the ice sheet ploughed up f o s s i l s from the newly formed sea f l o o r incorporating them into the sedi-C x 20-24" C 2 ment3• At a l a t e r date, Armstrong and Brown ( 5 ) studied the formation i n great d e t a i l . They claim that ice sheets, ori g i n a t i n g from the Canadian Coastal Mountains, wasted away in the Lower Fraser Valley region during l a t e Wis-consin times, depositing t h e i r load of coarse and f i n e materials, i n saline or brackish waters. They proposed that over most of t h i s area there was at f i r s t a c o r d i l -leran ice sheet corresponding to the layer of t i l l under-l y i n g the stony marine clays. This ice sheet gave way to berg and sea ice which floated oyer the area with the ad-vent of warmer conditions, depositing f i n e r materials. During the i n t e r v a l s normal marine sediments were deposited, giving r i s e to layers of u n s t r a t i f i e d g l a c i a l materials, interbedded with layers of s t r a t i f i e d marine sediments. The authors noted the wide d i s t r i b u t i o n of marine f o s s i l s and of stones bearing g l a c i a l s t r i a t i o n s and worn by marine action. They claimed that upon the gradual u p l i f t of the land, the deposited material was subjected to further sort-ing and r e d i s t r i b u t i o n by marine action r e s u l t i n g i n the p i l i n g of coarse material at the tops of pre-existing h i l l s . Armstrong and Brown ( 5 ) described the u n s t r a t i -f i e d stony marine clays deposited from f l o a t i n g i c e as being massive, very compact and impalpable, containing half s i l t and half clay, with scattered cobbles and boulders up to ten inches i n diameter. The normal marine sediments found i n layers showing s t r a t i f i c a t i o n were found to be greasy, impalpable, and interbedded with f i n e sands and s i l t s . Deposits of similar age and history occurs i n Eastern Canada around Lake Champlain and these have been widely studied from a geological point of view (3, 16, 17, 24, 38). F l i n t (38) provided the most comprehensive ideas on the geological history of the area. The old d i v i s i o n s of "Leda" clays i n the lower areas and "Saicava" sand i n the upper areas he discredited since the pelecypods Leda and Saxicava apparently occur i n both members. According to him at least two bodies of marine sediments, separated by an unconformity, occupy the St. Lawrence Lowland, these being Champlain marine deposits and the Ottawa marine deposits. He explained that the Champlain sea which suc-ceeded Lake Vermont i n the Champlain Basin was connected to the A t l a n t i c by the St. Lawrence, and that i t flooded the Lake Ontario Basin and submerged the eastern end of the Trent Valley outlet of Lake Algonquin, a f t e r the ex-t i n c t i o n of Lake Iroquois. From the d i s t r i b u t i o n of the f o s s i l s he explained that the water must have r i s e n against the land to some 700 feet i n the v i c i n i t y of Ottawa, f o l -lowed by subsequent u p l i f t . At t h i s time normal erosion took place before the area was again submerged, t h i s time as the Ottawa Sea. During the f i n a l stages of g l a c i a t i o n the area rose above the l e v e l of the sea, giving r i s e to the well known Ottawa deposits. The s o i l s have been described as being grey i n colour, very impervious, with much a l k a l i n e carbonates. M i l l e r (51) conducted a detailed study of the marine deposits of Middleton Island, Alaska. These might be somewhat older deposits than those of the Fraser Valley, but nevertheless, show a great deal of s i m i l a r i t y . Gen-eral features of the "Conglomeratic Sandy Mudstone" have been described as follows: 1. Contains marine f o s s i l s i n abundance. 2. It i s embedded with, and grades l a t e r a l l y into, s t r a t i f i e d and sorted sediments that are obviously of marine o r i g i n . 3. It forms beds that have f a i r l y regular upper and lower surfaces and that maintain a r e l a t i v e l y constant thickness over a considerable area. -9-According to his description, most of the frag-ments i n the clay to fi n e sand grades are fresh and angu-l a r . The medium sand to gravel grades, on the other hand, range from angular to rounded i n o u t l i n e . He explained the poor sorting of the stones i n the area to the fa c t that the surface of deposition must have been at or above the influence of currents and waves, but protected from t h e i r action by the presence of unstable land areas, shelf ice or berg i c e . Another of his suggestions was that streams of t u r b i d i t y currents may have scoured the sea f l o o r , subjecting the bottom deposits to crude sorting action, or may have contributed sorted sediments from a distant source. Twenhofel (77) made a general survey of the shore l i n e changes along the P a c i f i c Coast of Alaska. He observed that there were innumerable raised beaches, marine terraces, boulder clays, and normal marine clays, a l l bearing marine f o s s i l s , up to an a l t i t u d e of f i v e hun-dred feet above sea l e v e l . The d i s t r i b u t i o n of a l l these f a c i e s , as described, seemed to follow the same pattern as those described by M i l l e r (51) and Armstrong and Brown (5). The f o s s i l s i d e n t i f i e d were of the same nature as those of -10-the Lower Fraser Valley, and are now currently l i v i n g i n the P a c i f i c o f f the Alaskan Coast. Sayles and Knox (65) surveyed the region around Cape Cod i n Massachusetts, which according to t h e i r observa-tions, and those of F l i n t (38) have a similar geological history. According to these workers, the deposits can be divided into two groups, based on stratigraphy, and on l i t h o l o g i c a l and physical differences. 1. An upper sandy t i l l containing many large boulders and pebbles. 2. A lower clayey component - a series of at least three layers of blue clayey t i l l , with a scattering of small boulders and pebbles. Between these two an erosional surface was iden-t i f i e d , consisting l a r g e l y of f i n e grained material, with a high percentage of s i l t s i z e , and a considerable amount of f i n e l y divided mica. They claimed that the upper sandy t i l l contained a large percentage of angular boulders and pebbles, i r r e g -u l a r l y d i s t r i b u t e d , and showing no signs of weathering. In the grey clay layers sub-angular s t r i a t e d , and rounded glaciated pebbles were seen to occur with big boulders, very sporadically d i s t r i b u t e d and incorporated -11-i n a matrix of f i n e material. Cracking was noted to be a feature, down which water entered and brought about some weathering. On examining the so-called clay i t was found to consist c h i e f l y of rock f l o u r , and more of a s i l t than a true clay. In structure, the material was very compact, and sticky when wet. In l i g h t of the very modern explanations of these g l a c i a l events there might have been two major g l a c i a t i o n s , followed by a few minor retreats and readvances. The f i r s t period deposited coarse t i l l underlying the clays, and the clays themselves with small stones and pebbles might have been l a i d down by f l o a t i n g sea ice or icebergs, following the wasting-away of the ice sheet. This was probably f o l -lowed by the l a s t great g l a c i a t i o n which deposited up to 30 feet of t i l l , but with the onset of warmer conditions, currents such as the Gulf Stream might have originated, taking with i t the f i n e r sediments. Perhaps during Wisconsin times g l a c i a l a c t i v i t y was most developed i n Scandinavia, but a limited amount of information about t h e i r action and the r e s u l t i n g depos-i t s i s a v a i l a b l e . Slater (67) surveyed the structure of the deposits of Moens K l i n t , Denmark. From topographical -12-features, he concluded that the area was subjected to some-what disturbed g l a c i a l action, periods of rapid advancement being accompanied by periods of r e t r e a t . He claimed that sections of the d r i f t were in v a r i a b l y obscured by s l i p s , and that the stony clays occurred mostly i n valleys while the h i l l s were capped with a layer of t i l l . Normal marine clays were observed to occur side by side with stony mar-ine clays, and i n borderline cases d i f f i c u l t y was experi-enced in recognizing the two f a c i e s . Near Hjorring, i n North Denmark, similar g l a c i a l deposits were also i d e n t i f i e d by Slater (68) but he recog-nized a somewhat d i f f e r e n t geological history, with cor-responding difference i n the deposits. He described the blue-grey clay as very fine textured, and almost stoneless, and i n some parts homogenious and imperfectly bedded. Slater (69) reviewed the r e s u l t s of g l a c i a l action i n the B r i t i s h I s l e s . His observations were that i n sever-a l parts of England, Scotland, and Ireland, boulder clays occurred i n which there were marine f o s s i l s well preserved, and there was neither lamination nor d i s t i n c t s t r a t i f i c a t i o n of the clays. It was supposed that deposition took place i n shallow water, the l e v e l of the land r i s i n g above the -13-surface when the load of ice was r e l i e v e d , and sinking below the l e v e l of the sea at maximum g l a c i a l periods. This suggestion was put forward because layers of clay with marine f o s s i l s occur with layers of coarser materials free of f o s s i l s . He noted that i n the west coast of Scot-land there was evidence of only one major g l a c i a t i o n , whereas on the Yorkshire coast at least three major gla-ciations took place marked by three layers of stony marine clays bearing f o s s i l s with layers of coarse materials i n between. In the stony clays, rocks from Norway, Scandin-avia, Scotland, and from l o c a l areas occurred. According to Slater, the I r i s h Sea formed a pool, into which Scottish ice poured i n from the north and I r i s h ice from the west, r e s u l t i n g i n very rapid de-position of material; t h i s was followed by retreat of the I r i s h Sea, whose f u l l extent can be traced with certainty by the presence of a c h a r a c t e r i s t i c chocolate coloured foraminiferal boulder clay. In t h i s material the fauna showed a r c t i c and southern deep and shallow water types, a l l confusedly intermingled, and the same species were found at the highest lev e l s as at the lowest, and the same i n boulder clays as in sands and gravels. -14-Slater ( 6 9 ) also noted the occurrence of boulder clays with marine f o s s i l s i n North Wales. De Geer (Antevs, 3) described deposits of the same age occurring i n Sweden* He concluded that g l a c i a l streams ended i n salt or very brackish water, followed by melting and deposition of the transported sediments. He observed that g l a c i a l marine clays were massive in structure, intractable, and contained numerous marine fos-s i l s . He concluded that the stony marine clays were formed when fine mud was spread at, and deposited from, the sur-face of the ocean, and that the varved g l a c i a l clays, when the mud was transported along the bottom. F l i n t (37) conducted an important study compar-ing the stratigraphic sequence within the Wisconsin g l a c i a l stage in America, with those of the newer d r i f t s i n B r i t a i n and those i n continental Europe, i t s presumed equivalents. Radio-carbon studies revealed s t r i k i n g s i m i l a r i t i e s . This constituted a reasonable basis for the b e l i e f that the same sequence of g l a c i a l sub-stages characterized both con-ti n e n t s . It i s therefore l i k e l y that the same series of climatic fluctuations affected both continents simultan-eously during the Wisconsin g l a c i a l age. EXPERIMENTAL A. The Location and Description of Sites The experimental sites were chosen in consulta-tion with Dr. Armstrong of the Canadian Geological Survey. Since sampling was to be done to considerable depth, natural exposures were used. The exposed surfaces were quite fresh, but in each case considerable material was removed and discarded before samples were taken. The cuts used were almost vertical, and presented some d i f f i -culty in obtaining samples, particularly core samples. Bulk samples were taken at the same time, at least ten pounds of s o i l being removed from each depth. Murrayville Site; This site was formed by stream erosion. On f i r s t entering the formation from the lowlands of Langley Prairie the land rises sharply to an elevation of 50 to 75 feet. Drainage water from the village of Mur-rayville as well as from neighbouring areas drain through a channel, down the sides of the steep face, and into a small ravine at the valley bottom. The sides of the valley are sparsely covered with secondary growth. Because of the volume of water flowing down this cut, and the nature of -15--16-th e material, gulley erosion has progressed at a very rapid rate. The following i s a description of the p r o f i l e . 0 - 4 feet 10TR 5/3 brown (dry), 10YR 3/3 dark grey-brown (moist)j surface layer of 4 inches of undecomposed and p a r t l y decomposed l i t t e r j numerous nodules apparently cem-ented with dehydrated iron oxide; roots of trees confined to t h i s layer; stones absent. 4 - 1 0 feet 10YR 7/3 l i g h t grey (dry), 10YR 4/4 dark yellowish brown (moist); formation changes to massive clay which, on drying, reveals columnar structure,-, with units about one foot in height; very e a s i l y erodible; stones almost absent. 10 - 15 feet 10YR 8/1 white (dry), 10YR 6/1 l i g h t grey to grey (moist); cracking occurs but units i r r e g u l a r , and maybe up to one cubic yard i n size; between cracks through which water from the surface has percol-ated, are black encrustations r i c h i n organic matter, iron and manganese. -17-15 feet 5Y 6/1 l i g h t grey to grey (dry), 5Y 4/1 dark grey (moist); non-cracking and very re s i s t a n t to weathering, stones and peb-bles very common, fi r m l y imbedded i n the g r i t t y clay; on drying out material sets very hard and does not change colour on standing i n a i r for considerable length of time; very few f o s s i l s present. Jackman Road; This section resulted from cutting through the top and sides of a h i l l during the laying of an o i l p i p e l i n e . The o r i g i n a l cut has since been much enlarged by stream erosion. The p r o f i l e was described as follows: 0 - 3 feet 5YE 5/4 reddish brown (dry), 5YR 3/3 dark reddish brown (moist); very s i l t y with nodules; stones absent. 3 - 8 feet 10YR 8/2 white (dry), 10YR 6/3 pale brown (moist)j massive; columnar structure on drying with units 6" - 8" i n height; stones not v i s i b l e . 8 - 1 1 feet 10YR 8/2 white (dry), 10YR 6/3 pale brown (moist); very massive; cracking occurs on drying with fragments irr e g u l a r and sometimes of great size; black encrustations between cracks. -18-11 - 12 feet Pronounced band of coarse material from 5" to 1 f t . i n thickness; 10YR 7/2 l i g h t grey (dry), 10YR 6/1 grey (moist); stones occur up to s i x inches i n diameter showing rounded edges; i n f i l material mostly of gravel to coarse sand i n s i z e . 12 feet 5Y 7/1 l i g h t grey (dry), 5Y 5/1 grey (moist); very compact with small stones i r r e g u l a r l y d i s t r i b u t e d . G l a c i a l T i l l Material taken from the lower end of the cut and consisting of p a r t i c l e s almost e n t i r e l y of coarse sand grade. Lehman Road; At the crest of a flat-topped h i l l along Lehman Road there i s a road cutting about 50 yards long, along which the material i s exposed. The elevation i s about 100 to 150 feet. According to Armstrong and Brown's conclusions (5) t h i s must have been a marine t e r -race when the area was being elevated above sea l e v e l . A description of t h i s section i s as follows: 0 - 2 feet 10YR 6/4 l i g h t yellowish brown (dry), 10YR 3/4 dark yellowish brown (moist); abund-ance of rounded and subangular stones -19-and pebbles i n a matrix of f i n e sand, s i l t and clay; granular structure, 2 - 4 feet 10YR 8/2 - 7/2 l i g h t grey (dry), 10YR 6/8 brownish yellow (moist)j same as above but with less stones, 4 - 8 feet 1GYR 7/2 l i g h t grey (dry), 10YR 5/4 y e l -lowish brown (moist); massive, showing columnar cracking; stones uncommon, 8 - 1 4 feet 10YR 8/2 white (dry), 10YR 5/3 brown (moist) cracking i n i r r e g u l a r pattern, with black encrustations between cracks; stones up to 3" i n diameter very infrequently d i s -t ributed. 14 feet 10YR 8/1 white (dry), 10YR 6/1 grey (moist); massive, and sets hard on drying; non-cracking, with stones and small boulders up to 9" i n diameter very i r r e g u l a r l y d i s t r i b u t e d . Haney; The fourth s i t e was at Haney Brickyard and the s o i l here d i f f e r s in many ways from the other three (6) s i t e s described. Armstrong/suggests that t h i s s i t e repre-sents a border-line between stony marine clays and normal -20-marine clays. The occurrence of stones i s very rare, about one i n every cubic yard. Nevertheless, stones are present, and they exhibit g l a c i a l s t r i a t i o n s and evidences of marine action. About 200 feet from the sampling s i t e there i s a deposit of coarse t i l l , which more or less re-lates the whole formation i n t h i s area to the stony marine clays of the Lower Fraser Valley. F o s s i l s separated from the s o i l of t h i s s i t e are the same as those found i n other parts of the region, and Armstrong suggests that only the occasional iceberg might have floated over the s i t e , depos-i t i n g the occasional stone, and during the i n t e r v a l s , nor-mal marine sediments were deposited, r e s u l t i n g i n the observed s t r a t i f i c a t i o n and the predominance of fi n e p a r t i -c l e s . The o r i g i n a l surface s o i l was removed by the Brick Company as being u n f i t for the making of t i l e s . What i s now the surface was formerly at a depth of s i x feet or so. The p r o f i l e can be described as follows: 0 - 6 feet Removed, not sampled. 6 - 1 1 feet 10YR 7/4 very pale brown (dry), 10YR 5/4 yellowish brown (moist); stones and nodules absent. 11 - 21 feet 5Y 6/1 l i g h t grey to grey (dry), 5Y 4/1 dark grey (moist); massive, f r a c t u r i n g M O U N T A I N ; * / / B R I T I S H C O L U M B I A / /_ . , W A S H I N G T O N V . FIGURE 1.—INDEX M A P SHOWING PHYSIOGRAPHIC FEATURES OF A R E A AND DLRECTION OF M A I N ICE MOVEMENT Arrows indicate generalized direction of ice movement Armstrong and Brown (4) ), Sites Sampled. 1 . Jackman Road, 2 . Murrayville, 3 . Lehman Road, 4 . Haney. -21-i n regular columns, about one foot i n height; f o s s i l s abundant. 21 - 31 feet 5Y 6/1 l i g h t grey to grey (dry), 5Y 4/1 dark grey (moist); f r a c t u r i n g i n i r -regular blocks, f o s s i l s abundant. 31 feet 5Y 6/1 l i g h t grey to grey (dry), 5Y 5/1 grey (moist); beds of s i l t y clay about nine inches thick, separated by thin layers ( 1 - 2 mm.) of white s i l t . A map showing the physiographic features of the area and main ice movement with the experimental si t e s located i s presented below. B. Physical Analyses ( l ) Determination of Mechanical Composition The mechanical analyses were conducted using several methods of dispersion and the Bouyoucos type A hydrometer. The hydrometer c a l i b r a t i o n and c a l c u l a t i o n of p a r t i c l e sizes from the hydrometer readings were made ac-cording to the method of Day (26) (27). In t h i s method the e f f e c t i v e depth, or the point of the suspension where the density i s equal to that recorded on the hydrometer stem, i s found on the assumption that the density gradient -22-i n the suspension cylinder follows a logarithmic function as proved by Puri (54), Codoni (22) (23), and Day (26). Previously Casagrande (15) assumed a l i n e a r r e l a t i o n be-tween depth and density in his c a l i b r a t i o n , and Thoreen (71) evolved an a r b i t r a r y factor i n his attempt, for the same purpose. In the laboratory the samples were f i r s t a i r - d r i e d , crushed, mixed and sieved through a 2 mm. sieve. The coar-ser f r a c t i o n was weighed as the coarse skeleton of the s o i l . F i f t y gram portions of the sieved s o i l were weighed to t •02 gm», and placed in 600 ml. beakersj to t h i s was added about 100 ml. of d i s t i l l e d water, and a f t e r mixing with a glass rod, 10 ml. of 30 volumes per cent hydrogen peroxide were introduced. The beaker was then covered with a watch glass and placed on the steam bath at medium heat, where oxidation of the organic matter took place. With surface s o i l s r e l a t i v e l y r i c h i n organic matter, 5 ml. of hydrogen peroxide were added at f i r s t , and the beaker kept at room temperature for six hours or so before placing on the steam bath. This was done to prevent frothing over. In cases where excessive frothing took place i n spite of the precautions, a few drops of propyl alcohol subsided i t . - 2 3 -Digestion was continued u n t i l the supernatant l i q u i d i n the beaker became clear and there was no v i s i b l e decompos-i t i o n of hydrogen peroxide. For subsoils about 25 ml. of the 30 volume per cent hydrogen peroxide was s u f f i c i e n t , added over a period of one day, but in the case of surface 1 s o i l s as much as 50 ml. had to be used, with at least two days for digestion. Eight r e p l i c a t e s of each sample were used and afte r the hydrogen peroxide treatment they were s p l i t into two groups of four each. Of the f i r s t group, one pair was used to estimate loss on hydrogen peroxide treatment, and the other, for mechanical a n a l y s i s . With the second set, two were used for estimation of loss on acid t r e a t -ment, and the other for mechanical analysis a f t e r acid treatment. Acid treatment p r i o r to mechanical analysis was achieved by adding to the hydrogen peroxide treated s o i l 300 ml. of approximately .2 N hydrochloric acid, and a l -lowing the mixture to react for one hour with frequent s t i r r i n g . In the case of subsoil material with free c a l -cium carbonate, an a d d i t i o n a l 5 ml. of hydrochloric acid was added for each per cent calcium carbonate above 2 per cent. The s o i l was f i l t e r e d using a Buchner funnel f i t t e d -24-with a 7 cm. Whatman No. 50 f i l t e r paper, and washed with three 60 ml. portions of acid, during which process the s o i l was completely transferred from the beaker to the f i l t e r . Leaching was continued with d i s t i l l e d water u n t i l the f i l t r a t e emerged free of chloride ions, as detected by the s i l v e r n i t r a t e t e s t . At t h i s point two of the four portions of s o i l so treated were reserved for loss on acid treatment, and the other two, together with those kept from the hydrogen peroxide treatment, were dispersed for mechanical an a l y s i s . Dispersion for mechanical analysis was very c a r e f u l l y done since Black ( 9 ) i n a special study of the hydrometer method stressed i t s importance, and recent recommendations by Day (26, 27) were followed in develop-ing the procedure outlined below. The s o i l from the f i l t e r paper i n the case of the acid treatment, or from the beaker with the hydrogen peroxide treatment, was quan t i t a t i v e l y transferred to a small rubber stopper b o t t l e , and the volume made up to 150 ml. with d i s t i l l e d water. Ten m i l l i l i t e r s of a 10 per cent solution of "Calgon""'* was added as dispersing 1 "Calgon" i s the trade name of sodium hexametaphos-phate to which.enough sodium carbonate has been added to form a well buffered solution. -25-agent, the bottle placed in a horizontal position on a reciprocating shaker and shaken over night. Then the s o i l was transferred to a Bouyoucos dispersion cup and f i l l e d to three-quarters with d i s t i l l e d water. This was s t i r r e d by means of the machine for exactly f i v e minutes, where-upon the r e s u l t i n g suspension was transferred to a l i t r e cylinder and made to that volume with d i s t i l l e d water. The cylinder was put i n a temperature bath at about 67° F. and l e f t for about two hours to a t t a i n equilibrium. The suspension was then completely mixed by withdrawing the cylinder from the bath and s t i r r i n g the contents by means of the mechanical brass s t i r r e r , or by turning the cylinder end over end using the palm of the hand as a stopper. Im-mediately upon the cessation of. s t i r r i n g the timer was set and the cylinder returned to the bath. The f i r s t reading was taken a f t e r 40 seconds.of sedimentation, and thereafter at three-minute inter v a l s u n t i l f i f t e e n minutes, at h a l f -hourly i n t e r v a l s u n t i l two hours, followed by readings at three, f i v e , ten, f i f t e e n , twenty and twenty-five hours. Although these times were a r b i t r a r i l y chosen, they provided enough points to plot a representative summation curve, re-l a t i n g size of p a r t i c l e s to per cent of s o i l . Before finding the e f f e c t i v e depth, the hydrometer readings were -26-corrected for temperature and dispersing agent according to Day (26). In applying Stokes 1 equation to calculate p a r t i c l e sizes a s p e c i f i c gravity of 2.75 was used for the s o i l p a r t i c l e s as t h i s value was found by experiment-ation to be more r e a l i s t i c than the value of 2.65 f r e -quently assumed. The sand i n the dispersed sample was separated by passing the suspension through a 300 mesh sieve at the conclusion of the hydrometer readings, and a l l sand i n the cylinder was washed into the sieve. The s i l t and clay was removed by washing, and the sand transferred to a small beaker and oven dried. It was then fractionated by passing through a nest of sieves of the following mesh sizes: 20 (840 microns), 40 (420 microns) 60 (250 microns), 140 (105 microns). Each f r a c t i o n was weighed and the v a l -ues incorporated i n the accumulation curve. The results of the mechanical.analyses are shown in Table I and Figures 2 to 6. It w i l l be noted from these that although mechanical analysis was performed on both the samples acid and non-acid/treated, only two r e s u l t s by the acid treatment are included, the one-foot depth from the Lehman s i t e , and the 18-foot depth from the Jackman Road. The TABLE I: MECHANICAL COMPOSITION (Per cent by weight of moisture-free s o i l ) Coarse Depth 01' - . \_ Skeleton 2mm* Coarse Sand Grade 2—.2mm. Fine Sand "Grade .2-.02mm. S i l t Grade .02-.002mm. Clay Grade .002mm. Texture 1 Class Murrayville 1 - 26.0 56.0 18.0 S i l t loam 8 0.1 - 10.0 66.0 24.0 S i l t loam 12 1.8 4.0 32.0 36.5 28.5 Loam 18 2.1 2.5 27.5 34.0 36.0 Clay loam Jackman Road l i - 62.0 34.0 4.0 Sandy loam 6 - 13.0 67.0 20.0 S i l t loam 10 0.8 - 28.7 33.9 28.4 Clay loam 11| 28.0 50.5 33.3 13.7 2.5 Sand 18 1.8 • - 26.0 42.5 20.5 Loam G l a c i a l _ T i l l 2.0 84.0 12.0 2.5 1.5 Sand Lehman Road 1 22.1 6.5 55.5 21.5 16.5 Sandy loam 3 12.2 10.0 34.5 34.0 21.5 Loam 6 1.4 3.0 33.0 35.0 29.0 Clay loam 12 1.8 4.0 32.0 36.0 28.0 Clay loam 18 2.1 - 26.0 35.0 39.0 Clay loam Haney 46.0 7 2.0 10.0 42.0 S i l t y clay 17 - 8.0 48.0 44.0 S i l t y clay 27 - 10.0 40.0 50.0 Clay 37 - 14.0 40.0 46.0 Clay 1 U.S.D.A. S o i l Survey Manual, U.S.D.A. Handbook No. 18, 1951. -28-r e s u l t s for these two samples were similar to those ob-served in the other s o i l s , and i n general the acid t r e a t -ment increased the weight of p a r t i c l e s less than #002 mm. in diameter by 3 to 5 per cent. Returning again to Table I and Figures 2 to 6, and considering the mechanical composition of the f i r s t three s i t e s i n r e l a t i o n to depth, i t w i l l be noted that the material close to the surface was found to contain d i s t i n c t l y l e s s f i n e material than depth. Thus, the mat-e r i a l from approximately one foot contained from 4 to 18 per cent of p a r t i c l e s less than .002 mm. in diameter, whereas the 18-foot depth material was found to contain from 20.9 to 39 per cent. Considering further the surface material, i t w i l l be noted that i t was found to consist mainly of fin e sand, 26 to 62 per cent, and s i l t , 21.5 to 56 per cent, the texture grade ranging from sandy loam at the Jackman Road and Lehman Road sit e s to s i l t loam at the Murrayville s i t e . When the material from greater depth, correspond-ing more cl o s e l y to that described by Armstrong and Brown (5) as stony marine clay, i s studied i t w i l l be noted that -29-i t too contains a s i g n i f i c a n t but smaller percentage of fin e sand and s i l t , the ranges at the 18-foot l e v e l for the f i r s t three s i t e s being from 26 to 27.5 per cent of fin e sand and 34 to 42.5 per cent of s i l t . Considering the ranges of sand, s i l t and clay obtained for a l l the stony marine clay samples below s i x feet, i t w i l l be noted that with the exception of the Haney s i t e , the texture designation range from loam to clay loam. Attention i s also directed to the percentage of coarse skeleton; i . e . , p a r t i c l e s larger than 2 mm. i n diameter shown i n Table I. It w i l l be noted that i n gen-e r a l the percentage of coarse skeleton found i n the samp-les/of stony marine clay was small, ranging from 0 to 22.1 per cent, and that no p a r t i c l e s larger than 2 mm. were found in the samples from the Haney s i t e . It w i l l also be noted that the percentages of coarse sand were also low in the samples. In the Jackman Road s i t e two layers were sampled which were d i s t i n c t l y d i f f e r e n t from that described as stony marine clay. One of these occurred at a depth of 11 to 12 feet and the other below the 18-foot depth. It w i l l be noted from Table I that the layers contained a - 3 0 -great deal more coarse, and less f i n e material than the stony marine clay, the textural c l a s s i f i c a t i o n i n both layers being found to correspond to sand. The mechanical analysis r e s u l t s for the Haney s i t e are of p a r t i c u l a r i n t e r e s t . Due to the fact that the surface s o i l had been removed i t could not be sampled, but from the depths obtained the samples gave a much higher percentage of f i n e material, much higher than for the other three s i t e s . Thus, the clay material, less than .002 mm., ranged from 44 to 50 per cent and the s i l t from 42 to 48 per cent. The t e x t u r a l c l a s s i f i c a t i o n was found to range from s i l t y clay to clay. The mechanical analysis r e s u l t s support the sug-gestion that the material at the Haney s i t e was derived in a somewhat di f f e r e n t way from that of the other s i t e s ( 6 ) . The lower clay content i n the surface layers of these s o i l s also suggests that weathering does not appear to have s i g n i f i c a n t l y increased the quantity of f i n e tex-tured material, and that the mechanical analysis found i s cl o s e l y related to that of the material as deposited. -31-The mechanical analysis r e s u l t s for the Murray-v i l l e , Jackman and Lehman s i t e s also seem to support the suggestion made by Armstrong and Brown (5) that on the up-l i f t of these areas coarser materials were p i l e d by waves at the h i l l t o p s * (2) Density, Porosity, Hydraulic Conductivity and Atterberg Constants For the determination of apparent density, por-o s i t y and hydraulic conductivity samples respresenting as nearly as possible undisturbed s o i l conditions were re-quired, and for t h i s purpose a thin-walled sampling t o o l was used to c o l l e c t s o i l cores (60)* The cores were of three-inch inside diameter and length, and were taken i n t r i p l i c a t e . In the f i e l d they were placed i n moisture-proof containers and transferred to the laboratory where they were trimmed flush at the ends and weighed immediately, and one end covered with a muslin cloth held i n place with e l a s t i c . They were then allowed to saturate with water by placing them i n larger pans and slowly r a i s i n g the water-l e v e l i n the pan u n t i l i t was f l u s h with the top of the core but not flooding i t . In the case of the surface cores -32-sa.turation was complete i n about two days, but i n the case of the samples from depth as much as two weeks was required. When saturation was complete the cores were removed and a l -lowed to drain momentarily and then weighed. From t h i s weight the saturation porosity was l a t e r calculated. The cores were then placed on a Tension Table of the type developed by Learner and Shaw as described by Smith ( 7 0 ) and allowed to come to equilibrium at a tension of 40 cm. The weight of water removed at th i s tension was used to calculate the macro-pore space of the s o i l . After weighing the moist cores were again satur-ated and used for the estimation of hydraulic conductivity under a constant head equivalent to .5 inches of water. In calculating the hydraulic conductivity the well-known Darcy's equation was employed i n the form given below and appropriate units used so that the r e s u l t s were expressed i n inches per hour. Q „ K £ 2 L ^ 2 a L where Q = volume of outflow hj « distance from reference l e v e l to top of water head h 2 s distance from reference l e v e l to bot-tom of s o i l column - 3 3 -A « area of s o i l L = length of s o i l column K = hydraulic conductivity The conductivity tests were continued u n t i l water transmission reached a constant rate and the cores were then a i r - d r i e d and f i n a l l y dried to constant weight ; i.-„ at 105° C. The dry weight of the s o i l was used to calcu-l a t e the apparent s p e c i f i c gravity and moisture content of the s o i l as i t came from the f i e l d . The oven dry s o i l was f i n a l l y removed from the cores and a f t e r crushing and sieving a sample was withdrawn from each for the determination of r e a l s p e c i f i c gravity following method E -9 i n the Earth Manual, published by the United States Bureau of Reclamation ( 7 8 ) . From the appar-ent and r e a l s p e c i f i c gravity values the t o t a l pore space was calculated using the formula below: Per cent Pore Space = 1- apparent s p e c i f i c gravity x 1 Q Q r e a l s p e c i f i c gravity The Atterberg l i q u i d and p l a s t i c l i m i t s were determined using sub-samples taken from the bulk samples af t e r crushing and mixing. The actual procedures used were Designations 4 2 3 - 3 9 and D424-39 of the Procedures for Testing S o i l s of the American Society for Testing Materials - 3 4 -( 2 ) . In the case of Designation 4 2 3 - 3 9 , however, a modi-f i e d grooving t o o l was used. The r e s u l t s of the physical tests described above are included i n Tables II and I I I . From the res u l t s included i n Table I I , i t i s evident that a marked and rather regular increase in ap-parent s p e c i f i c gravity was found with increasing depth, the range being from about 1 . 2 at the surface to about 1.8 at 18 fe e t . The surface values may be considered normal for surface s o i l s and the higher values i n the deeper lay-ers are in d i c a t i v e of greater compaction. The r e a l s p e c i f i c gravity values were also found to be generally higher at depth. In the surface few feet, the r e a l s p e c i f i c gravity figures were closer to the aver-age value of 2 . 6 5 frequently used i n connection with s o i l material. The higher values, 2 . 7 2 to 2.82, found at depth suggest the presence of a di f f e r e n t d i s t r i b u t i o n of miner-als and a higher proportion of the heavier type. The saturation porosity decreases with depth as in the case of the apparent s p e c i f i c gravity values. Read-ings of 3 0 to 40 per cent pore space found i n the subsoils are very low when compared to 5 0 to 6 0 per cent i n the TABLE I I : DENSITY, POROSITY, MOISTURE AND AIR AT SAMPLING Depth ( f t . ) Apparent Specific Gravity Real Spe c i f i c Gravity Total Pore Calculated % by -volume ' Space Saturation % by volume Moisture % by volume A i r % by volume Murrayville 1 1.14 2.69 57.5 55.6 26.5 29.1 8 1.39 2.74 49.0 38.4 37.2 11.8 12 1 . 6 0 2.78 42.5 36.2 39.4 3.1 18 1 . 6 0 2.77 42.3 35.9 37.9 4.4 Jackman Road •Ik 1.08 2.69 6 0.0 59.7 Not determined 6 1.25 2.75 54.5 52.8 Not determined 10 1.61 2.76 41.6 38.6 Not determined nk _ 2.80 - - • Not determined 18 1.65 2.79 41.0 36.5 Not determined G l a c i a l T i l l - 2.79 - - Not determined Lehman Road - 1 1.41 2.69 47.5 49.9 19.4 28.1 3 1.38 2.71 48.7 48.1 20.2 28.5 6 1.68 2.75 38.9 39.4 20.8 18.1 12 1.67 2 . 7 6 39.5 39.7 21.4 18.1 18 1.86 2.82 33.9 33.8 19.1 14.8 Haney 65.5 36.8 7 1.14 2.69 58.5 21.7 1 7 1.35 2.81 51.8 43.0 47.6 4.2 2 7 1.39 2.75 50.4 38.5 43.4 7.0 37 1.43 2.79 49.5 36.0 40.6 8.9 TABLE I I I : MACRO- AND MICRO-PORE SPACE, HYDRAULIC CONDUCTIVITY AND ATTERBERG LIMITS Depth ( f t . ) Macro-pore Space % by volume Micro-pore Space % by volume Hydraulic Conductivity ins.per hr. Liquid Limit % by weight P l a s t i c Limit % by weight P l a s t i c Index Murrayville 36.3 34.1 10.2 °1 19.3 1.2 42.3 8 4.5 33.9 * - 39.4 32.9 6.5 12 3.8 32.4 * - 37.8 27.0 10.8 18 2.6 33.3 * - 38.6 24.3 14.3 Jackman Road 20.4 39.3 1.2 39.6 31.1 8.5 6 8.6 44.2 * - 36.8 30.7 6.1 10 4.6 34.0 - 40.3 25.6 14.7 11* — - -No data - - -18 3.5 33.0 - 39.8 23.8 16.0 G l a c i a l T i l l - - No data - - -Lehman Road 1 10.6 37.6 .3 22.6 17.5 5.1 3 8.8 39,3 .3 24.1 19.6 4.5 6 5.5 33.9 * - 39.8 24.5 15.3 12 4.5 34.2 - 38.5 28.3 10.2 18 3.2 30.6 * - 39.3 23.4 15.9 Haney 33.6 7 14.6 50.9 .2 42.8 9.2 17 2.4 40.6 * - 43.7 32.3 11.4 27 2.4 36.1 * - 44.0 33.8 10.2 37 — 36.0 * — 43.2 32.5 10.7 * Too small to measure. -37-surface materials, which i s more c h a r a c t e r i s t i c of normal s o i l s . This fact further emphasizes the compact nature of the subsoils. From Table III i t w i l l be noted that except at Lehman Road the deeper s o i l s were almost completely satur-ated with water at sampling, showing that conditions were nearly anaerobic. At Lehman Road the exposure was per-haps several years old at sampling, and apparently insuf-f i c i e n t material was discarded p r i o r to sampling to make the samples t r u l y representative of the normal condition at depth. The s o i l appears to have had enough time to dry out, which would account for the higher a i r content at time of sampling. The hydraulic conductivity r e s u l t s i n general vary inversely with the macro-pore' space, the values being reasonably high i n the surface but extremely low i n the samples from depth. These very low hydraulic conductivity values would suggest that downward movement of water must indeed be slow. However, i t should be r e c a l l e d that the structure i n the f i e l d provided for some cracks or chan-nels between st r u c t u r a l aggregates and the laboratory tests may not have f u l l y evaluated water movement through these - 3 8 -spaces. Therefore, the hydraulic conductivity i n the f i e l d may be somewhat higher than indicated by the laboratory tests, though i t i s not thought the difference can be very great. Considering the low hydraulic conductivity v a l -ues for the deep samples, together with t h e i r low a i r con-tent, i t must be concluded that whatever chemical weather-ing takes place must take place l a r g e l y under anaerobic conditions. ( 3 ) Moisture Retension Characteristics The amount of moisture retained by the s o i l mat-e r i a l s was determined at s i x d i f f e r e n t tensions ranging from zero to 3 0 . 5 atmospheres. The zero tension corres-ponded to saturation and was found using the s o i l cores as previously described. For the next higher tension, corresponding to 4 0 cm. of water, pF 1 . 5 , s o i l cores we/re also used and the tension applied using the Learner and Shaw Tension Table as described previously. The moisture equivalent determination was used for the t h i r d tension l e v e l using crushed s o i l from the bulk samples, the actual procedure followed being Designation 4 2 5 - 3 9 of the American Society for Testing Materials ( 2 ) . The tension corres-ponding to the moisture equivalent was taken as pF 2,5 as suggested by Bayer ( 8 ) . The pressure pot apparatus and method as described by Richards (57) was used to obtain one atmosphere, pF 3• The pressure membrane apparatus and method as described by Richards (56) was used to give the 15 atmosphere tension, pF 4 . 2 . The highest tension used was 30,5 atmospheres or pF 4.5* This tension was obtained by the hygroscopic c o e f f i c i e n t as described by Baver ( 8 ) . The moisture retained by the s o i l materials at these tensions i s given i n Table IV. The moisture retention, data are shown i n Table IV. It i s obvious that the water holding capacity i s influenced by the clay content, the type of clay min-e r a l , the amount of organic matter present, and the amount of porosity in the aggregates. Except for the surface, organic matter and aggregation are both absent, so that in these cases moisture retention properties are governed by the f i r s t two fa c t o r s . In the surface, organic matter undoubtedly plays an important r o l e i n retaining moisture, since the clay content i s not very high. This i s -40-TABLE IV: MOISTURE RETAINED AT SIX TENSIONS (Percent by Weight) Moisture Tensions Expressed as pF \» AX ( f t S ) 0 1.5 2.5 3.0 4.2 4.5 Murrayville 1 55.6 3 9 . 3 28.8 2 4 . 7 17.0 4.3 8 38.4 34.2 28.3 23.4 13.5 4.2 12 3 6 . 2 33.8 26.7 23.2 14.6 3.7 18 35.9 32.0 21.8 17.3 9.9 2.8 Jackman Road 59.7 49.2 29.4 24.9 9.4 5.1 6 5 2 . 8 49.5 42.4 34.8 9.5 4.5 10 38.6 34.3 29.6 25.0 1 3 . 3 4.3 ii4 - 36.5 29.3 24.6 11.6 1.8 18 36.5 3 6 . 3 29.4 24.8 12.7 3.3 G l a c i a l T i l l - - - - -Lehman Road 1 49.9 22.8 17.0 14.9 10.1 3.4 3 48.1 28.6 19.8 16.6 11.2 2.8 6 39.4 31.6 24.5 22.1 14.7 3.0 12 39.7 32.6 24.9 22.5 15.8 3.1 18 33.8 2 9 . 1 2 4 . 6 20.7 13.9 2.7 Haney 7 65.5 48.6 4 0 . 2 36.7 24.8 8.2 17 43.0 40.1 37.4 31.9 15.6 3.2 27 38.5 37.6 36.3 3 0 . 5 15.9 3.4 37 36.0 35.5 3 1 . 0 2 7 . 1 14.2 2.4 -41-p a r t i c u l a r l y so i n the Jackman Road s i t e . As w i l l be pointed out l a t e r , the clay minerals at the surface of these s i t e s must be of a high moisture retaining nature, and t h i s might also contribute. It w i l l be noted that the subsoils are richer i n clay and therefore capable of higher moisture retaining capacities at higher tensions. On comparing the re s u l t s with those published by Baver ( 8 ) and Robinson ( 6 2 ) , the moisture holding cap-a c i t i e s are somewhat higher up to three atmosphere tension for the corresponding texture i n the case of the deeper s o i l s , while the surface s o i l s behaved normally i n t h i s respect. At higher tensions, however, the r e s u l t s are quite i n accord with the textures recorded. The hygroscopic moisture values are quite con-stant for a l l the s i t e s at a l l depths, with the surface showing some differences. In these re s u l t s experimental errors due to differences i n atmospheric humidity are re-duced to a minimum since the analyses for hygroscopic mois-ture were done for a l l the s o i l s at about the same time. Since the hygroscopic moisture i s usually associated with the c o l l o i d a l f r a c t i o n of the clay these r e s u l t s might - 4 2 -indicate that the c o l l o i d a l f r a c t i o n of the samples i s much more constant than the clay content according to the mechanical analyses reported, which varies greatly from sample to sample. C. Chemical Analysis Chemical analysis of the s o i l s include reaction (pH), cation exchange capacity, the exchangeable cations potassium, sodium, calcium, magnesium, and the anions s u l -phate, chloride, and carbonate. Reaction or pH measurements were made on a sat-urated s o i l paste using a Beckman Model N pH meter, and organic matter was found according to the wet combustion method of Walkley and Black (80). For the cation exchange capacity determination a modified Schollenberger procedure (66) was adopted for leaching the s o i l , and a 2 N solution of neutral ammonium acetate was prepared according to Piper (53) and used as the leaching solution. A 25 gm. sample of a i r - d r i e d s o i l less than 2 mm. i n size was placed i n the leaching column previously loosely plugged with cotton. Five hundred m i l l i l i t r e s of -43-the 2 N ammonium acetate was then leached through, using gentle suction at the end to remove the excess. The s o i l was washed free of unadsorbed ammonium i o n B by passing 2 G 0 ml. of 9 5 per cent ethyl alcohol through the column. The ammonium s o i l and cotton wool were then transferred to a large Kjeldahl flask with d i s t i l l e d water, and the volume made up to about 3 0 0 ml. A piece of p a r a f f i n wax was added to prevent foaming on d i s t i l l a t i o n . Enough 10 N sodium hydroxide was added to the flask to give a t o t a l concentration of .1 N, and the adsorbed ammonium ions were displaced by steam d i s t i l l a t i o n and collected i n a known volume of standard .1 N hydrochloric a c i d . D i s t i l l a t i o n was continued for about one-half to three-quarters of an hour, afte r which the unneutralized a c i d i t y was estimated by t i t r a t i n g with standard sodium hydroxide. Blanks were done i n the same way using untreated s o i l . From the t i t r a -t i o n values the cation exchange capacity of the s o i l was calculated, with corrections being made for the a i r - d r i e d moisture content of the sample. At the commencement of these studies, potassium was estimated i n the extracts gravimetrically with sodium phenyltetraboron (40). The aliquot ( 2 5 ml.) of ammonium - 4 4 -acetate extract used for potassium determination was f i r s t c a r e f u l l y treated to remove ammonium ions, by evaporating to dryness with aqua regia. The residue was taken up with 1 ml. of concentrated hydrochloric acid, and the volume made up to 50 ml. Ten m i l l i l i t r e s of 1.5 per cent sodium phenyl-tetraboron solution was added slowly with s t i r r i n g , and the beaker allowed to stand for a few minutes before f i l -t e r ing through a tared sintered glass c r u c i b l e . After drying for 3 0 minutes at 1 1 0 ° C. the pr e c i p i t a t e was weighed as potassium phenyltetraboron. Potassium was afterwards estimated on a Perkins-Elmer flame spectrophotometer ( 5 9 ) . A large number of potassium determinations by the two methods using both known and unknown solutions showed good agreement. For sodium the gravimetric method using sodium uranylzinc acetate ( 5 3 ) was f i r s t used, followed l a t e r by the flame spectrophotometer (59)» As for potassium t r i a l determinations by the two methods give s a t i s f a c t o r y agreement• In order to estimate calcium and magnesium, the versenate method of Cheng and Bray ( 2 0 ) was employed a f t e r satisfactory checks were obtained between t h i s and standard -45-gravimetric procedures. The ammonium acetate extract was evaporated to dryness with aqua regia and the residue taken up with d i s t i l l e d water. Interfering cations were complexed with sodium diethyldithiocarbonate, and separated (21). F i n a l l y the calcium and magnesium were estimated by t i t r a t i o n with standard sodium versenate (di-sodium s a l t of ethylene diamine t e t r a - a c e t i c a c i d ) , separate aliquots being used for each. The sulphate content was determined by precip-i t a t i o n as barium sulphate a f t e r evaporating an aliquot of the ammonium acetate extract to dryness and digesting the residue with aqua regia (53)» Carbonate was estimated gravimetrically using 10-gram samples of the s o i l (59)• Chloride was determined by t i t r a t i n g an aliquot of the ammonium acetate extract with standard mercuric n i t r a t e (59). In Tables V and VI are shown the results of the chemical analyses of the s o i l s . Organic matter i s high on the surface, but drops to n e g l i g i b l e values with depth. Due to the nearly anaero-bic conditions existing i n the deeper layers, roots of plants are la r g e l y confined to the surface. In such a case organic matter can be dis t r i b u t e d through the s o i l TABLE V: ORGANIC MATTER, REACTION, SULPHATES, CHLORIDES AND CARBONATES Depth ( f t . ) Organic Matter Reaction SO^ = (pH) mi l l i - e q u i v a l e n t s CI- 003= m i l l i - e q u i v a l e n t s /100 gm. Murrayville 1 5.76 5.7 8 0.116 6.0 12 0.203 6.9 18 0.294 7.4 Jackman Road l i 4.38 5.8 6 0.27 5.7 10 0.17 6.9 l l j 0.07 6.4 18 0.51 7.6 G l a c i a l T i l l 0.15 6.7 0.005 0.007 0.15 0.46 Trace 0.03 0.18 Trace 0.45 Trace Trace Trace 0.05 0.05 Trace Trace .008 .003 .05 Trace 2.68 21.48 3.42 22.24 i i Lehman Road 1 1.72 5.6 3 0.17 5.5 6 0.27 5.8 12 0.06 6.5 18 0.25 7.7 Trace Trace Trace 0.29 0.56 Trace Trace Trace .004 .07 1.64 20.60 Haney 7 13 27 37 3.64 0.14 0.08 0.19 5.0 9.4 9.1 9.1 Trace 1.96 1.48 1.29 Trace 0.05 0.19 0.16 46.36 37.23 31.45 TABLE VI: CATION EXCHANGE CAPACITY, EXCHANGEABLE CATIONS, TOTAL BASE AND SODIUM SATURATION (Milli-equivalents/lOO gnu s o i l ) Base Na* Depth Exchange Q a + + M N A + K4- Saturation Saturation ( f t . ) Capacity P e r C e n t p e r C e n t Murrayville 1 23.45 13.83 2.02 0.79 0.53 73.4 .04 8 24.48 14.26 5.99 1.74 0.48 92.4 .71 12 12.51 - - 1.97 0.89 100.0 15.70 18 11.83 - - 4.09 0.63 100.0 34.80 Jackman Road i4 19.64 5.42 2.40 0.03 0.48 42.5 .02 6 20.92 7.64 ' 5.99 0.42 0.48 71.4 2.0 10 13.34 - - 1.84 0.56 100.0 13.8 n4 8.67 4.70 2.28 0.79 0.38 94.4 9.1 18 13.35 - - 3.96 0.59 100.0 29.8 G l a c i a l T i l l 6.82 3.46 2.72 0.05 0.40 97.7 .07 Lehman Road 1 7.42 3.68 1.72 0.005 0.42 79.4 .07 3 10.37 4.51 2.26 0.07 0.18 67.9 .09 6 17.67 9.37 4.96 0.62 0;82 89.4 3.5 12 16.56 10.29 6.21 0.74 0.74 100.0 4.7 18 11.35 - - 3.72 1.45 100.0 32.8 Haney 1 10 20 30 27.89 12.32 11.34 10.24 8.00 11.62 0.13 3.50 6.94 4.96 0.66 0.97 1.54 1.34 73.0 200.0 100.0 100.0 .4 28.3 61.2 48.6 -48-c h i e f l y by percolating water. However, i t has already been pointed out that the downward movement of water i s r e s t r i c t e d as a re s u l t of the compact structure. In the intermediate layers organic matter i s confined to the black encrustations l i n i n g the walls of the cracks which are the only avenues for water movement. Besides being r i c h i n organic matter, the black encrustations are also r i c h i n iron and manganese, occurring probably as organic complexes. The reaction of the s o i l down the p r o f i l e s i s of prime i n t e r e s t . The surface i n every case i s very acid, denoting a leached condition. The pH increases r a p i d l y with depth, reaching a l k a l i n e conditions i n the blue-grey clay at the 18-foot depth, the actual values ranging from 7 , 4 to 7 » 7 i n the f i r s t three s i t e s , but at Haney i t i s over 9»0. The variations i n pH indicate an unsaturated condition of the clay in the surface to a base saturated condition i n the deeper horizons, which i s v e r i f i e d by the experimental r e s u l t s . In normal s o i l forming processes, the deeper layers are usually enriched with cations and anions at the expense of the surface s o i l s . In t h i s case, these contribute l i t t l e , i f any, to the high values ob-served i n the deeper layers, since the bulk of the percolating - 4 9 -water from the surface has been observed to move horizon-t a l l y over the impervious materials than through them. The only conclusion i s that the entire p r o f i l e s were completely saturated with cations at the beginning of s o i l formation, but the surfaces were depleted due to weathering and leach-ing while the subsoils remained untouched. Anions increase with depth, with carbonates reaching high values i n the subsoils. Most of the free calcium and magnesium found i n these regions probably oc-cur as carbonates. It i s rather surprising that the v a l -ues for sulphates and chlorides are not higher than those recorded. In t h i s connection the suggestion of Johnston (44) i s of i n t e r e s t , that i n the f i n a l stages of g l a c i a -t i o n i n these areas, the water was very d i l u t e ; calcium and magnesium which form, more insoluble carbonates than potassium and sodium must have accumulated i n the pro-f i l e s as carbonates, with sodium and potassium being leached out as sulphates and chlorides. In addition, calcium and magnesium having higher ionic a c t i v i t i e s than sodium and potassium, would have replaced these to a large extent on the exchange complex at the time of deposition. This would offe r some explanation to the low values of sodium, potassium, sulphate and chloride observed i n these -50-s o i l s . Sodium, the dominant cation in sea water, must have influenced the position i n the exchange reactions described, for in one case at Haney, as much as 61 per cent of the base exchange capacity i s taken over by sod-ium, and i n the other s i t e s 29 to 34 per cent. In the surface, of course, conditions have been greatly modified by leaching, with sodium and potassium being removed, but calcium and magnesium having greater a f f i n i t y for the clay, remaining to a greater extent. In the deeper s o i l s at Haney i t i s l i k e l y that some sodium might be present as sodium carbonate, since calcium and magnesium carbonates cannot alone be respon-si b l e for the high pH readings ranging from 9*1 to 9.4» The exchange capacity of the s o i l s follow cer-t a i n d e f i n i t e trends. In the surface the organic matter and clay contents are the dominating features. Thus, Haney, with the highest clay content, has the highest cation-exchange capacity, with Murrayville having r e l a t i v e l y high clay content and organic matter coming next. At Jack-man Road the observed cation-exchange i s quite high when i t i s considered that the material only has 3 per cent of clay. However, i t has the highest percentage of organic matter and this might explain the high value. The si t e at -51-Lehman Road has the lowest organic matter content on the surface, and i t i s also low i n clay; consequently the cation-exchange capacity i s low. On the whole, the cation-exchange capacities of the surface materials are considered high, es p e c i a l l y when considered with the low clay contents. This fact indicates the presence of high cation-exchange clay minerals. In the subsoils the exchange capacity i s not as varied as on the surface, and much less per unit of clay; whatever v a r i a t i o n occurs, i s not necessarily related to the differences in clay content. This might suggest either some p a r t i c l e s , although of clay dimension, do not neces-s a r i l y possess base-exchange properties, or the actual cation-exchange capacity of the clay i s l e s s than i n the surface. D. The Clay Material It was decided that i n studying the stony marine clays some attempt should be made to determine the nature fin e clay of the_/material. In order to do t h i s i t was necessary to separate some of the fin e material from the s o i l s . The procedure was to separate t h i s f r a c t i o n and examine i t as described below. -52-(1) Separation of the Clay Material In order to separate the clay f r a c t i o n of the s o i l , a 100 gm. portion l e s s than 2 mm. i n size was f i r s t treated with hydrogen peroxide for removal of organic mat-ter, then dispersed by means of a Bouyoucos machine for about 10 minutes, using 20 ml. of 10 per cent !'Calgon" solution as dispersing agent. The suspension produced a was poured into_/sedimentation cylinder: which was; f i l l e d to the litre-mark with d i s t i l l e d water. After thorough mixing either by inverting the cylinder a number of times on the palm of the hand, or by the use of the manual brass s t i r r e r , i t was allowed to stand i n a constant temperature bath at approximately 67° F. for about 20 hours, when, ac-cording to Stokes 1 Law a l l p a r t i c l e s larger than 2 microns i n size would have settled past 25 cm. At t h i s time the cylinder was c a r e f u l l y removed from the bath and the sus-pension siphoned off to a depth of about 25 cm. This was then concentrated by heating on a sand bath at medium heat, and brought to dryness on a steam bath. The clay thus obtained was crushed i n a clean porcelain mortar, sieved through a 150 mesh sieve, and stored i n small screw capped b o t t l e s . r Because of the high clay content of most of the material examined, only one separation per sample was necessary to y i e l d enough clay for a l l future determination's. -53-However, i n some cases the procedure had to be repeated two or more times to obtain a f a i r supply of clay. (2) Removal and Estimation of Free Oxides in the Clays The oxides of aluminium, iron, phosphorus, etc. are known to be deposited on the surface of c o l l o i d a l clay, and i n order to expose the true surface these com-ponents must be removed. It has been recognized that the cleaning up of the clay p a r t i c l e s by suitable techniques when properly carried out allows sharper X-ray photographs to be taken, increases the base exchange capacity, and does not destroy the clay minerals ( l , 31* 52, 6 3 ) . Most available methods (31, 28) employ reducing or complex forming organic reagents, but since these have to be destroyed before using any colorimetric pro-cedure for the determination of iron or aluminium, a com-p l e t e l y inorganic procedure would be more u s e f u l . Dros-dorf ( 3 2 ) , Drosdorf and Truog (33) and Toth ( 7 5 ) employed hydrogen sulphide, but t h i s compound i s somewhat objection-able i n the laboratory. Sodium bis u l p h i t e was t r i e d by Brammal and Leech ( 1 3 ) , but on comparison with other methods (52), t h i s proved very i n e f f i c i e n t . Sodium thiosulphite - 5 4 -was used by Galabutskaya and Govorova (39 ) , and a f t e r examining a l l available methods Mackenzie (49) concluded that t h i s was superior. Deb (28) and A g u i l l e r a and Jack-son (1) used the same reagent for extraction, but i n ad-d i t i o n employed organic reagents f o r complexing of the iron, aluminium, etc. M i t c h e l l and Mackenzie (52) modified the sodium thiosulphite procedure for treating the clays, but they worked with very small quantities of material. Since i t was desired not only to estimate the free sesquioxide con-tent of the clay f r a c t i o n , but also to obtain enough treated clay for cation-exchange determinations, fusion analysis, and dehydration experiments, the method had to be modified to a certain extent. Two grams of f i n e l y powdered clay were put i n 250 ml. centrifuge tubes, 30 ml. of d i s t i l l e d water added and the tube placed i n b o i l i n g water f o r 20 minutes, with occasional s t i r r i n g . Into a dry volumetric f l a s k was weighed 8 gm. of sodium thiosulphite and t h i s dissolved i n 200 ml. d i s t i l l e d water. The solution was made to pH 6 by adding enough of 1 N sodium hydroxide solution, which was predetermined. This was added to the centrifuge tube containing the clay suspension, and afte r s t i r r i n g with a glass rod, i t was placed i n water kept at 40° C. for 30 minutes, with occasional s t i r r i n g . The suspension was centrifuged, and the supernatant kept i n a beaker. This was followed by 20 ml. of .05 N hydrochloric acid, and aft e r mixing and incubating at 40° C. for 10 minutes with occasional s t i r r i n g the tube was again centrifuged, and the supernatant stored i n another beaker. The treatment with sodium thiosulphite and hydrochloric acid were re-peated in exactly the same manner, the supernatants being added to the respective beakers. The clay was f i n a l l y ex-tracted with 200 ml. of 1 N^sodium chloride solution, cen-tri f u g e d , and the supernatant added to the hydrochloric acid beaker. Further washings with alcohol were carried out to remove any s a l t s , and these washings discarded. After peroxidation of the thiosulphite extract, the s o l -utions were combined, f i l t e r e d through a Whatman No. 30 f i l t e r paper, and made up to one l i t r e with d i s t i l l e d water. Iron and aluminium determinations on the extract were done by the spectrophotometric method of Davenport ( 25 ) , using ferron reagent (8 - hydroxy - 7 - iodo - 5 - quinoline sulphonic acid) for complexing of the iro n and aluminium. - 5 6 -Ferron forms coloured compounds with both iron and alum-inium, each having i t s optimum transmittance at d i f f e r e n t wavelengths. The small aliquot used for determination was f i r s t neutralized with d i l u t e ammonium hydroxide using para-nitrophenol as indicator before adding the reagent. Phosphorus was estimated photometrically accord-ing to the ammonium molybdate method of Truog (76) i n which the phosphomolybdate complex was reduced to lower oxides of molybdenum with stannous chloride. The photometric permanganic method involving potassium periodate (64) was u t i l i z e d for manganese determinations. The re s u l t s of the free oxide determinations are included i n Table VII. It w i l l be noted that the t o t a l free oxides on the surface i s higher, ranging from 7.11 to 8.69 per cent, expressed on oven-dried basis than at depth, and these results are normal for clays according to results obtained by Dion (31) and M i t c h e l l and Mackenzie ( 5 2 ) . With depth the values decrease, i n some cases being half or less than on the surface. Iron drops considerably with depth, and so does phosphorus, while the drop i n aluminium and mangan-ese i s not as great. r 5 7 -TABLE VII: FREE OXIDES OF IRON, ALUMINIUM, MANGANESE AND PHOSPHORUS ASSOCIATED WITH THE CLAY MATERIAL (Per Cent of Moisture Free Material .002 mm.) Depth ( f t . ) Total Free Oxides Fe 2 03 - % A 1 2 0 3 % Mn203 % P2O5 % Murrayville 1 8.27 3 .85 2.41 0.28 1.73 8 5.55 2.75 1.68 0.28 0 . 8 4 12 4 .44 1.82 1.70 0.28 0.64 18 4.45 1.39 1.70 0.37 0.99 Jackman Road lh 7.H 2.75 2.64 0.18 1.54 6 5.40 2.35 2.28 0.25 0.52 10 5.13 2.14 2.02 0.21 0.76 H i 4 .58 1.23 2.20 0 .36 0.79 18 4 . 8 9 1.42 2.17 0.37 0.93 G l a c i a l T i l l 6 . 0 4 4.54 0.48 0.16 0.86 Lehman Road 1 8.09 3 . 6 4 2.52 0.31 1.62 3 6.45 3.18 2.18 0.29 0.80 6 5.69 2.87 1.97 0.26 0.59 12 4 .69 1.94 1.84 0 . 3 0 0 .61 18 4 .64 1.44 2.05 0.28 0.87 Haney 7 8.69 4 . 3 8 2.46 0.28 1.57 17 5.69 3.16 1.73 0.15 0.65 27 5.59 3.03 1.78 0.19 0.59 37 3.87 1.54 1.63 0.18 0.52 - 5 8 -When rocks are weathered the chemical constitu-ents are freed and while most of i t i s incorporated i n the c r y s t a l structure of the secondary clay minerals, some remain free, and occur i n the s o i l as free oxides. Only t r i - v a l e n t oxides tend to accumulate i n the s o i l s under normal circumstances; however, since the others are more soluble, and so removed by leaching. It i s obvious, there-fore, that the free oxides present i n a s o i l or clay i s an indicat i o n of the degree of weathering, showing i n t h i s case that surface i s much more weathered than the subsoils. In cases where the reaction of the s o i l s are not a l k a l i n e , as i n the surface, the.free phosphorus would be associated with i r o n . In the a l k a l i n e s o i l s at lower depths, on the other hand, i t i s more probable that alum-inium phosphates might be present, es p e c i a l l y at the s i t e at Haney, where the reaction i s very a l k a l i n e . The occurrence of free iron i s e a s i l y seen from the colour changes down the p r o f i l e . In the surface where the colour i s red or reddish-brown free iron i s present as haematite and perhaps limonite, but with depth the blue-grey colour indicates that iron i s present i n the ferrous state. The lack of oxygen i n these layers would keep the iron i n t h i s condition i n d e f i n i t e l y . Since manganese has about the same oxidation-reduction pot e n t i a l as iron, t h i s -59-also would be present i n the subsoils i n the reduced state. (3) Fusion Analyses of Clay Material Less Than .002 mm. i n Diameter For each sample at least 8 gm. of clay were treated as described for removal of free sesquioxides, as t h i s amount was found to be enough for future investiga-t i o n s . After drying on a steam bath i n evaporating dishes i t was ground i n a porcelain mortar to pass through a 150 mesh sieve, and stored i n screw-capped ph i a l s . As a re-sult of the treatment, a l l the clays were reduced to a uni-form l i g h t grey colour except for the surface ones which were of a somewhat darker colour, showing perhaps that the sesquioxides were not a l l completely removed. The clays were fused with anhydrous sodium car-bonate according to Robinson (6), Piper (53) and Vogel (79), and analysed for iron, aluminium, s i l i c a , calcium, magnes-ium and potassium. Exactly 1 gm. of a i r - d r i e d , f i n e l y powdered clay was placed i n a platinum c r u c i b l e , to which approximately 5 gm. of anhydrous C. P. sodium carbonate was added, and mixed thoroughly with the clay to a uniform colour, using -60-th e rounded end of a glass rod. This mixture was covered evenly with 1 gm. of the sodium carbonate, and the crucible placed in a muffle furnace. The temperature was gradually raised to 950° C. and held-there for about half an hour, u n t i l a tranquil melt was obtained. At t h i s point the crucible was taken out and swirled gently and returned to the furnace for another f i v e minutes or so. This enabled any clay p a r t i c l e s that became dislodged on the walls of the crucible to react with the sodium carbonate. The melt was allowed to s o l i d i f y i n the crucible kept on a porcelain plate on the bench, before t r a n s f e r r i n g i t to a large cass-erole, and adding enough d i s t i l l e d water to completely im-merse the c r u c i b l e . This was then covered with a watch glass and l e f t overnight on a steam bath turned to low when the s o l i d i f i e d melt became completely disintegrated. About 25 ml. of concentrated hydrochloric acid was then slowly added to the casserole by means of a pipette, and a f t e r effervescence ceased, the cover glass was washed thoroughly with a minimum of d i s t i l l e d water; the mixture was allowed to react u n t i l a l l the s o l i d p a r t i c l e s were dissolved. The platinum crucible was taken out from the casserole and washed free of s i l i c a using a rubber policeman. -61-On evaporating the solution to dryness i n the casserole, and dehydrating the s i l i c a by heating i n an oven at 110° C. for one hour, the lumps were broken with the flattened end of a glass rod, and 30 ml. of 6 N hydrochloric acid added. The mixture was allowed to digest for about 15 minutes and the s i l i c a f i l t e r e d off on a Whatman No. 42 f i l t e r paper. A quantitative tr a n s f e r r i n g of the s i l i c a from the casserole to the f i l t e r paper was c a r e f u l l y at-tended to and t h i s was washed with d i s t i l l e d water u n t i l free of chloride ions, a l l the washings being collected i n a 600 ml. beaker. The s i l i c a f i l t r a t e was made up to 500 ml. i n a volumetric f l a s k with d i s t i l l e d water and stored. The f i l t e r paper with the s i l i c a was placed i n a platinum crucible and ignited i n a muffle furnace to about 800° C. for half an hour. After allowing the c r u c i -ble to cool i n a desiccator i t was weighed, the s i l i c a moist-ened with d i s t i l l e d water, and 7 to 8 ml. of 48 per cent hydrofluoric acid added, together with 3 to 4 drops of con-centrated sulphuric a c i d . This was slowly evaporated to dryness on a sand bath, a porcelain desiccator plate be-ing used to support the cr u c i b l e . The procedure was re-peated by adding an ad d i t i o n a l m i l l i l i t e r of hydrofluoric -62-a c i d . F i n a l l y , the c r u c i b l e , supported on a stand by a t r i a n g l e , was ignited by a Mekker burner for about 5 min-utes. The s i l i c a was v o l a t a l i z e d as s i l i c i c f l u o r i d e and the loss i n weight calculated as s i l i c i c oxide. To the remaining residue in the crucible was added .5 gm. of potassium bisulphate, and i t was returned to the furnace and fused at 600° C. for 20 minutes. After cooling the melt was dissolved i n water and stored separ-ately, since the s i l i c a f i l t r a t e provided a medium for potassium determinations. The two solutions were analyzed separately for iron, aluminium, titanium, calcium and magnesium, and the res u l t s summed. For analyses the solution was divided into two equal portions, one being used for determination of t o t a l sesquioxides according to the gravimetric method described by Piper (53) • On the f i l t r a t e from t h i s the calcium and magnesium contents were estimated. The other half of the solution was analyzed for the sesquioxides c o l o r i m e t r i c a l l y , thereby providing a check. Potassium was also determined on t h i s portion. Iron and aluminium were determined spectrophoto-met r i c a l l y by the ferron method of Davenport ( 2 5 ) , although -63-other methods such as the thiocyanate method (34) for iron and the Alumimon method for aluminium (60) were also t r i e d , the results obtained showing very good agreement. Calcium and magnesium were estimated by the ver-senate method already described, the procedure for removal of i n t e r f e r i n g t r i v a l e n t cations being excluded because they were preci p i t a t e d before in the t o t a l sesquioxide determination. Potassium was f i r s t determined by the phenyl-tetraboron method (40) but l a t e r the Perkins-Elmer flame spectrophotometer was used (59)» Many determinations of potassium i n known and unknown solutions by the two methods showed agreement to within 5 per cent. The results of these fusion analyses are given i n Table VIII. In Table IX the fusion results have been used to calculate a number of r a t i o s which have been found useful i n interpreting fusion analysis r e s u l t s . It w i l l be noted that Tables VIII and IX also contain r e s u l t s for less than .5 microns clay material from the 18-foot depth from three of the s i t e s . This was included as i t was f e l t that the f i n e r material would be more useful i n i n t e r p r e t -ing the true nature of the clay material. -64-TABLE VIII: SODIUM CARBONATE FUSION ANALYSIS OF CLAY MATERIAL LESS THAN 2 microns DIAMETER (Per Cent of Moisture-Free Clay Material) Depth ( f t . ) I g L o s s ° n S i 0 2 A 1 2 ° 3 F e 2 ° 3 T i 0 2 MgO CaO K 2 0 Murrayville 1 8 12 18 13.40 56.85 21.34 3.85 10.00 57.75 23.96 4.93 12.54 60.05 16.86 3.97 10.21 57.03 24.56 4.51 1.84 0.87 0.17 1.37 1.34 0.96 0.27 1.54 0.67 2.82 0.35 2.27 1.21 3.37 0.59 2.90 Jackman Road . i i -6 10 H i 18 G l a c i a l T i l l Lehman Road 1 3 6 12 18 Haney 7 17 27 37 Clay Material Murrayville 18 Jackman Road 18 Lehman Road 18 29.38 55.02 7.68 4.23 9.95 58.52 23.76 3.82 9.32 54.28 24.35 4.56 10.98 60.04 19.93 3.25 10.20 56.54 21.46 4.51 13.40 56.05 19.87 4.37 22.00 57.70 13.33 2.48 19.07 57.92 13.97 3.81 17.50 56.75 14.45 3.87 16.04 54.85 15.91 4.23 9.50 56.85 19.56 4.85 17.81 61.45 20.28 4.17 10.71 56.26 21.48 5.42 10.22 55.96 20.29 5.96 9.55 55.52 20.81 5.06 Less Than i'5 Microns 21.62 60.58 17.69 6.23 20.60 59.77 18.72 6.13 20.62 62.35 17.83 6.74 1.82 0.28 0.18 0.80 1.25 0.85 0.26 1 .24 1.02 1.30 0.40 2.68 1.34 I . 3 4 0.42 1.85 1.22 2.18 0.66 2.90 1.10 2.50 0.48 1.19 1.40 0.83 0.37 1.52 1.15 0.83 0.23 2.84 1.10 2.40 0.48 3.34 1.48 2.76 0.67 3.88 1.38 3.26 0.96 3.64 1.62 4.30 1.24 2.64 1.35 8.50 1.99 2.75 1.30 8.46 2.04 2.68 1.35 8.55 2.25 2.74 0.36 7.86 0.74 3.42 0.36 7.56 0.87 3.84 0.42 7.36 0.76 3.48 -65-TABLE IX: MOLECULAR RATIOS OF CLAY MATERIAL LESS THAN 2 MICRONS Depth ( f t . ) q . n S i 0 2 S i 0 2 S i 0 2 S i 0 2 SiOj F e 2 0 3 F e 2 0 3 A1 20 3 T i 0 2 *|20g * -> t T i 0 2 CaO MgO Murrayville 1 8 12 18 39.42 4.55 31.91 4.08 40.26 6.09 33.74 3.97 Jackman Road \\ 29.40 6.93 6 24.32 4.25 10 32.,10 3.83 11| 49.54 5.16 18 33.74 4.38 G l a c i a l T i l l 34.76 4.84 41.02 4.07 3.72 57.60 3.61 3.39 119.84 5.35 5.13 63.62 3.56 3.37 46.20 5.41 4.76 65.36 3.64 3.02 71.42 3.32 3.17 60.48 4.62 4.28 64.27 3.87 3.52 66.85 4.01 3.69 Lehman Road 27.40 39.62 17.48 24.54 87.40 33.26 31.45 30.61 42.34 27.65 1 67.12 7.95 59.63 7.15 6.41 62.34 3 40.23 7.02 67.24 5.95 5.48 38.18 6 39.38 6.65 69.12 5.70 5.56 27.61 12 34.46 5.84 49.56 5.02 4.55 - 33.53 18 31.26 4.92 55.36 3.94 3.85 28.42 »y 7 39.24 5.12 46.48 4.54 4.13 45.32 17 30.68 4.41 55.63 3.82 3.56 34.56 27 30.24 4.67 57.44 3.95 3.69 34.62 37 30.62 4.55 55.34 3.94 3.59 33.28 Clay Material Less Than .5 Microns Murrayville 18 26.84 5.88 202.62 4.80 4.72 Jackman Road 18 25.74 5.42 202.62 4.49 4.41 Lehman Road 18 24.76 5.94 200.30 4.79 4.68 13.38 16.45 15.62 - 6 6 -It w i l l be noted from Table VIII that the loss on i g n i t i o n values obtained ranged from 9«55 to 29.38 per cent, and that i n general the values were higher for the surface samples and the less than .5 micron material from the 18-foot depth. In considering the significance of these values i t should be noted that i n the preparation of the material for fusion analyses both the organic matter and free carbonates were removed so that the loss on i g -n i t i o n represents i n the main water of hydration and con-s t i t u t i o n . Therefore, the r e s u l t s suggest a higher con-tent of hydrous or expanding l a t t i c e materials i n the sur-face horizons, and in the less than .5 micron material from the 18-foot depth (48, 62). P a r t i c u l a r significance i s attached to the s i l i c a values reported i n Table VIII which i n a l l cases were over 50 per cent, and i n fact ranged from 54.85 to 62.35 per cent. These high values could indicate the presence of considerable free quartz i n the f i n e material, or the oc-currence of clay and other minerals of high s i l i c a content (42). The titanium content of the clays range from 1.84 to O . 3 6 , and i t i s generally higher for the surface -67-clays, but very low for the less than .5 micron material of the 18-foot depth. Since titanium occurs i n s o i l s p a r t l y as a product of weathering and partly as a component of primary and secondary minerals (50), the re s u l t s might be interpreted by assigning the surface accumulation to greater weathering, and the subsoil values to tp.e primary minerals, present. Attention i s also directed to the magnesium values reported i n Table VIII. It w i l l be noted that the values found ranged from .28 to 8.5 per cent and that i n general the magnesium content of the clay f r a c t i o n increased with depth. The rather high values noted i n the deeper samples i s no doubt related to the nature of the parent rocks which included basalts, grano-diorites, syenites and granites, r i c h in feldspars and ferro-magnesian minerals. During weathering and leaching a considerable portion of the mag-nesium has apparently been removed from the surface layers. Compared to magnesium, calcium was low and did not show as marked change due to weathering. The results for the potassium determinations included i n Table VIII are quite i n t e r e s t i n g and s i g n i f -icant. The values found are i n general quite high for -68-fine clay material, ranging from 0.8 to 3«84 per cent. As for magnesium, the potassium content of the fine f r a c t i o n was higher at depth than i n the surface, and i t i s believed that t h i s also infers a greater degree of weathering i n the surface layer. Table IX includes a number of r a t i o s calculated from the data given i n the previous table, and of the r a t i o s included, p a r t i c u l a r attention i s directed to those for Si02: ^e2^3 t AI2O3 r Ti02, o r ^he s i l i c a sesquioxide r a t i o s and CaO: MgO r a t i o s . Considerable significance i s often attached to silica-sesquioxide r a t i o of s o i l clay material. This i s due to the fact that the d r y s t a l l i n e clay minerals may be divided into two main types, a two-layer type and a three-layer type (41), the former having a silica-sesquioxide r a t i o of about 2, and the l a t t e r , between 3 and 4 (47), and therefore from the silica-sesquioxide r a t i o of the clay material, the type of clay present has sometimes been i n -ferred (47, 50). It w i l l be noted from Table IX that the silica-sesquioxide r a t i o s found ranged from 3.02 to 6.41, and t h i s might be taken as evidence of the presence of the 3-to 1-type clay minerals. However, as was indicated pre-viously, some of the s i l i c a found might occur i n the form - 6 9 -of free quartz or other minerals, and therefore the high silica-sesquioxide r a t i o s cannot be taken as proof of the presence of considerable '2 to 1 l a t t i c e clays. The calcium-magnesium r a t i o s of fine clay mat-e r i a l have been used as an index of the degree of weather-ing; the higher the r a t i o , the more weathered the material (50, 6 2 ) . It w i l l be noted from Table IX that with the surface s o i l s the r a t i o varied widely from 27 to 87, though i n general they were higher than i n the deeper layers, where the values were more constant and i n the order of 30 to 40. S i l i c a - t i t a n i u m r a t i o s also provide some idea of the state of weathering i n the clays, and unlike the calcium-magnesium r a t i o s mentioned above the lower the r a t i o the greater the degree of weathering. According to the results i n Table IX, the r a t i o s range from 41 to 119 i n the less than 2 micron clays, ,with surface values being lowest. With the less than .5 micron clays of the 18-foot depth, however, values range from 200 to 202. • These re-sults might indicate greater weathering on the surface, and a minimum of weathering i n the f i n e r f r a c t i o n s of the deeper layers. From the data i n Tables VIII and IX, apparently chemical weathering has taken place to a much greater extent - 7 0 -on the surface, while i n the deeper layers weathering has not advanced much beyond the physical stage. The d i s t r i b -ution of calcium and magnesium i n the calys suggests leach-ing from the surface s o i l s , but doubtful leaching, and consequently, l i t t l e weathering i n the deeper materials. The results show potassium to increase with depth, reaching i t s highest concentration i n the less than .5 micron clay of the 18-foot depth. This suggests that potash bearing minerals as feldspars and micas occur i n the deeper layers, but that there had been weathering on the surface and the potassium removed by leaching. The content of s i l i c a and the silica-sesquioxide r a t i o i s observed from Tables VIII and IX to be high for clays from both the surface and the deeper layers. In the surface where evidence points to much weathering of primary minerals, these r a t i o s might indicate the presence of 2 to 1 l a t t i c e clays, but i n the case of the deeper layers where the presence of primary minerals has been indicated, the values might be due to the s i l i c a present i n these minerals or to 2 to 1 l a t t i c e clays. (4) Cation Exchange Capacity of the Clay The phenomenon of cation exchange has long been associated with s o i l s and from.the very beginning of s o i l - 7 1 -chemistry i t has been studied in r e l a t i o n to physical con-ditions of s o i l s , s o i l productivity and plant feeding. The actual mechanism of the process has been described at some length (41, 50, 63) and cation exchange capacity i s now recognized as a useful property i n studying the nature of the clay material i n s o i l . In studying the cation exchange capacity of the fine material present i n the stony marine clays, procedures were needed that were e f f i c i e n t and s a t i s f a c t o r y . The actual procedure used for the determination of the ex-change capacity of the fine material was as follows. Exactly one gram of a i r - d r i e d material less than .002 mm. i n diameter was placed in a 50 ml. centrifuge tube, to which 10 ml. of d i s t i l l e d water were added. After completely dispersing the clay by s t i r r i n g with a glass rod, 25 ml. of 2 N ammonium acetate solution were i n t r o -duced and the contents mixed. The mixture was allowed to react for about 24 hours with occasional s t i r r i n g , the glass rod removed, and washed with a minimum of d i s t i l l e d water, and the tube centrifuged at 3,000 r.p.m. for ten minutes. The clay was then washed repeatedly with 95 per cent ethanol u n t i l a l l free ammonium ions were removed, -72-Messler's reagent being used as the in d i c a t o r . About f i v e or six washings were found to be enough. The clay was then quantitatively transferred with d i s t i l l e d water to a Kjeldahl flask and the volume made up to 3 00 ml. Adsorbed ammonia was driven off by steam d i s t i l l a t i o n with sodium hydroxide, and collected i n 10 ml. of .1 N hydro-c h l o r i c a c i d . The unneutralized a c i d i t y was estimated by t i t r a t i o n with .1 N sodium hydroxide from a micro-burette using methyl red as in d i c a t o r . From these values the exchange capacity of the less than .002 mm. material was calculated and appropriate corrections made for i t s a i r -dry moisture content. Because of the small size of sample used, and moreover, the usefulness of thi s determination i n assessing the nature of the clay minerals present, the experiment was conducted i n quadruplicates. The cation exchange capacities of the fin e mat-e r i a l treated for removal of free sesquioxides, as well as those not so treated, are presented below. It w i l l be noted from Table Z that treatment to remove the sesquioxides increased the cation exchange cap-a c i t y found for the fine clay material. This effect i s i n agreement with that found by others (1, 31 52). The increase may be accounted for p a r t l y by the loss i n weight of the -73-TABLE X: CATION EXCHANGE CAPACITY OF THE CLAY MATERIAL WITH AND WITHOUT TREATMENT FOR REMOVAL OF SESQUIOXIDES (Mi l l i - e q u i v a l e n t s per 100 grams) Sample With Without Depth ; Treatment Treatment ( f t . ) Murrayville 1 70 64 8 41 36 12 33 29 18 36 33 Jackman Road l | 73 68 6 38 33 10 33 29 111 35 30 18 35 31 G l a c i a l T i l l 48 42. Lehman Road 1 64 60 3 52 47 6 47 42 12 39 35 18 39 35 Haney 7 75 68 17 42 38 27 39 36 37 41 38 Material Less Than .5 Micron Diameter Murrayville 18 79 77 Jackman Road 18 78 76 Lehman Road 18 77 75 -74-clay material due to removal of the free oxides, and p a r t l y because the thin layer of oxides coating the minerals (63) have been removed by the treatment, thus exposing a layer active surface for the cation-exchange reaction. When considering Table IX, i t should be remem-bered that there i s no single cation exchange capacity value that i s c h a r a c t e r i s t i c of a given group of clay min-erals and that cation-exchange capacity of a given mineral type may vary with many factors so that capacity values may be compared only i f they have been obtained by the same standard procedures on material of comparable t e x t u r a l and s t r u c t u r a l a t t r i b u t e s . Bearing t h i s i n mind, figures are included below for the cation exchange capacities of a number of minerals (41) (47). In comparing these v a l -ues with those i n Table X, i t w i l l be noted that i n both instances the exchange capacities were determined at pH 7. Cation-exchange capacity of clay minerals i n milli-e q u i v a l e n t s per 100 grams: Kaolinite 3 - 15 Halloysite 2 H2O 5 - 10 Halloysite 4 H2O 4 0 - 5 0 Montmorillonite 80 - 150 -75-I l l i t e 10 - 40 Vermiculite 100 - 150 Chlorite 10 - 40 When the cation exchange capacities given in Table X for the fine material are compared with those given above, i t w i l l be noted that i n general they are quite high, ranging from 32 to 80 mi l l i - e q u i v a l e n t s per 100 gm. This suggests that the fin e f r a c t i o n of the stony marine clays must contain some minerals of high base exchange capacity such as montmorillonite, hydrated h a l l o y s i t e , i l l i t e and other minerals.-' Also, the fact that the f i n e material separated from the surface samples had a higher exchange capacity than those from depth, indicates that weathering i n the surface has contributed to the formation of minerals of high exchange capacity. uniform exchange capacities found on the very fine material (less than .5 micron).from the 18-foot samples. The fact that the exchange capacity of the fine f r a c t i o n was 30 to 40 mil l i - e q u i v a l e n t s higher than for the material less than 2 microns, suggests that the coarse clay f r a c t i o n includes much material of doubtful cation exchange capacity, such as quartz or other primary minerals. Attention i s also directed to the very high and - 7 6 -(5) Dehydration of the Clay Material Dehydration involves the loss of any water, adsor-bed, interlayer or l a t t i c e OH- water held by the material. It has been found that the clay minerals lose t h e i r water i n c h a r a c t e r i s t i c ways and t h i s fact has been used as an aid i n t h e i r i d e n t i f i c a t i o n . A number of workers (47* 48, 62) a f t e r studying the property i n d e t a i l have successfully used i t , along with other information to i d e n t i f y the nature of the clay minerals in s o i l s of unknown mineral composition. A number of methods are available for studying dehydration properties, and frequently more than one method i s used. In the present study only one method was used, the simplest, the construction of dehydration curves. The procedure followed involved heating a gram of the fine material i n a platinum crucible u n t i l no f u r -ther loss i n weight occurred. The heating temperature was then raised and the process repeated u n t i l the desired temperature range was covered. The actual temperatures used were 100, 200, 300, 350, 400, 450, 500, 600, 700 and 800° C. The time required for the samples to reach con-stant weight averaged about four hours for temperatures 300° C. to 800° C , but about twelve hours for the 100° C. to 200° C. range. k - 7 7 -Th e weight losses, expressed as per cent of the weight of the sample at 100° C , was plotted against temper-ature and the results appear i n Figures 7, 8, 9 , 10 and 11. In considering the dehydration curves i t should be noted that i n addition to the kind of minerals present other factors might affect the r e s u l t s such as interactions between minerals, the loss of materials other than water, such as COg* and changes i n oxidation of elements as i r o n and manganese. In view of this and the p r o b a b i l i t y that a number of di f f e r e n t clay minerals are found i n the fine f r a c t i o n , interpretation of the dehydration curves i s very d i f f i c u l t and obscure. Assuming, however, that most of the loss i n moist-ure observed was due to the dehydration of the minerals present i n the samples, as i s normally the case, several points of i n t e r e s t r e l a t i v e to the hydration properties of minerals present i n the s o i l i s apparent. On examining the curves i n Figures 7 to 11, i t w i l l be noted that the .002 mm. material from depth l o s t only 10 to 15 per cent moisture, and the loss was almost uniform from 0 to 500° C. At the same time, the re s u l t s show that surface material and the less than .5 micron f r a c t i o n of the 18-foot depths lose much more moisture, the bulk of which was driven off from 200 to 500° C. This observation agrees with the findings of Kelly et a l . (48), that i n the case of highly hydrated clay minerals much -78-of the loss i n moisture occurs within this range of heat-ing. The authors also pointed out that minerals lose l i t -t l e water beyond 500° C , since the collapse of t h e i r struc-ture i s almost complete at thi s temperature. With these results i t i s clear that beyond 500° C. moisture loss was very small. Special attention i s drawn to the curves for the less than .5 material at the 18-foot depths, for not only i s their t o t a l loss i n moisture considered high, but also materials from d i f f e r e n t s i t e s gave almost similar curves. Conparing these values with the appropriate whole clay f r a c t i o n (less than 2 microns diameter), dehydration loss i s much greater for the f i n e r portion, i n d i c a t i n g that i n the coarse clay a large proportion of the minerals are not very hydrated, as i s the case of primary minerals. On studying Figures 7 to 11, the data i n f e r that on the surface and i n the f i n e r fractions (less than .5 micron) from the 18-foot depths, minerals are present with high hydration values such as montmorillonite and hydrous micas. SUMMARY AND CONCLUSIONS Bulk and core samples were collected from sev-era l depths at four s i t e s , Murrayville, Jackman Road, Leh-man Road and Haney, i n the stony marine clays recently -79-described by Armstrong and Brown. The f i r s t three s i t e s were sampled to 18 feet, and Haney to 37 f e e t . At the Murrayville, Jackman and Lehman Road site s the content of clay material less than 2 microns diameter increased with depth, ranging from 4 to 18 per cent near the surface to 20 to 39 per cent at 18 feet. Fine sand and s i l t content decreased with depth. The text-u r a l c l a s s i f i c a t i o n of the material close to the surface ranged from loam to s i l t loam, while the deeper material which more cl o s e l y represented the description of Armstrong and Brown, ranged from loam to clay loam. The material from the Haney site was found to have a higher content of s i l t and clay material. The clay material averaged 46 per cent and the s i l t 42 per cent by weight, and the textural c l a s s i f i c a t i o n was from clay to s i l t y clay. No coarse skeletal material was found i n the Haney samples and a somewhat diff e r e n t mode of orig i n from the other three s i t e s i s indicated. The apparent s p e c i f i c gravity of the material increased with depth, ranging from 1.1 to 1.4 on the surface to 1.4 to 1.8 at 18 feet, indicating greater compaction with depth. True s p e c i f i c gravity also increased with depth, ranging from 2.69 on the surface to 2.74 to 2.82 i n the deeper layers, suggesting a d i f f e r e n t d i s t r i b u t i o n of min-erals with depth. -80-H y d r a u l i c c o n d u c t i v i t y v a r i e d i n v e r s e l y with macro-pores. In the s u r f a c e macro-pores ranged from 1 0 . 6 to 2 0 . 4 per cent by volume, with h y d r a u l i c c o n d u c t i v i t y being between 0 . 2 to 1 . 2 inches per hour. At depth macro-pores ranged from 2 . 4 to 4 . 5 per cent, with c o n d u c t i v i t y values too s m a l l to be determined a c c u r a t e l y . T o t a l por-o s i t y g e n e r a l l y decreased with depth, values on the sur-face being between 4 7 to 6 0 per cent, and i n the deeper l a y e r s between 3 4 to 4 1 per cent. The s o i l volume occupied by a i r decreased with depth to very low v a l u e s , and anaero-b i c c o n d i t i o n s e v i d e n t l y p e r s i s t . Chemical analyses r e v e a l e d the presence of much fr e e lime i n the s u b s o i l s ; a l s o , c o n s i d e r a b l e exchangeable sodium was found i n the deep samples and t h i s may be taken as evidence s u p p o r t i n g the c o n c l u s i o n t h a t the m a t e r i a l i s of marine o r i g i n . The s u r f a c e s o i l from each s i t e was a c i d i n r e -a c t i o n , pH's ranging from 5 . 0 to 5 « 8 , and the exchange mat-e r i a l was o n l y from 4 2 to 7 9 per cent base s a t u r a t e d . How-ever, the s o i l at depth was a l k a l i n e i n r e a c t i o n with pH 7 . 4 to 9 . 4 , and i t was completely s a t u r a t e d with the c a t i o n s calcium, magnesium, sodium and potassium. These r e s u l t s i n -d i c a t e t h a t l e a c h i n g has been much more a c t i v e c l o s e to the s u r f a c e . When the m a t e r i a l l e s s than 2 microns i n diameter was separated from the s o i l c l o s e to the s u r f a c e i t had a -81-high c a t i o n exchange c a p a c i t y of from 64 to 74 m i l l i -e quivalents per 100 gm. The same s i z e f r a c t i o n from depth had c a t i o n exchange c a p a c i t i e s ranging from 33 to 47, and the l e s s than . 5 micron f r a c t i o n from 18 f e e t , c a t i o n ex-change c a p a c i t i e s of from 77 to 79 m i l l i - e q u i v a l e n t s per 100 gm. The f i n e c l a y f r a c t i o n was a l s o found to be high i n s i l i c a , have a high s i l i c a - s e s q u i o x i d e r a t i o , and give up considerable amounts of water on heating. These r e -s u l t s i n d i c a t e that the f i n e f r a c t i o n i n c l u d e s a consider-able amount of r e a c t i v e m a t e r i a l with exchange p r o p e r t i e s , such as m o n t m o r i l l o n i t e , hydrous mica, i l l i t e or r e l a t e d minerals. 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