Hydrogen-isotope geochemistry of diagenetic clay minerals from Cretaceous sandstones, Alberta,...

Applied Geochemistry, Vol. 5. pp. 657~b68, 1990 0883-2927/90 $3.00 + .00 Printed in Great Britain Pergamon Press pie

Hydrogen-isotope geochemistry of diagenetic clay minerals from Cretaceous sandstones, Alberta, Canada: evidence for exchange

FRED J. LONGSTAFFE and AVNER AVALON* Department of Geology, University of Western Ontario, London, Ontario N6A 5B7, Canada

(Received 4 December 1989; accepted in revised form 26 April 1990)

Abstract--The 6D and 6180 values of diagenetic kaolinite and 10/k clay minerals (illite, illite/smectite) have been determined for Lower Cretaceous Viking Formation marine sandstones and conglomerates, Upper Cretaceous basal Belly River Group shoreline and deltaic sandstones, and overlying Belly River/Brazeau Groups continental sandstones from the western Canada sedimentary basin. Early and late diagenetic kaolinites have a remarkably small range of 6D values (-132 to -112%o, Viking Formation; -137 to -128%o, Belly River/Brazeau Groups) relative to their 6180 compositions (+ 13.8 to +26.9%0, Viking Formation; +5.9 to + 12.7%o, Belly River/Brazeau Groups). The 6D values are also much lower than commonly reported for kaolinite.

Calculations indicate that the diagenetic kaolinite from all units is in, or close to, hydrogen-isotopic equilibrium with present formation waters at present subsurface temperatures. Within the limits of available fractionation data, similar observations can be made for diagenetic 10 ,~ clay minerals from these units (6D = -132 to -107%o, Viking Formation; -138 to -123%o, Belly River/Brazeau Groups). By comparison, a general state of oxygen-isotope equilibrium does not exist between diagenetic kaolinite and present formation waters. Kaolinite has retained oxygen-isotope compositions characteristic of neoformation during earlier stages of diagenesis. Some diagenetic 10 A clay minerals (e.g. Belly River/Brazeau Groups) may be in oxygen-isotope equilibrium with present formation waters because of neoformation from these waters (in sandstones), or oxygen-isotopic exchange during the smectite to illite transform- ation (in shales).

The results of this study suggest that hydrogen-isotope re-equilibration between diagenetic kaolinite and formation water in sandstones can occur independent of oxygen-isotope exchange at temperatures as low as ~40°C. Interpretation of hydrogen- and oxygen-isotope compositions for clay minerals from such systems (i.e. high water/rock ratio, low temperatures) should therefore be decoupled.

INTRODUCTION

THE PURPOSE of this paper is to demonstrate that diagenetic kaolinites from Cretaceous sandstones in the western Canada sedimentary basin have acquired their hydrogen-isotope compositions by isotopic equilibration with existing formation waters. In con- trast, oxygen-isotope compositions have been retained by the kaolinite which are characteristic of the porewaters responsible for clay crystallization within the pore system. Evidence for hydrogen- isotope re-equilibration between diagenetic 10 A, clay minerals (illite, illite/smectite) and formation waters is also presented.

The 61SO values of diagenetic minerals such as quartz and clay minerals are commonly used to deduce the oxygen-isotope compositions of ancient porewaters (LAND and DurroN, 1978; LONGSTAFFE, 1984, 1986; LONGSTAFFE and AVALON, 1987; AVALON and LONGSTAFFE, 1988). Diagenetic minerals in sandstones generally are not in oxygen isotopic equilibrium with each other, but instead retain compositions determined by the conditions which prevailed during their initial crystallization. In this paper, we address

*Present address: Geological Survey of Israel, 30 Mal- chei Israel Street, Jerusalem 95501, Israel.

whether a similar situation exists for hydrogen isotopes.

Temperature, grain-size, surface area and crystal chemistry are the important factors controlling isotopic exchange between minerals and water. Given the very low rates of solid-state diffusion at sedimentary temperatures, it is generally presumed that isotopic exchange between minerals and water requires dissolution and recrystallization (O'NEIL, 1987; LONG- STAFFE, 1983, 1987, 1989). Oxygen isotopic exchange between quartz and water, for example, is insignificant at sedimentary and diagenetic temperatures. Oxygen isotopic exchange involving clay minerals is more complicated. Oxygen (and hydrogen) from loosely bound interlayer water in smectites equilibrate with external water vapour at room temperature within hours or days (SAVIN and EPSTEIN, 1970a), whereas exchange of oxygen isotopes between water and structural sites in clay minerals is very slow at low temperatures (<100°C; O'NEIL and KHARAKA, 1976; JAMES and BAKER, 1976). Results for natural systems confirm the experimental observations. In the absence of clay neoformation, oxygen-isotope exchange between oceanic clays and sea water at <5°C is insignificant over hundreds of thousands'of years, even for very fine (<0.3 to <0.1/~m) smectitic material (SAVtN and EPSTEIN, 1970a,b; YEn and

657

658 F.J. Longstaffe and A. Ayalon

SAVIN, 1976; ESLINGER and YEn, 1981; YEH and ESLINGER, 1986).

The rate of oxygen-isotope exchange between clay minerals and water increases as temperatures rise, with significant exchange occurring by 300°C; this exchange results from solution and redeposition of the clay mineral (O'NEIL and KHARAKA, 1976). Smec- tite is generally more rapidly affected than kaolinite or illite (O'NEIL and KHARAKA, 1976). Exchange is facilitated by mineralogical reactions, such as the smectite to illite conversion (YEn and SAVIN, 1977; WHITNEY and NORTHROP, 1988).

While hydrogen-isotope exchange also occurs very slowly at low temperatures, experimental data suggest that the rate is more rapid than for oxygen (O'NEIL and KHARAKA, 1976). Significant exchange can occur at temperatures <100°C, smectitic clays being most readily affected. At temperatures as high as 200°C, extensive hydrogen-isotope exchange can be unaccompanied by major changes in chemical or oxygen-isotopic composition. This behaviour suggests that replacement of H + rather than (OH)- controls hydrogen-isotope exchange between clay minerals and water at and below this temperature (O'NEIL and KHARAKA, 1976; Kharaka and CAR- OTHERS, 1986; SAXaN and LEE, 1988; KYSER, 1987). At higher temperatures, replacement of (OH)- should become much more important in controlling hydrogen- (and oxygen-) isotope exchange with water.

Regardless of the experimental observations, evidence concerning the extent of hydrogen-isotope exchange between clay minerals and water is contra- dictory for natural systems. YEH and EPSTEIN (1978) reported that hydrogen-isotope exchange between sea water and 2-3 Ma old detrital oceanic clay minerals (mostly smectite and illite) was confined to the <0.1/zm fraction (which could also contain neD- formed clay). Similar results have been reported for Pleistocene samples from the Aleutian Trench (EsL- INGER and YEH, 1981). Other studies, however, suggest that post-crystallization hydrogen-isotope exchange does occur: (i) the expandable clay mineral halloysite rapidly exchanges hydrogen-isotopes with groundwater at surface temperatures (LAWRENCE and TAYLOR, 1972); (ii) significant post-formational hydrogen-isotope exchange has affected Permian kaolinites at temperatures not exceeding ~80°C (BIRD and CHIVAS, 1988); (iii) retrograde H-isotope alteration of clay minerals by meteoric water has been described by WILSON et al. (1987) from Middle Proterozoic unconformity-type U deposits; and (iv) diagenetic dickites from Cretaceous rocks of the Alberta Deep Basin may have exchanged hydrogen- isotopes with existing formation waters (TILLEY and LONGSTAEEE, 1989).

Complete hydrogen-isotope equilibration between illite/smectite (<0.2~tm) and shale porewaters can also occur during burial diagenesis of argillaceous rocks. For example, in the Texas Gulf Coast, a depth-

dependent increase in illite/smectite 6D values is accompanied by a decrease in the hydrogen-isotope composition of formation waters as temperatures rise to ~ 170°C, and this behaviour can be predicted using a simple closed system material-balance calculation (KHARAKA and CAROTHERS, 1986; YEH, 1980; see also LUNDEGARD, 1989). In this shale-dominated system, however, a mineralogical reaction (smectite to illite conversion) is critical in facilitating extensive hydrogen- (and oxygen-) isotopic exchange (YEH and SAVIN, 1977; YEH, 1980).

GEOLOGICAL BACKGROUND

Geological setting

Sandstones and conglomerates have been sampled from the Lower Cretaceous Viking Formation, and the Upper Cretaceous Belly River and Brazeau Groups of the western Canada sedimentary basin (Fig. 1). During the earlier part of late Albian time, the interior of western North America was inundated by transgressive seas from the north and, to a lesser extent, from the south (WILLIAMS and STELCK, 1975; WEIMER, 1983), resulting in the deposition of marine shales (Joli Fou Formation). A regression toward the end of late Albian time marked the beginning of deposition of the Viking Formation, the sediment being derived largely from the rising Cordillera to the west. The Viking Formation consists of a coarsening upward succession of interbedded fine-grained sandstone and shale, fine- or medium-grained sandstone, and chert-pebble conglomerate and pebbly sandstone of dominantly marine origin. HEIN et al. (1986) have suggested that deposition of the Viking Forma- tion occurred during progradation of a shoreline- attached, clastic wedge during a regression. Cut-and- fill of channels dissected the clastic wedge, and marine reworking subsequently transformed some of the

B . C . " ""-'--. ~. H U D S O N

( Z" Is, s,<. i 'c....

L 5 0 0 K M j " "'q" ~ " ~ " ~ . ~

Fro. 1. Location of study areas (Belly River/Brazeau Groups, including the basal Belly River sandstone, stippled area; Viking Formation, dark area), Details of outcrop and well locations are given in LONGSTAFFE and AYALON (1987)

and AYALON and LONGSTAFFE (1988).

H isotopes in Cretaceous diagenetic clays, Alberta Basin 659

sediment into sheet-like deposits of sands and pebble beds on the offshore shelf. During the later early Turonian, a second major transgression occurred, ending Viking Formation deposition. Muds of the overlying Colorado Group were deposited at this time.

The Upper Cretaceous Belly River and Brazeau Groups are part of an eastward-thinning clastic wedge associated with the retreat of the Lea Park sea during Campanian time (WILLIAMS and BURgE, 1964). While most of the Belly River and Brazeau Groups were deposited in a non-marine setting, the lowermost portion, the basal Belly River sandstone, is a progradational complex of nearshore, shoreline and deltaic sands that grade upward into fluvial deposits (IwuAGWU and LERBEKMO, 1982, 1984; SHOULDXCE, 1979). In south-western Alberta, the Belly River Group consists mainly of mudstones interbedded with lenticular, fine-to medium-grained sandstones. These rocks are conformable with the underlying marine shales of the Wapiabi or Lea Park Formations, and the overlying marine shales of the Bearpaw Formation. The Bearpaw Formation thins northward; its eventual disappearance renders the Belly River and Edmonton Groups inseparable. The resulting continental succession is referred to as the Brazeau Group (RAHMANI and LERBEKMO, 1975; IWUAGWU and LERaEKMO, 1982, 1984).

The first phase of the Laramide Orogeny began in the Late Cretaceous, causing thrusting and uplift along the eastern Cordillera (TAYLOR et al., 1964; DXCgINSON and SNYOER, 1978). To the east, continental deposition dominated throughout the Late Creta- ceous and into the Early Tertiary as the sediment was shed from the Cordillera into the downwarped basin (BEAUMONT, 1984). Maximum burial of the Viking, Belly River and Brazeau stratigraphic units probably occurred in the late Paleocene or early Eocene (TAY- LOR et al., 1964; HITCHON, 1984). At this time the major pulse of the Laramide Orogeny (early Eocene) resulted in extensive deformation (overthrusting) in the eastern Cordillera and significant uplift of the sedimentary basin in Alberta. The uplift in western Alberta created a very high potentiometric surface, causing large-scale, regional recharge of meteoric water into the rocks of the study area (HITCHON, 1984). Extensive erosion of the accumulated Tertiary and Upper Cretaceous rocks ensued (TAYLOR et al., 1964; BEAUMONT, 1981).

Diagenesis and oxygen-isotope evolution of porewaters

The oxygen-isotope geochemistry, diagenesis and pore water evolution of the Viking Formation have been described in detail by LONGSTAFFE and AVALON (1987), from which the following summary has been prepared. Early, shallow diagenesis involving formation of kaolinite, calcite and chlorite began in the

presence of pore waters with 6SSo values ~-1%0 at low temperatures (Fig. 2, Stage 1). The early diagenetic kaolinite, in particular, has an average 6180 value of ~- +26.5 + 2%0, and formed at temperatures of ~-10 ° to 30°C (see Fig. 5a of LONGSTAFFE and AVALON, 1987). This kaolinite is commonly engulfed by quartz overgrowths (Figs 3a,b).

As burial diagenesis proceeded, diagenetic chlorite, quartz overgrowths and dolomite crystallized, and coexisting pore waters became enriched in 180 (Fig. 2, Stage II). Burial diagenesis ended with basin uplift. Influx of low-180 meteoric water at this time stimulated feldspar dissolution (mostly plagioclase), albitization, and the initiation of crystallization of kaolinite, calcite and ankerite (Fig. 2, Stages III and IV). Kaolinite is particularly abundant as a late diagenetic pore-filling cement in coarse-grained sandstones (Fig. 3c); it has much lower 6180 values (~+14 _+ 3%0) than the earlier generation of kaolinite. During late kaolinite crystallization, pore waters declined in temperature from about 120 ° to 60°C, following a pathway toward the present range of temperatures and pore water 6180 values in the Viking Formation (Fig. 2, Stages IV and V). The cooling implied by this trajectory is a predictable consequence of post-Laramide erosion. The final major stage of diagenetic mineralization is rep- resented by 10,~ clay minerals (6180~+14 ___ 2%0; illite, <10% expandable layers; illite/smectite, 20- 35% expandable layers). They occur as webby to mat-like aggregations, and as filamentous material within pore space (Fig. 3d), coating most other diagenetic phases, including kaolinite.

The oxygen-isotope geochemistry, diagenesis and pore water evolution of the basal Belly River sandstone have been discussed by LONGSTAFFE (1986) and

i o

O

0 20 40 I10 O0 100 l~tO 140

Temperature ° C

FiG. 2. Interpretive porewater evolution path (stippled area) for the Viking Formation sandstones and conglomerates (from LON6STAFFE and AVALON, 1987). The curve has been deduced from the paragenetic sequence and the oxygen-isotope compositions of the diagenetic minerals (see LOr~GSTAFFE and AVALON, 1987, for details on the construction of this curve). Stage I: early (shallow) diagenesis; Stage I1: burial diagenesis; Stage III: period of maximum burial and uplift/topographic high (major influx of meteoric water begins); Stage IV: continued influx of meteoric water during erosion and cooling; Stage V: present

subsurface conditions.

66{) F.J. Longstaffe and A. Ayalon

Fro. 3. (a, b) Early diagenetic kaolinite (K) engulfed by authigenic quartz (AQ), Viking Formation; kaolinite B in Fig. 2 (from LONGSTAFFE and AYALON, 1987); (C) late diagenetic kaolinite (K) filling l?ores; Viking Formation; kaolinite A in Fig. 2 (from LONGS'rAFFE and AVALON, 1987); (d) diagenetic 10 A clay minerals (I) coating carbonate cement (Cc), Viking Formation (from LONGSTAFFE and AYALON, 1987); (e) pore-filling kaolinite, basal Belly River sandstone, Belly River Group (from AYAI.ON and LONGSIAFFE, 1988); (f) vermiform kaolinite, basal Belly River sandstone, Belly River Group (from AYALON and

LONGSTAFFE, I988).

AYALON and LONGSTAFFE (1988), from which the following summary has been prepared. Similar diagenetic patterns are also present in the overlying continental sandstones of the Belly River/Brazeau Groups (AYALON and LONGSTAFFE, in prep.). Early, shallow diagenesls began in the presence of brackish or fresh water, which became enriched in lSo during burial

(Fig. 4, Stages I and II). Recharge by meteoric water following uplift led initially to feldspar dissolution and crystallization of diagenetic quartz (Fig. 4, Stage III). Influx of meteoric water continued during erosion, accompanied by the crystallization of kaolinite (Fig. 4, Stage IV; 110°-60°C), then illite, illite/smec- tire (Fig. 4, Stage V) as the pore water evolved


toward present temperatures and 61So values. Pore- filling diagenetic kaolinite (6180~+10 _+ 2%o) is generally the most abundant clay cement in these rocks, occurring as booklets of pseudohexagonal flakes (Fig. 3e) or vermiform stacks (Fig. 3 0. Diage- netic illite (<5% expandable layers) and illite/smectite (~25% expandable layers; 6 Is O ~ +11.5 _+ 2%o) have a similar morphology to equivalent material from the Viking Formation.

ANALYTICAL METHODS

The oxygen- and hydrogen-isotope data are reported in the normal 6-notation relative to Vienna Standard Mean Water (V-SMOW) (after CRAm, 1961a). Oxygen was extracted from the clay minerals using the BrF 5 method of CLAY'ION and MAYEDA (1963) and quantitatively converted to CO 2 over red-hot graphite. Replicate analyses of un- knowns were normally better than _+ 0.2%0. NBS-28 gave an average value of +9.62 _+ 0.12%o, using an oxygen-isotope CO2-H20 fractionation factor of 1.0412 at 25°C to calibrate the reference CO 2 gas. The hydrogen-isotope measure- ments were conducted at the University of Saskatchewan using the uranium technique described by BIGELEISEN et al. (1952), as modified by KYSER and O'NEIL (1984). A 6D value of -65%0 for NBS-30 (biotite) and reproducibility of _+3%0 (2a) for clay mixtures is reported by the Saskatchewan laboratory (WILSON et al., 1987) for this procedure.

Several kaolinite size-fractions (<2/~m, 2-5#m, 2- 10/~m) were analyzed for their dD values, depending on purity and kaolinite abundance. No systematic variations in dD values were observed among the size-fractions. The 10/~ clay minerals were isolated in the <0.2/~m size- fraction, which contains virtually pure authigenic clay. Chemical treatments were avoided in preparation of the samples for hydrogen-isotope analysis, and no corrections were applied to the bD values for contamination by other phases (essentially quartz). Mineral separation procedures used to prepare kaolinite and 10/~ clay minerals for oxygen- isotope analysis have been reported in LONGSTAFFE and AYALON (1987) and AYALON and LONGSTAFFE (t988), as are

i i i i i i i i i 1 i i

0

/ . - ' " . - o ~ 1 , '11

4 / ..~.~-'~../ I I / /j~//~/~.. -;. ¢11~-~ -" ""

0 /- ~" m ~/. Belly River

-lo v >" Summary I I I I I I I I I I I I

0 20 40 80 I10 100 120

T e m p e r a t u r e o C

FIG. 4. Interpretive porewater evolution path for the basal Belly River sandstone, Belly River Group (from AVALON and LONGSTAFFE, 1988). The curve has been deduced from the paragenetic sequence and the oxygen-isotope compositions of the diagenetic minerals (see AVALON and LONG- STAFFE, 1988, for details). Diagenetic stages as in Fig. 2. Dashed arrows indicate approximate ranges for the crystal-

lization of specific diagenetic minerals.

the procedures used to correct for contamination in kaolinite samples.

RESULTS AND DISCUSSION

K a o K n i ~

Very low 6D values ( - 132 to - 112%o; Table 1, Fig. 5) were obtained for diagenetic kaolinite from the Viking Formation sandstones and conglomerates. The spread in 6D values (20%o) is small, and the same range was obtained for both early and late gener- ations. A proportionally much larger range in oxygen-isotope compositions (+13.8 to +26.9%o; Table 1, Fig. 5) is present, early diagenetic kaolinite having much higher 6180 values (+25.4 to +26.9%0) than the later generation (+ 13.8 to + 16.7%o). Addi- tional early diagenetic kaolinite samples from the Viking Formation with 6180 values as high as +28.2%0 are reported in LONGSTAFFE and AYALON (1987).

Even lower and more tightly clustered 6D values ( -137 to -128%o) were obtained for kaolinite from the Belly River/Brazeau Groups, including the basal Belly River sandstone. Like the Viking Formation samples, these kaolinites exhibit a proportionally much larger range in 6180 values (+5.9 to +12.7%o) than 6D values. That kaolinite samples from the basal Belly River sandstone exhibit a narrower range in 6180 values relative to the other units studied is an artifact of subsample selection; diagenetic kaolinite from the basal Belly River sandstone ranges in 5180 values from +7.8 to +11.9%o (AYALON and LONG- STAFFE, 1988).

The 6D values reported here are significantly lower than commonly reported for kaolinite. Hydrogen-isotope compositions of clay minerals in sedimentary rocks normally range from about - 8 0 to --25%o (SAVIN and EPSTEIN, 1970a; LAWRENCE and TAYLOR, 1971, 1972; HASSANIPAK and ESLINGER, 1985). Lower diD values, however, do occur, including - 107 to -94%0 for Permian kaolinites of weathering origin (BIRD and CHIVAS, 1988), and -131 to -93%0 for late diagenetic dickite from Cretaceous sandstones in the Alberta Deep Basin (TILLEY and LONGSTAFFE, 1989).

The possibility of post-crystallization hydrogen- isotope exchange between diagenetic kaolinite and formation waters can be evaluated by a comparison of measured and calculated pore water compositions. Available data (HITCHON and FRIEDMAN, 1969; CON- NOLLY et a l . , 1990) for the diD values and temperatures of formation waters from the Belly River Group and Viking Formation in the study area are shown in Fig. 6a. Curves describing the maximum and minimum hydrogen-isotope compositions of pore water that would be in equilibrium with kaolinites from the Belly River/Brazeau Groups (including the basal Belly River sandstone) and Viking Formation are

662 F.J . Longstaffe and A. Ayalon

also shown, calculated using the hydrogen-isotope geo the rmomete r of LAMBERX and EPSTEI~ (1980). This geo the rmomete r was calibrated using naturally occurring samples, and is generally consistent with results f rom experimental studies (SuzvoKI and EPSTEIt~, 1976; LIU and EPSTEIN, 1984).

The 6D values of format ion waters from the Belly River Group ( - 1 2 1 to -99%0; average = -107%o) are shown in Fig. 6a to be very similar to those calculated ( - 1 1 0 + 3%0) using the average 6D value of kaolinite from the Belly River /Brazeau Groups, assuming equil ibration at the average subsurface temperature (41 + 10°C). The 6D values of Viking Format ion pore water ( - 1 0 9 to -83%o) also tightly bracket the composit ions calculated from the 6D values of Viking Format ion kaolinite (Fig. 6a). The average bD value of formation water obtained for the Viking Format ion assuming equil ibration at the average current formation water temperature ( - 9 9 + 3%0; 42 _+ 10°C) is very similar to the actual formation water composi t ion (average = -94%0). These com- parisons suggest that diagenetic kaolinite from all units studied is in hydrogen-isotopic equil ibrium with existing formation waters at present subsurface temperatures, or that current conditions are not much different from those at the t ime of kaolinite precipitation, both early and late.

The former explanation best fits our data. Original bD values of the early diagenetic Viking Format ion kaolinite, which probably formed at temperatures of

20 _+ 10°C from waters with a 6180 value of - 1 + 1%0 (Fig. 2), would have b e e n ~ - 3 0 + 10%o, not

- 123%o, assuming that the hydrogen-isotopic composition of pore waters during this very early, shallow stage of diagenesis can be est imated from the meteor ic water line (CRAI6, 1961b). Similar 6D values would result if sea water was important during very shallow diagenesis (e.g. see SAVIN and YEH, 1981). It is more difficult to predict the original 6D values of the later generat ion of kaolinite, but their higher temperatures of formation (60 ° to 120°C) from pore waters somewhat enriched in 180 relative to present formation waters (Figs 2 and 4) suggest that at least a 20%0 deplet ion in deuter ium has occurred since initial crystallization.

Calculated and measured 6280 values for Belly River /Brazeau Groups (including the basal Belly River sandstone) and Viking Format ion pore waters are compared in Fig. 6b. The actual 61So values of formation water overlap only a small port ion of the range required for all kaolinite samples to be in isotopic equil ibrium with existing formation waters at present subsurface temperatures .

This dichotomy between the behaviour of hydrogen and oxygen isotopes is summarized in Fig. 7. To

18 construct this diagram, 6 O and 6D values of formation water have been calculated for each kaolinite sample assuming complete isotopic equil ibrium at the present subsurface temperature for that location. Calculated and measured hydrogen-isotope compo-

Table 1. Stable isotope results for kaolinite from the Viking Formation, and Belly River and Brazeau Groups

Depth Diagenetic 6D%o 6 t80%o Sample location (m) Rock type stage SMOW SMOW

Viking Formation 4-3-4244 W5* 13-19-40-6 W5 14-9-39-2 W5 10-24-35-7 W5 10-9-41-3 W5 11-23-31-24 W4 11-23-31-24 W4

(Basal) Belly River sandstone, 4-20-43-2 W5 2-32-46-3 W5 8-11-46-7 W5 4-21-47-15 W5 10-28-48-1 W5 Red Deer River

1909.6 Fine-grained sandstone Early - 113 26.9 2257.8 Conglomerate Early - 132 25.4 1904.5 Coarse-grained sandstone Late -123 13.8 2734.6 Conglomerate Early + Late _ 112 18.3 1 9 2 3 . 3 Conglomerate Late - 131 14.2 1367.8 Conglomerate Late - 130 15.7 1373 .4 Fine-grained sandstone Late - 116 16.7

Belly River Group 1108.6 Medium-grained sandstone Late - 131 9.6 1079.0 Medium-grained sandstone Late - 131 8.7 1269.9 Medium-grained sandstone Late -135 8.6 2099.8 Medium-grained sandstone Late - 134 9.2 796.4 Medium-grained sandstone Late - 133 9. I

outcrop Medium-grained sandstone Late - 134 9.9

Belly River/ Brazeau Gr6.ups (continental sequence) 6-29-41-27 W4 975.4 6-29-41-27 W4 986.9 4-35-41-5 W5 1345.7 6-19-46-5 W5 1056.1 12-21-47-15 W5 2019.6 Red Deer River outcrop Crowsnest River outcrop Little Red Deer River outcrop

Silty fine-grained sandstone ? -128 Very fine-grained sandstone Late - 133

Fine-grained sandstone Late - 132 Medium-grained sandstone Late - 133 Medium-grained sandstone Late - 130 Medium-grained sandstone Late - 137

Fine-grained sandstone Late - 131 Medium-grained sandstone Late - 134

nd 12.6 11.3 7.4 6.0 5.9 6.2 12.7

nd = Not determined. * Well location according to Province of Alberta grid system by legal subdivision (LSD), section, township,

meridian. range and


.40

0

120

-loo o t ~ -200

-240 0

early kaolinite late iwolinite ~1~

• • •

~ x ~ x l m m •

Kmollnite

5 10 15 20 25 30 15 6 0 kaolinite, (SMOW) permill

FIG. 5. Oxygen and hydrogen isotope results for diagenetic kaolinite.

I s Viking

+ basal Belly River

x Belly River/Brazeau

(a)

(b)

M

Im

.2

-20 ! . ~ Viking water

-6o

*" ~ ~ r ~ , - ~ . ~ . . . _ dk ~ kaolinite ]

~O Brazeau kaolinite

120 I 0_. ~ .... : . _ _ ~ ~ 132 pcrmill, Viking kaolinite

~ -140 ~ - 1 3 7 !~n'nill, Belly River/ Brazeau kaolinite

-loo 0 20 4o 6o 8o lOO 120 140

Temperature (°C)

4 ~ " 6 +13.8 I~rrnill, Viking 2 .9 pcrmill, Viking ~ kaolinite

~ - kaolinite 0 +12.7 pcrmill, Belly River/

. Brazeau kaolinite t l

~2 g Viking water / /

-6 +5,9 pcrmill, Belly River/ Brazeau kaolinite

-8

-10

-12

-14 // Be)ly River water

-16 / / ' " ' / ' t , I , I , I , 0 20 40 60 80 100 120 140

Temperature (°C) FIG. 6. Comparison of calculated and measured 6D (Fig. 6a) and 6180 (Fig. 6b) values for formation waters from the Viking Formation and Belly River/Brazeau Groups, including the basal Belly River sandstone: data for diagenetic kaolinite. The temperatures and compositions of formation water samples are from HIXCHON and FRIEDMAN (1969) and CONNOLLV et al. (1990): + = Belly River Group formation waters; • = Viking Formation formation waters. The calculated curves for the formation water compositions were obtained using the hydrogen-isotope kaolinite-water equation of LAMBERT and EPSTEIn (1980), the oxygen-isotope kaolinite-water equation of LAND and DuYroN (1978), and the maximum and minimum 6D and 6180 values, respectively, for kaolinite from each unit (heavy lines, Viking Formation:

light lines, Belly River/Brazeau Groups).


40 / mcleoric

.---- 20 water line

-20 Standard Meaa Ocean Whter

-40 Formation • Calculated Viking water water, Viking i + Calculated basal Belly River water

O -60 Formation water, / ! i x Calculated Belly River/Brazeau water

~) I BellyRiver / ~f ~ -100 ~ .'120140 -80 h~) ~ "~Y~/~- m m ~~ water surface I... [ •

- 1 6 0 " " " ] I . . . . I . . . . I . . . . I . . . . I . . . . I . . . . I '

-25 -20 -15 -10 -5 0 5 10 15 15

6 O of formation water, permill

FiG. 7. Comparison of calculated and measured oxygen- and hydrogen-isotope compositions for formation waters from the Viking Formation and Belly River/Brazeau Groups, including the basal Belly River sandstone: results for diagenetic kaolinite. Boxes outline the range of measured compositions for formation waters from the Viking Formation and Belly River Group, and local surface water in the study areas (from HITCHON and F R I E D M A N , 1969 and CONNOLLY et al., 1990). Individual data points are formation water compositions calculated assuming complete oxygen and hydrogen isotopic equilibrium between each diagenetic kaolinite sample and formation water at the present subsurface temperature of

that locality. Calculations have been performed using the isotopic geothermometers listed in Fig. 6.

sitions for the formation waters are in close agreement. The match for the oxygen-isotope data is much worse; most kaolinite samples are not in oxygen isotopic equilibrium with existing formation waters at present subsurface temperatures.

Four outcrop samples have been excluded from this analysis; subaerial exposure effectively termi- nated saturation with formation waters at some temperatures (<40°C) which cannot be measured directly. The isotopic composition of kaolinite from these outcrop samples is nevertheless indistinguish- able from that of subcrop samples, and probably experienced similar water-rock interaction until very recent times. Neither hydrogen- nor oxygen-isotope equilibrium has been established between diagenetic kaolinite and local meteoric water (6D-~- 158 +_ 8%o; 61So~-19 + 1Too; HITCHON and FRIEDMAN, 1969) at the outcrop localities.

10 A Clay minerals

Like kaolinite, late diagenetic 10 ,~, clay minerals (illite and illite/smectite) from these rocks have very low 6D values ( -132 to -107%o, Viking Formation; -138 to -123%o, Belly River/Brazeau Groups, including the basal Belly River sandstone; Fig. 8, Table 2). These data qualitatively suggest that hydrogen- isotope exchange with present formation waters has occurred. The extent of such exchange, however, is difficult to assess quantitatively because the H- isotope fractionations for illite and illite/smectite are very poorly known, especially at low temperatures (SAVIN and LEE, 1988). The equation of YEH (1980) has been used to calculate the range of 6D values for formation waters in equilibrium with the 10,~ clay minerals (Fig. 9a). Calculated and measured bD values compare reasonably well at temperatures typi-

o

0 -80 -120

I

.~ .16o

~ -200

-240 0

x t , ~ + + + ~ •

. . . . i . . . . | i i M i I . . . . i . . . . a . . . .

5 10 15 20 25 6 IS 0 10)~ clays, (SMOW) permil l

10~ Clay Minerals

• Viking + basal Belly River x Belly River/Brazcau

30

FIG. 8. Oxygen and hydrogen isotope results for diagenetic 10 ,~ clay minerals.


cal for formation waters from both the Belly River Group and the Viking Formation. The ~10 permill offset between calculated and measured 6D values probably results as much from the poor state of knowledge of fractionation in this system as anything else.

A similar comparison for oxygen-isotopes is given in Fig. 9b, using the illite/smectite-water equation of SAVIN and LEE (1988). The 6180 values of Belly River Group formation waters bracket very closely the calculated range of compositions. Agreement between measured and calculated water compositions is less satisfactory for the Viking Formation.

Calculated isotopic compositions of pore water in equilibrium with specific 10/~ clay minerals at present subsurface temperatures are compared with the actual isotopic data for the formation waters in Fig. 10. Two outcrop samples have been excluded for reasons discussed earlier. Shale laminations within the sandstones will be discussed separately, and hence are also not shown here. The 6D values calculated for formation waters in equilibrium with the 10/~ clay minerals from the Viking Formation are a reasonable match to actual compositions. In con- trast, oxygen-isotope equilibrium has not been established between these phases at present subsurface temperatures.

With two exceptions, calculated and measured bD and blSO values compare well for formation waters from the Belly River/Brazeau Groups, including the basal Belly River sandstone. However, this close approach to oxygen and hydrogen isotopic equilibrium may not be the result of post-crystallization

isotopic exchange. Diagenetic 10/~ clay minerals are among the very last major diagenetic phases formed in these rocks (Fig. 4; AYALON and LON6STAFFE, 1988). This means that their isotopic compositions could reflect neoformation from formation waters not greatly evolved from those currently present in the unit.

The very low diD values of 10 ,~, clay minerals (<0.2 #m size-fraction) from shale laminations in the Viking Formation ( -124 to -115%o, Table 2) and Belly River/Brazeau Groups ( -133 to -1297/oo, Table 2) are virtually identical to diagenetic 10 ~ clay minerals from the sandstones, and very much lower than commonly reported for detrital clay minerals ( ~ - 8 0 to -25%0; e.g. SAVIN and EPSTEIN, 1970a; LAWRENCE and TAYLOR, 1971, 1972; HASSANIPAK and ESLIN6ER, 1985). In addition, the 6180 values of 10 ,~ clay minerals (<0.2pm size-fraction) from these shales (+12.6 to 14.8%o; Table 2) are much lower than common for detrital illitic clays from major Cretaceous shale units in the western Canada sedimentary basin (Bearpaw, Colorado, Lea Park, Joli Fou and Clearwater shales; +16 to +19%o; LON6- STARVE, 1983, 1984, 1986 and unpublished data). The isotopic compositions of <0 .2pm 10 .A clay minerals in the sandstone-enclosed shale laminations may reflect diagenetic clay formation involving dissolution- precipitation reactions during conversion of smectite to illite in the presence of low blSo and low bD pore waters.

An alternative explanation of the hydrogen- isotope data for the diagenetic kaolinite and 10 A clay minerals is that they all crystallized from formation

Table 2. Stable isotope results for illite and l/S: Viking Formation, and Belly River and Brazeau Groups

Depth 6 D%o b x SO%o Sample location (m) Rock type SMOW SMOW

Viking Formation 7- i 4-37-6 W5* 2 3 8 6 . 9 Medium-grained sandstone - 132 15.5 6-1-39-7 W5 2404.6 Fine-grained sandstone - 107 14.4 7-32-34-6 W5 2719.1 Fine-grained sandstone - 120 14.3 14-30-31-28 W4 1872.6 Fine -grained sandstone - 110 14.7 11-11-35-3 W5 2083.5 Shale - 115 14.8 10-13-35-4 W5 2181.8 Shale -124 13.3

(Basal) Belly Riversandstone, Bel~ River Group 6-10-46-27W4 882.9 8-11-46-7W5 1269.9 4-22-47-2W5 978.0 12-21-47-15W5 2078.3 Red Deer River outcrop Crowsnest River outcrop

Bel~ Rive~ Brazeau Groups (continental sequence) 6-29-41-27W4 975.4 6-29-41-27W4 986.9 4-35-41-5W5 1345.7 6-19-46-5W5 1056.1 12-16-47-15W5 2093.4 14-28-46-7W5 1040.3

Medium-grained sandstone Medium-grained sandstone Medium-grained sandstone Medium-grained sandstone Medium-grained sandstone Medium-grained sandstone

-138 11.3 -133 9.1 -128 11.8 - 126 12.0 - 1 3 6 1(/.5 -131 11.9

Shale -133 12.6 Very fine-grained sandstone - 129 11.9

Fine-grained sandstone - 129 11.9 Medium-grained sandstone - 123 7.9

Shale - 129 nd Medium-grained sandstone - 138 12.4

nd = Not determined. *Well-locations as described in Table 1.


(a)

(b)

0

-20

-4o Viidng water

-60 ~ . . . _ _ 1 ~, -107 perrnill, Viking I/S

C -80 ~ -123 pcrmill, Belly River/ "~ Brazeau i/S

-120 ~ -132 permill, Viking I/S permill, Belly River/

-140 Belly River water Brazeau I/S

- 1~0 I I , i , I , I I

0 20 40 60 80 100 120 140

!2 0

-2

-10 0

mO -12

~,o -14

-16 0

Temperature (°C)

.......... //,~--~ +14.3 DcrlRill, Viking I/S

~ j f / ~ , f ~ +7~gpcrmill, Belly River/ ~lW",qr~--- Viking w~ter arazeau I/S

V / . . . . . . , , , , 20 40 60 80 i00 120 140

Temperature (°C) FIG. 9. Comparison of calculated and measured 6D (Fig. 9a) and 6180 (Fig. 9b) values for formation waters from the Vikin~Formation and Belly River/Brazeau Groups, including the basal Belly River sandstone: data for 10 A clay minerals. The temperatures and compositions of existing formation-water samples are as in Fig. 6: + = Belly River Group formation waters; • = Viking Formation formation waters. The calculated curves for the formation-water compositions were determined using the hydrogen- isotope I/S-water equation of YEH (1980), the oxygen-isotope l/S-water equation of SAVIN and LEE (1988) (assuming an average illite layer content of 80%), and the maximum and minimum 6D and 6'~O values, respectively, for 10 ,~ clay minerals from each unit (heavy lines, Viking Formation; light lines, Belly

River/Brazeau Groups).

waters with very similar (and very low) 6D values but variable 6180 compositions. This interesting scenario cannot be entirely ruled out. However, it is particularly difficult to envisage crystallization of the early diagenetic kaolinite in the Viking Formation from such D-depleted, yet 1SO-rich formation waters. When all the clay data are considered, it also seems unlikely that the close agreement between measured 6D values for the formation waters and those calculated assuming equilibration at present reservoir temperatures is only coincidence. Nevertheless, additional studies of natural systems where large contrasts in 6D values can be demonstrated between present formation waters and the paleo-pore waters from which clay minerals have crystallized should provide valuable, further tests of the hydrogen- isotope exchange hypothesis.

CONCLUSIONS

The results of this study suggest that diagenetic kaolinite in sandstones can re-equilibrate hydrogen isotopes with formation waters to temperatures at least as low as 40°C. Because this isotopic exchange is unaccompanied by significant changes in the original oxygen-isotope composition of the kaolinite, we be- lieve that it occurred in the absence of dissolution- precipitation reactions. This behaviour lends further support to the idea that proton exchange reactions may control the hydrogen-isotope compositions of many clay minerals in low temperature clay-water systems.

Diagenetic 10 A clay minerals (illite and illite/ smectite) also appear to be readily susceptible to hydrogen isotopic exchange with formation waters.

g

M t a

ell

E &

H isotopes in Cretaceous diagenetic clays, Alberta Basin

40 / meteoric

20 water line

o / O SMOW

-20

-40 Formation -60 water, Viking •

-80 x

-tO0

-120 ation water, -140 ~ Belly River

- 160 . . / ~ . . . . , . . . . ~ . . . . ~ . . . . , . . . , ~ . . . . ~ . . . .

-25 -20 -15 -10 -5 0 5 10 15 11

6 O of formation water, permill

- - meteoric water line • Standard Mean Ocean Water

Calculated Viking water Calculated basal Belly River water Calculated Belly River/Brazeau water

FIG. 10. Comparison of calculated and measured oxygen- and hydrogen-isotope compositions for formation waters from the Viking Formation and Belly River/Brazeau Groups, including the basal Belly River sandstone: results for diagenetic 10,~ clay minerals. Boxes outline the range of measured compositions for formation waters from the Viking Formation and Belly River Group, and local surface water in the study areas (see Fig. 7). Individual data points are formation water compositions calculated assuming complete oxygen and hydrogen isotopic equilibrium between each diagenetic 10 ,~ clay sample and formation water at the present subsurface temperature of that locality. Calculations have been

performed using isotopic geothermometers listed in Fig. 9.

667

In some cases, this re -equi l ib ra t ion may reflect a s imple p r o t o n exchange , not involving oxygen. In o the r cases, isotopic exchange has affected bo th hydrogen- and oxygen- iso tope composi t ions , sugges- t ing tha t the exchange process is dr iven by a mineral - ogical reac t ion (smect i te to illite t r ans fo rmat ion) .

Acknowledgements--Grants in aid of this research were received from the Natural Sciences and Engineering Re- search Council of Canada (NSERC A7387). We thank D. Caird for assistance with the oxygen-isotope analyses, and Dr T. K. Kyser and the isotope laboratory at the University of Saskatchewan for assistance with the H-isotopes analyses. We also thank Michael Bird, lan Hutcheon and Paul Lundegard for their helpful suggestions concerning an earlier draft of the manuscript, and Yousif Kharaka for meticulous editorial assistance.

Editorial handling: Y. K. Kharaka.

REFERENCES

AVALON A. and LONGSTAFFE F. J. (1988) Oxygen-isotope studies of diagenesis and pore water evolution in the western Canada sedimentary basin: evidence from the Upper Cretaceous basal Belly River sandstone, Alberta. J. Sediment Petrol. 58,489-505.

BEAUMONT C. (1981) Foreland basins. Geophys. J. Royal Astron. 65,291-329.

BEAUMONT E. A. (1984) Retrogradational shelf sedimen- tation: Lower Cretaceous Viking Formation, central Alberta. In Siliciclastic Shelf Sediments (eds R. W. TILL- MAN and C. T. SIEMERS), Soc. Econ. Paleontologists Mineralogists Spec. Paper 34, 163-177.

BIGELEISEN J. , PEARLMAN M. L. and PROSSER H. C. (1952) Conversion of hydrogenic materials to hydrogen for isotopic analysis. Anal. Chem. 24, 1356--1357.

BIRD M. 1. and CHIVAS A. R. (1988) Stable-isotope evidence for low-temperature kaolinitic weathering and post- formational hydrogen-isotope exchange in Permian kao-

linites. Chem. Geol. (Isotope Geosciences Section) 72, 249-265.

CLAVrON R. N. and MAYEDA T. K. (1963) The use of bromine pentafluoride in the extraction of oxygen from oxides and silicates for isotopic analysis. Geochim. Cos- mochim. Acta 27, 43-52.

CONNOLLY C. A., WALTER L. M., BAADSGAARD H. and LONGSTAFFE F. J. (1990) Origin and evolution of formation waters, Alberta Basin, western Canada sedimentary basin. II. Isotopic systematics and water mixing. Appl. Geochim. 5,397-413.

CRAIG H. (1961a) Standards for reporting concentrations of deuterium and oxygen-18 in natural waters. Science 133, 1833-1834.

CRAIG H. (1961b) Isotopic variations in meteoric waters. Science 133, 1702-1703.

DICKINSON W. R. and SNYDER W. S. (1978) Plate tectonics of the Laramide Orogeny. In Laramide Folding Associ- ated with Basement Block Faulting in the Western United States (ed W. MATHEWS), Geol. Soc. Am. Mem. 151,355- 366.

ESLINGER E. V. and YEn H-W. (1981)Mineralogy, o lS/o 16 and D/H ratios of clay-rich sediments from Deep Sea Drilling Project site 180, Aleutian Trench. Clays Clay Min. 29, 309-315.

HASSANIPAK A. A. and ESLINGER E. V. (1985) Mineralogy, crystallinity, 180/160, and D/H of Georgia kaolins. Clays Clay Min. 33, 99-106.

HEIN F. J., DEAN, M. E., DEIURE A. M., GRANT, S. K., ROBB G. A. and LONGSTAFFE F. J. (1986) The Viking Formation in the Caroline, Garrington and Harmattan East fields, western south-central Alberta: sedimento- logy and paleography. Bull. Can. Petrol. Geol. 34, 91- 110.

HITCHON B. (1984) Geothermal gradients, hydrodynamics, and hydrocarbon occurrences, Alberta, Canada. Am. Assoc. Petrol. Geol. Bull. 68,713-743.

HITCHON B. and FRIEDMAN I. (1969) Geochemistry and origin of formation waters in the western Canada sedimentary basin--I. Stable isotopes of hydrogen and oxygen. Geochim. Cosmochim. Acta 33, 1321-1349.

IWUAGWU C. J. and LERBEKMO J. F. (1982) The petrology of the basal Belly River sandstone reservoir, Pembina Field, Alberta. Bull. Can. Petrol. Geol. 30, 187-207.

IWUAGWU C. J. and LERBEKMO J. F. (1984) Application of

668 F.J . Longstaffe and A. Ayalon

outcrop information to subsurface exploration for sandstone reservoirs: basal Belly River Formation (Upper Cretaceous), Alberta foothills. In The Mesozoic o f Middle North America (eds D, F. STOTT and D. J. GLASS), Can. ~oc. Petrol. Geol. Mere. 9, 387-400.

JAMES A. T. and BAKER D. R. (1976) Oxygen isotope exchange between illite and water at 22°C. Geochim. Cosmochim. Acta 40, 235-239.

KHARAKA Y. K. and CAROTHERS W. W. (1986) Oxygen and hydrogen isotope geochemistry of deep basin brines. In Handbook o f Environmental Isotope Geochemistry (eds P. FRITZ and J.Ch. FONTES), Vol. 2, Chap. 8, pp. 305-360. Elsevier.

KYSER T. K. (1987) Equilibrium fractionation factors for stable isotopes. In Stable Isotope Geochemistry of Low Temperature Fluids (ed. T. K. KYSER), VO1. 13, Chap. i, pp. 1-84. Mineralogical Association of Canada Short Course.

KYSER T. K. and O'NEIL J. R. (1984) Hydrogen isotope systematics of submarine basalts. Geochim. Cosmochim. Acta 48, 2123-2133.

LAMBERT S. J. and EPSTEIN S. (1980) Stable isotope investi- gations of an active geothermal system in Valles Caldera, Jemez Mountains, New Mexico. J. Volcanol. Geotherm. Res. 8, 111-129.

LAND L. S. and Du-r'roN S. P. (1978) Cementation of a Pennsylvanian deltaic sandstone: isotopic data. J. Sedi- ment. Petrol. 48, 1167-1176.

LAWRENCE J. R. and TAYLOR H. P., Jr. (1971) Deuterium and oxygen-18 correlation: clay minerals and hydroxides in Quaternary soils compared to meteoric waters. Geo- chim. Cosmochim. Acta 35,993-1003.

LAWRENCE J. R. and TAYLOR H. P. Jr. (1972) Hydrogen and oxygen isotope systematics in weathering profiles. Geo- chim. Cosmochim. Acta 36, 1377-1393.

Llu K-K. and EPSTEIN S. (19841 The hydrogen isotope fractionation between kaolinite and water. Isotope Geosei. 2, 335-350. Chem. Geol. 46, 335-350.

LONGSTAFFE F. J. (1983) Diagenesis, IV. Stable isotope studies of diagenesis in clastic rocks. Geoscience Canada 10, 44-58,

LONGSTAFFE F. J. 11984) The role of meteoric water in diagenesis of shallow sandstones: stable isotope studies of the Milk River aquifer and gas pool. In Clastic Diagenesis (eds R. C. SUROAM and D. A. MACDONALD), Am. Assoc. Petrol. Geol. Mere. 37, 81-98.

LONCSTAFFE F. J. (1986) Oxygen isotope studies of diagenc- sis in the basal Belly River sandstone, Pembina I-Pool, Alberta. J. Sediment. Petrol. 56, 78-88.

LONGSTAFFE F. J. (1987) Stable isotope studies of diagenetic processes. In Stable Isotope Geochemistry o f Low Tem- perature Fluids" (ed. T. K. KYSER), Vol. 13, Chap. 5, pp. 187-257. Mineralogical Association of Canada Short Course.

LONGSTAFFE F. J. (1989) Stable isotopes as tracers in clastic diagenesis. In Burial Diagenesis (ed. I. E. HUTCHEON), VOI. 15, Chap. 6, pp. 201-277. Mineralogical Association of Canada.

LONGS'IAFFE F. J. and AYALON A. (1987) Oxygen-isotope studies of clastic diagenesis in the Lower Cretaceous Viking Formation, Alberta: implications for the role of meteoric water. In The Diagenesis of Sedimentary Se- quences (ed. J. D. MARSHALL), Geol. Soc. Spec. Pub. 36, 277-296.

LUNDEGARD P. (1989) Temporal reconstruction of sandstone diagenetic histories. In Burial Diagenesis (ed. J. E. HUTCHEON), Vo]. 15, Chap. 6, pp. 181-200. Mineralogi- cal Association of Canada.

O'NEIL J. R. (1987) Preservation of H, C, and O isotopic ratios in the low temperature environment. In Stable Isotope Geochemistry of Low Temperature Fluids (ed. T. K. KYSER), Vol. 13, Chap. 2, pp. 85-128. Mineralogical Association of Canada Short Course.

O'NEIL J. R. and KHARAKA Y. F. (1976) Hydrogen and oxygen isotope exchange reactions between clay minerals and water. Geochim. Cosmochim. Acta 40, 241-246.

RAHMANI R. A. and LERBEKMO J. F. (1975) Heavy mineral analysis of Upper Cretaceous and Paleocene sands in Alberta and adjacent areas of Saskatchewan. In The Cretaceous System in the Western Interior of North Amer- ica (ed. W. G. E. CALDWELL), Geol. Assoc. Canada Spec. Paper 13,607-633.

SAVlN S. M. and EPSTEIN S. (1970a) The oxygen and hydrogen isotope geochemistry of clay minerals. Geochim. Cosmochim. Acta 34, 25-42.

SAVlN S. M. and EPSTEIN S. (1970b) The oxygen and hydrogen isotope geochemistry of ocean sediments and shales. Geochim. Cosmochim. Acta 34, 43-63.

SAVIN S. M. and LEE M. (1988) Isotopic studies of phyllosilicates, in Hydrous Phyllosilicates (Exclusive of Micas) (ed. S. W. BAILEY), Reviews in Mineralogy 19, 189-223.

SAVIN S. M. and YEH H-W. (1981) Stable isotopes in ocean sediments. In The Oceanic Lithosphere (ed. C. EMI- LIANI), The Sea 7, 1521-1554. John Wiley and Sons.

SHOULDICE J. R. (1979) Nature and potential of Belly River gas sand traps and reservoirs in western Canada. Bull. Can. Petrol. Geol. 27, 229-241.

SUZUOK1 T. and EPSTEIN S. (1976) Hydrogen isotope fractionation between OH-bearing minerals and water. Geo- chim. Cosmochim. Acta 40, 1229-1240.

TAYLOR R. S., MATHEWS, W. H. and KUPSCH W. O. (1964) Tertiary. In Geological History of Western Canada (eds R. G. MCCROSSAN and R. P. GLAISTER), Alberta Soc. Petrol. Geol. 190-194.

TILLEY B. J. and LONGSTAFFE F. J. 119891 Diagenesis and isotopic evolution of porewaters in the Alberta Deep Basin: the Falher Member and Cadomin Formation. Geochim. Cosmochim. Acta 53, 2529-2546.

WEIMER R. J. (1983) Relation of unconformities, tectonics, and sea level changes: Cretaceous of the Denvcr Basin and adjacent areas. In Mesozoic Paleogeography of West- central United States" (eds M. W. REYNOLDS and E. D. DOLLY), pp. 359--376. Rocky Mountain Section, Soc. Econ. Paleontologists Mineralogists.

WHITNEY G. and NORTHROP H. R. (1988) Experimental investigation of the smectite to illite reaction: dual reaction mechanisms and oxygen-isotope systematics. Am. Mineral. 73, 77-91/.

WILLIAMS G. D. and BURKE C. F., Jr. (1964) Upper Creta- ceous. In Geological History of Western Canada (eds. R. G. McCROSSAN and R. P. GLAISTER), Alberta Soc. Petrol. Geol. 169-189.

WILLIAMS G. D. and STELCK C. R. (19751 Speculations on the Cretaceous paleogeography of North America. In The Cretaceous System in the Western Interior of North America (ed. W. G. E. CAtA)WELL), Geol Assoc. Canada Spec. Paper 13, 1-7.

WILSON M. R., KYSER T. K., MEHNERT H. H. and HOEVE J. 11987) Changes in the H-O-Ar isotope composition of clays during retrograde alteration. Geochim. Cosmo- chim. Acta 51,869-878.

YEH H-W. (1980) D/H ratios and latc-stage dehydration of shales during burial. Geochim. Cosmochim. Acta 44, 341-352.

YEn H-W. and EPSTEIN S. (1978) Hydrogcn isotope exchange between clay minerals and sea water. Geochim. Cosmochim. Acta 42, 140-143.

YEH H-W. and ESLINGER E. V. (1986) Oxygen isotopes and the extent of diagenesis of clay minerals during sedimen- tation and burial in the sea, Clays Clay Min. 34,403-406.

YEn H-W. and SAVIN S. M. 11976) The extent of oxygen isotope exchange between clay minerals and sea water. Geochim. Cosmochim. Acta 40, 743-748.

YEH H-W. and SAVIN S. M. (1977) Mechanism of burial metamorphism of argillaceous sediments: 3. O-isotope evidence. Bull. Geol. Soc. Am. 88, 1321-1330.

Hydrogen-isotope geochemistry of diagenetic clay minerals from Cretaceous sandstones, Alberta,...

Documents

Transcript of Hydrogen-isotope geochemistry of diagenetic clay minerals from Cretaceous sandstones, Alberta,...