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Ministry of Northern Development and Mines Ontario

ONTARIO GEOLOGICAL SURVEY Open File Report 5743

Ontario Geoscience Research Grant Program, Grant No. 249

Geochemistry of Formation Waters, Southwestern Ontario, Canada and Southern Michigan U.S.A.: Implications for Origin and Evolution

By

RS. Dollar, S.K. Frape and R.H. McNutt

1991

Parts of this publication may be quoted if credit is given. It is recommended that reference to this publication be made in the following form: Dollar, P.S., Frape, S.K. and McNutt, R.H. 1991. Geochemistry of Formation Waters, Southwestern Ontario, Canada and Southern Michigan U.S.A.: Implications for Origin and Evolution, Ontario Geoscience Research Grant Program, Grant No. 249; Ontario Geological Survey, Open File Report 5743, 72p.

Queen©s Printer for Ontario, 1991

Ontario Geological Survey

OPEN FILE REPORT

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The right to reproduce this report is reserved by the Ontario Ministry of Northern Development and Mines. Permission for other reproductions must be obtained in writing from the Director, Ontario Geological Survey.

V.G. Milne, Director Ontario Geological Survey

©UNEDITED MANUSCRIPT" iii

FOREWORD

This publication is a final report of a research wide distribution, but rather to encourage the project that was funded under the Ontario recipients of grants to seek publication in ap Geoscience Research Grant Program. A re propriate scientific journals whenever possi quirement of the Program is that recipients are ble. The Survey, however, also has an to submit final reports within six months after obligation to ensure that the results of the termination of funding. research are made available to the public at an early date. Although final reports are the A final report is designed as a comprehensive property of the applicants and the sponsoring summary stating the findings obtained during agencies, they may also be placed on open file. the tenure of the grant, together with support This report is intended to meet this obligation. ing data. It may consist, in part, of reprints or preprints of publications and copies of ad No attempt has been made to edit the report, dresses given at scientific meetings. the content of which is entirely the responsi bility of the author(s). It is not the intent of the Ontario Geological Survey to formally publish the final reports for

V.G. Milne Director Ontario Geological Survey

©UNEDITED MANUSCRIPT

TABLE OF CONTENTS

Abstract...... xiii Introduction ...... 1 Purpose And Scope ...... l Area Of Study ...... 3 Previous Work ...... 4 Subsurface Water Nomenclature ...... 4 Sampling Procedures And Analytical Methods ...... 5 Sampling Procedures ...... 5 Well Head Bleeder Valve ...... 5 Cable Tool Bailers ...... 5 Drill Stem Tests ...... 5 Production Tanks And Separators ...... 5 Dundee Samples, Southwestern Ontario ...... 6 Analytical Procedures ...... 6 Geology ..... -...... 7 Stratigraphic And Structural Controls ...... 7 Structural Setting...... 7 Geological Framework ...... © .7 Cambrian Period ...... 7 Mount Simon And Eau Claire ...... 9 Ordovician ...... 10 Prairie Du Chien ...... 11 Trenton And Black River Groups ...... 11 Silurian ...... 11 Silurian Sandstones ...... 11 Cataract And Clinton Groups ...... 11

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a) Whirlpool Formation ...... 11 b) Grimsby Formation ...... 11 c) Thorold Formation ...... 11 Silurian Carbonates ...... 12 Guelph/Niagaran Pinnacle Reefs ...... 13 Guelph Patch Reefs ...... 13 Salina Al Carbonate...... 13 Salina Unit Salts ...... 14 Salina A2 Salt...... 14 SalinaFSalt ...... 14 Devonian ...... 14 Dundee Formation ...... 14 Richfield Zone, Lucas Formation ...... 14 Mississippian ...... 14 Berea Sandstone ...... -...... 14 Stable Isotopes: Oxygen And Hydrogen ...... 15 Introduction ...... 15 Terminology ...... 15 8 - Notation ...... 15 Standard Mean Ocean Water ...... ,...... 15 Meteoric Water ...... 15 Results ...... 15 Cambrian ...... 16 Ordovician ...... 16 Prairie Du Chien ...... 16 Trenton and Black River Groups ...... 16 Silurian ...... 17 Silurian Sandstones ...... 17 Silurian Carbonates ...... 17 Silurian Salts ...... 17 Devonian ...... 17 Dundee Formation ...... 17 Mississippian ...... 18

viii "UNEDITED MANUSCRIPT

Discussion ...... 18 Possible Interpretations ...... 18 Present Study ...... 20 Isotopic Evolution Of individual Units ...... 20 Water Chemistry ...... 25 Chemical Characteristics ...... 25 Discussion ...... 26 Alkali Metals (Na, K) ...... 27 Alkaline Earth Metals (Ca, Mg, Sr) ...... 29 Sulphate ...... 31 Halogens (CI, Br) ...... 31 Carpenter©s Sea Water Evolution Model...... 33 Strontium Isotopes ...... 39 Introduction ...... 39 Brine Signature And Seawater Sr ...... 39 Variations In Sr Isotopic Values ...... 41 Mineral And Rock Sr Data ...... 45 Summary ...... 47 References ...... 49

List of Appendices Appendix I - Subsurface Water Nomenclature Definitions ...... 59 Appendix n - Chemical And Isotopic Data ...... 61 Appendix HI - Dissemination Of Results ...... 71

List of Tables Table 1. Dominant reservoir lithologies for stratigraphic units sampled in southwestern Ontario and southern Michigan...... 3 Table 2. Groundwater classification based on total dissolved solids concentrations...... 4 Table 3. Water classification and dominant ions...... 25

List of Figures Figure 1. Water sampling sites, southwestern Ontario, Canada and southern Michigan, U.S.A...... 2

©UNEDITED MANUSCRIPT© ix

Figure 2. Schematic representation of the Paleozoic strata, eastern Michigan and northern Appalachian Basins...... 2 Figure 3. Regional tectonic structures influencing the Paleozoic strata of southern Michigan and southwestern Ontario...... 8 Figure 4. Conceptual fracture framework, southwestern Ontario...... ,. .8 Figure 5a. Generalized stratigraphic succession, southwestern Ontario...... 9 Figure 5b. Generalized stratigraphic succession, Michigan Basin, U.S.A...... 10 Figure 5c. Generalized stratigraphic succession, Niagara Peninsula and eastern Lake Erie, Ontario...... 12 Figure 6. Schematic stratigraphy of a Middle Silurian pinnacle reef and encasing evaporite units...... 13 Figure 7. Oxygen and hydrogen isotopic compositions of all formation waters from the present study...... 16 Figure 8. Oxygen and hydrogen isotopic compositions of brines displaying individual groupings by reservoir age...... 17 Figure 9. Oxygen and hydrogen isotopic interpretations by: a) Clayton et al. (1966); b) Hitchon andFriedman (1969); and c) Hosier (1979)...... 19 Figure 10. Trajectories for sea water undergoing evaporation superimposed over data from the present study...... 21 Figure 11. Oxygen isotope composition versus TDS concentration...... 22 Figure 12. CI concentration versus sample depth...... 26 Figure 13a. Na/Cl ratios of formation waters as a function of their chloride content...... 27 Figure 13b. K/C1 ratios of formation waters as a function of their chloride content...... 28 Figure 13c. Ca/Cl ratios of formation waters as a function of their chloride content...... 29 Figure 13d. Mg/Cl ratios of formation waters as a function of their chloride content...... 30 Figure 13e. Sr/Cl ratios of formation waters as a function of their chloride content...... 31 Figure 13f. SO^Cl ratios of formation waters as a function of their chloride content...... 32 Figure 13g. Br/Cl ratios of formation waters as a function of their chloride content...... 32 Figure 14. Concentrations of MCk relative to Br...... 34 Figure 15. Concentration trends of ions in sea water relative to Br during evaporation and precipitation...... 34 Figure 16. Concentration trend of CI in sea water relative to Br during evaporation and precipitation of halite and carnallite...... ; .35 Figure 17. Concentration trend of Na in sea water relative to Br during evaporation and precipitation of halite...... 36

©UNEDITED MANUSCRIPT"

Figure 18. Concentration trend of Ca and SO4 in sea water relative to Br during evaporation and precipitation of calcium sulphate...... 37 Figure 19. Concentration trend of Mg in sea water relative to Br during evaporation and precipitation of magnesium sulphate and carnallite...... 37 Figure 20. Concentration trend of K in sea water relative to Br during evaporation and precipitation of carnallite...... 38 Figure 21. Strontium isotopic composition of brines from the Michigan and northern Appalachian Basins...... 40 Figure 22. Strontium isptopic composition versus Cl/Sr concentration of Michigan and northern Appalachian! Basin brines. .. *...... 41 Figure 23. Strontium versus oxygen isotopic values of brines from the Michigan and northern Appalachian Basins...... 42 Figure 24. Strontium versus deuterium isotopic values of brines from the Michigan and northern Appalachian Basins...... 43 Figure 25. Sr isotopic composition versus reservoir age displaying groupings of Ordovician reservoirs by individual fields...... 44

©UNEDITED MANUSCRIPT" xi

ABSTRACT

Formation waters from Paleozoic strata in in 818O - 82H space, typical for sedimentary southwestern Ontario and southern Michigan basin brines. All waters have negative 82H were analyzed for major, minor and trace ele values and positive to negative 818O values ment geochemistry; stable isotope composi relative to Standard Mean Ocean Water tion of oxygen and hydrogen; tritium content; (SMOW). The concentrated brines from each and strontium isotopic composition. Waters stratigraphic horizon plot within unique nar from two salt mines and approximately 120 row ranges of isotopic composition. The only wells from nine hydrocarbon producing for exceptions are the two low salinity samples mations ranging in age from Cambrian to from the Dundee Formation (Devonian) in Mississippian were collected. southwestern Ontario which are depleted in Most formation waters are brines that contain 818O and 82H, indicative of cooler climatic between 140 and 391 g/1 Total Dissolved Sol conditions. The differences in isotopic com ids (TDS), the only exceptions are the dilute position both within and between the units saline and brackish waters from the Dundee result from: 1) different initial isotopic com Formation in southwestern Ontario. Most positions, 2) mixing of isotopically different brines are Ca-Na-Cl in composition, although waters, 3) membrane filtration, and 4) differ some variation in Ca/Na ratios does occur. ent isotope fractionation processes acting on The dissolved solids concentrations of these the various waters. The present-day isotopic waters are derived from: 1) infiltration and distribution is much more complicated than burial of evaporated sea water, 2) subsurface was previously believed and may represent dissolution of halite, and 3) membrane filtra several independent hydrologic systems. tion. Later modification of the chemical com position is the result of diagenesis (rock water ^Sr/^Sr ratios of the waters vary from 0.7080 interaction, mineral precipitation,...) and mix to 0.7112. With the exception of those of the ing with waters of different chemical compo salt units of the Salina Formation (Silurian), sitions. most values are greater than the corresponding Paleozoic seawater values, indicative of rock Stable isotopes of oxygen and hydrogen indi water interaction. The source of the radio cate that all waters plot below and to the right genic Sr in these waters has not been identi of the Global Meteoric Water Line (GMWL) fied.

XIII

Geochemistry of Formation Waters, Southwestern Ontario, Canada and Southern Michigan, U.S.A. Implications for Origin and Evolution

by

RS. Dollar1, S.K. Frape1 and RK McNutt2

1 Department of Earth Sciences, University of Waterloo, Waterloo, Ontario, N2L 3GI 2 Department of Geology, McMaster University, Hamilton, Ontario, L8S 4MI

INTRODUCTION The dissolved constituents in formation wa ters may also cause mineral scaling and cor Waters with high salinities are commonly as rosion of oil field production equipment. sociated with oil, gas and metallic mineral deposits in sedimentary basins. Although oc currences of these waters are well docu PURPOSE AND SCOPE mented, the sources of the water molecules and dissolved chemical species in many basi- This study was undertaken to determine the nal brines have not been unequivocally re chemical and isotopic composition of forma solved, despite decades of debate tion waters in sedimentary rocks of the Michi (Hanor,1983). Knowledge of the origin and gan and northern Appalachian Basins. The evolution of these waters is of considerable sampling program was designed to collect interest at the present time for the develop waters from the various lithologic units cur ment of models for: (i) hydrocarbon source rently producing hydrocarbons in the basins rock potential; (ii) Mississippi Valley Type for the purpose of identifying any regional Pb-Zn ore deposition; and (iii) waste disposal compositional trends. The waters were ana strategies. lyzed for major and minor elements, stable isotope composition of oxygen and hydrogen; Formation water chemical compositions are tritium content, and strontium isotopic com also important with respect to a variety of position. These analyses would permit: 1) environmental and economic issues. Knowl identification of differences in regional water edge of formation water salinities is, for ex compositions, and (or) 2) identification of ample, vital for calibration of electric logs that trends within and between formations that are used to determine petrophysical parame may be used as source formation indicators to ters, production zones and hydrocarbon re identify production and pollution related serves. Casing leaks from fluid-bearing problems. horizons other than the producing zone may be identified if there is sufficient variability in There is currently considerable research inter the chemical and/or isotopic compositions of est focused on models to predict the origin and the two zones. Also, since mineral solubility evolution of sedimentary basin brines. The is a function of solution composition, forma present study reviews some of the current tion waters can play an important role in res theories as they apply to the Michigan and ervoir porosity and permeability distributions. northern Appalachian Basins. As later dis-

VNEDITED MANUSCRIPT© A1 CARBONATE©ir*© ,© s Sf^ipxr^i GUELPH/ NIAGARAN/ - L * i ^^ L* /T * J

THOROLD GRMS8Y WHIRLPOOL

50 100 km

Figure 1. Water sampling sites, southwestern Ontario, Canada and southern Michigan, U.S.A.

NW SE MICHIGAN APPALACHIAN BASIN BASIN

PRECAMBRIAN ARCH

Q- QUATERNARY M- MISSISSIPPIAN BEREA O- DEVONIAN DUNDEE RICHFIELD S- SILURIAN F SALT A-2 SALT GUELPH X NIAGARAN THOROLD-GRIMSBY WHIRLPOOL O- ORDOVICIAN TRENTON-BLACK RIVER PRAIRIE DU CHIEN e- CAMBRIAN (UNDIVIDED)

Figure 2. Schematic representation of the Paleozoic strata, eastern Michigan and northern Ap palachian Basins. Relative positioning of the hydrocarbon reservoirs is also shown.

©UNEDITED MANUSCRIPT cussions illustrate, the formation waters pri ness, ranges in age from Early Cambrian to marily reflect present-day hydrogeochemical Late Jurassic. The present study determines and hydrogeological conditions in the basin. the characteristic inorganic chemical constitu Unless otherwise stated, all samples referred ents in groundwaters from several hydrocar to in the text are water samples. bon-bearing horizons and two salt mines located in southwestern Ontario and Michigan (Table 1). AREA OF STUDY The area of study extends westward from PREVIOUS WORK Oxford County, Ontario, Canada in the east to Missaukee County, Michigan, U.S.A. (Figure Formation waters in the Michigan Basin were 1). In the eastern part of the study area, the first discussed in a series of papers by Clay ton Phanerozoic is represented by 875 m of strata et al. (1966), Graf et al. (1965), and Graf et that is Late Cambrian to Late Silurian in age. al. (1966). These studies were based on 26 The sedimentary units generally thicken to formation water samples from southwestern wards the depocentre of the Michigan Basin Ontario and the southern peninsula of Michi where a much more complete sedimentary gan. Of the 26 waters collected, only five succession occurs (Figure 2). Li the central were from pre-Devonian age reservoirs. portion of the basin, the Phanerozoic sequence Clayton et al. (1966) concluded that these which is greater than 5 000 m in total thick waters were all meteoric in origin based on

Table 1: Dominant reservoir lithologies for stratigraphic units sampled in southwestern Ontario and southern Michigan.

Period Producing Location Lithology Interval

Mississippian Berea MI Sandstone

Devonian Dundee ONT/MI Carbonate Richfield MI Carbonate

Silurian F Unit ONT Salt A-2Unit ONT Salt Al/Guelph/Niagaran ONT/MI Carbonate Thorold/Grimsby ONT Sandstone Whirlpool ONT Sandstone

Ordovician Trenton-Black ONT/MI Carbonate River Prairie du Chien MI Sandstone

Cambrian (Undivided) ONT Sandstone

©UNEDITED MANUSCRIPT© stable hydrogen and oxygen isotope analyses. SUBSURFACE WATER These isotopic analyses were also used by NOMENCLATURE Graf et al. (1965) to crudely predict that fluid movement was dominantly upward in the A number of descriptive terms have been in Michigan Basin. Graf et al. (1966) suggested troduced to describe subsurface waters based the high salinities of these waters were the on salinity and origin. One of the simplest and result of membrane filtration occurring during most widely used classification schemes is the passage of water through shale micropore based on the Total Dissolved Solid (TDS) systems and dissolution of halite in units close concentration of a water (Table 2). to the Salina Salts. Some additional definitions commonly used throughout the literature and in this paper are listed in Appendix I.

Table 2. Groundwater classification based on total dissolved solids concentrations (after Carpenter (1978) modified from Davis (1964). The TDS of seawater is approximately 35 000 mgA.

Category TDS (mg/l)

Fresh Water 0-1000

Brackish Water 1000-10000

Saline Water 10000-100000

Brine MOO 000

©UNEDITED MANUSCRIPT© SAMPLING PROCEDURES AND ANALYTICAL METHODS

tool were generally poor sources of repre sentative formation water due to contamina All formation water samples were collected tion by drilling fluids. from wells drilled in the search for petroleum. Most samples were collected from wellhead PRODUCTION TANKS AND bleeder valves of producing wells. However, SEPARATORS a few cable tool bailer, drill stem test, separa tor and production tank samples were also Samples from Prairie du Chien gas wells in included for comparison. The advantages and central Michigan had to be collected from limitations of these sampling locations are separators due to the high reservoir pressures discussed below. involved and the relatively low daily brine production (approximately 0.5 m3 per day). WELL HEAD BLEEDER VALVE Physico-chemical changes to the Prairie du Chien samples resulting from their rise to the The wellhead bleeder valve samples should surface from depths in excess of 3650 m must provide the most representative samples, as be expected. A water sample from the In- they are collected as close to the source for nerkip gas field in Oxford County, Ontario mation as feasible. Therefore, these samples also had to be collected from a production tank will have physical and chemical properties due to the low daily brine production rate. It most similar to in situ formation fluids. was therefore assumed that the produced water was in fact water vapour that had con CABLE TOOL BAILERS densed as a result of pressure and temperature changes. Samples collected from cable tool bailers may be of excellent quality if production casing is Samples from gas wells in central and eastern set down to the producing aquifer. This pre Lake Erie were collected by company repre vents waters from overlying aquifers from sentatives from hoses attached to the well contaminating the sample. The bailer is low heads at the bottom of the lake. Air ered to the bottom of the hole, filled with compression equipment at the lake surface formation fluid and lifted to the surface where was used to remove well bore fluids from the sample is recovered. Fluid samples recov these wells. ered from cable tool drilled wells may be of relatively high quality since they are not A number of the preliminary Silurian Guelph drilled with drilling mud, a probable source of samples were collected by a company repre contamination. sentative from production tanks. These sam ples are of dubious quality since many of the DRILL STEM TESTS wells are known to have chemical and heat treatment facilities. Oxygen and hydrogen and Two samples from Cambrian strata were col isotopic data for these wells were deemed lected from Drill Stem Tests (DST©s) during unreliable and were not used. Only the chemi the drilling in areas where there is presently cal and Sr isotopic data proved to be repre no production. Samples collected from a DST sentative as shown by duplicate sample

©UNEDITED MANUSCRIPT© collection from the bleeder valves of selected hydrogen and strontium isotopic composition wells at a later date. and tritium content. Hydrogen and oxygen isotope ratios were measured by conventional DUNDEE SAMPLES, gas-source mass spectrometry. The oxygen SOUTHWESTERN ONTARIO analyses were performed by long term equili bration with COi, while hydrogen analyses The reliability of samples from the Devonian were done on water distilled from the brines of southwestern Ontario is uncertain owing to at elevated temperatures (4000C) to prevent the long production history of the fields and the formation of hydrated salts. Results were the large numbers of unrecorded and un reported with respect to the Vienna-SMOW plugged wells. A second difficulty lies in the standard. The precision was dbO.15%0 and fact that many of these fields have been water 2.50xfo for 18O and *H, flooded. The two samples from this study respectively. These were obtained by company representatives chemical and isotopic analyses were per from a production tank and a cable tool bailer formed at the University of Waterloo. during drilling. The ^Sr/^Sr ratios were measured on a VG- 354 mass spectrometer, following separation by standard ion exchange techniques. Elution ANALYTICAL PROCEDURES was carried out using 2.5N HC1. Dissolution of carbonate phases was done using ultra pure Prior to chemical analysis, samples were fil 0.5N HC1 or acetic acid at room temperature. tered in the laboratory through a 0.45 [Lm Gentle heating was necessary to dissolve hand-held "millipore" filter system. A 500 ml dolomite. Dissolution of SO4 was done with aliquot was acidified to a pH ^ using HC1, 6N HC1. The precision between runs of a before analysis for cations by atomic absorp single analysis of the ratio was dbO.003% (2 tion spectroscopy. A second filtered 500 ml sigma). Repeated runs of the E&A and NBS aliquot, not acidified, was used for CI, Br, and 987 standards gave average ratios of 0.70802 SO4 analysis by a Dionex Auto Ion System 12 and 0.71022, respectively. Sr analyses were liquid ion chromatograph. Filtered 125 ml performed at McMaster University, Hamil aliquots were used for analysis of oxygen, ton, Ontario.

©UNEDITED MANUSCRIPT" GEOLOGY

STRATIGRAPHIC AND to the southeast (Sanford et al., 1985). The STRUCTURAL CONTROLS current regional dip of the rocks to the north west of the arches is 6 to 9 m/km into the In order to appreciate the hydrogeochemical Michigan Basin; to the southeast of the arches, and fluid migrational aspects of the study, it is the dip is 6 m/km into the Appalachian Basin necessary to fully understand the important (Winder and Sanford, 1972). Paleozoic strata stratigraphic and structural controls that might in the Chatham Sag are for the most part influence fluid composition and movement in horizontal. the area. Sanford et al. (1985) proposed a relatively The Michigan Basin is a remarkably circular active tectonic history for southwestern On feature consisting of symmetrical bands of tario. Tectonically associated fault block re subcrop or outcrop that pass inward from an adjustment has provided the structural control exterior rim of Silurian carbonates to red beds for the origin and development of southwest of Jurassic age in the basin centre. Southwest ern Ontario©s hydrocarbon traps (Figure 4). ern Ontario and the southern peninsula of The implications of such tectonic movements Michigan are underlain by an essentially un on the hydrodynamic/fluid migration history disturbed sedimentary succession that rests and salt dissolution are discussed where ap unconformably on Precambrian basement propriate. rocks. Outcrops are largely obscured by Pleis tocene glacial drift that reaches thicknesses up to about 250 m. GEOLOGICAL FRAMEWORK

A brief description of the stratigraphic units STRUCTURAL SETTING and associated structural features are dis cussed below as they apply to the origin and The Michigan Basin is bounded by faulted evolution of formation waters. The reservoir Precambrian rocks of the Canadian Shield to rocks, ranging in age from Late Cambrian to the north and northeast, the Algonquin Arch Early Mississippian, are represented in the to the east and southeast, the Findlay and stratigraphic sections of southwestern Ontario Kankakee Arches to the south and southwest, and Michigan (Figure 5a,b). Formations from and the Wisconsin Arch to the west (Figure which water samples were obtained are dis 3). The Algonquin and Findlay Arches are cussed. broad Precambrian highs, separated by the Chatham Sag, that trend northeast-southwest, dividing the Ontario Peninsula into two parts. CAMBRIAN PERIOD These two positive structural features, prob ably introduced during Late Precambrian The oldest rocks that have yielded oil and gas time, and then intermittently reactivated dur in Ontario are Late Cambrian sandstones and ing the Paleozoic, form a broad platform be sandy dolostones. There is presently no pro tween a more rapidly subsiding Michigan duction of hydrocarbons from Cambrian age Basin to the west and the Appalachian Basin strata in Michigan.

©UNEDITED MANUSCRIPT O 50 100 km

Figure 3. Regional tectonic structures influencing the Paleozoic strata of southern Michigan and southwestern Ontario (modified from Ells, 1969).

Figure 4. Conceptual fracture framework, southwestern Ontario (Sanford et al., 1985).

8 ©UNEDITED MANUSCRIPT" METRES E.0-^ SUNBURY ————————j BIOHERMAL LOWER MISS. A L-w---- VBEREA DEVELOPMENT *2O2O ——\ BEDFORD UPPER 4. ^^a^v KETTLE POINT LIMESTONE ]DEVONIAN j i -200 HAMILTON GP. i ^S^P- MIDDLE -J-^ DUNDEE DOLOSTONE

j i DETROIT RIVER GP. i i SALT/ANHYDRITE LOWER ^7 ^^ BOIS BLANC &H* 1 i i r ——" BASS ISLANDS -f-f-. ——^ G UNIT ——V F UNIT ffi/!? E UNIT SANDSTONE |SILURIAN B s*0*^ D UNIT J UPPER \ C UNIT 3 OIL AND GAS B UNIT 2 PRODUCING ZONES UjLLll •# w ~ rfrrWlS TTTTTT1 A-2 UNIT TECTONIC -8OO T^Z * A-1 UNIT MOVEMENTS 4 MIDDLE ---T--—-~ LOWER J^fJ-J-. CATARACT GP. l ^z-z-E": -1000 QUEENSTON UPPER ^^^—"^^ GEORGIAN BAY A-2 UNIT 4 OOG*i BLUE ORDOVICIAN T'P'T MOUNTAIN -rSJ-r -12OO * TRENTON GP. A-1 UNIT MIDDLE j^j i K i ^GUELPH 1TLTL -1400 BLACK RIVER GP. i i GOAT ISLAND ^L i ^r L^ —————————— GASPORT UPPER CAMBRIAN x- r?.T: *T". ROCHESTER ^ x ^ \ PRECAMBRIAN ' BASEMENT ROCKS \ REYNALE8 GSC

Figure 5a. Generalized stratigraphic succession, southwestern Ontario (Sanford et al., 1985).

Mount Simon and Eau Claire the Algonquin Arch close to the northern ero sional pinchout edge of the Appalachian Ba The Mount Simon is the lowermost Upper sin. Towards the centre of the basin, there is Cambrian formation from which there is hy production from the Eau Claire Formation, drocarbon production. The rocks consist of which directly overlies the Mount Simon. white to light grey quartzose sandstones that The Eau Claire consists of fine to medium are locally conglomeratic at the base where grained sandstone that is interbedded with they overlie igneous and metamorphic Pre thinly bedded grey dolostone and shaley grey cambrian rocks (Sanford and Quillian, 1959). dolostone. Glauconite occurs locally. Hy Production of hydrocarbons from this unit is drocarbon accumulations in the Eau Claire dominantiy confined to the southern flank of

©UNEDITED MANUSCRIPT© SERIES/GROUP/FORMATION

Donunorr Lithology

EXPLANATION

Limestone

Anhydrite or Gyptum

PRECAMBRIAN

Figure 5b. Generalized stratigraphic succession, Michigan Basin, U.S.A. (modified from Ells, 1969).

Formation are dominantly fault controlled ORDOVICIAN (Sanford etal., 1985). For the purposes of this study, the Mount Overlying the Upper Cambrian sandstones Simon and Eau Claire formations will be and dolostones in southwestern Ontario is a grouped together and termed Cambrian sand sequence of Ordovician carbonates and stones. shales. In central and southern Michigan, the Ordovician strata consist of sandstones, car Large salt water flows frequently occur in bonates and shales. Water samples were col wells that penetrate these Late Cambrian aqui lected from the Prairie du Chien sandstone in fers, indicating that high porosity and perme the central portion of the Michigan Basin, and ability exist within these formations. from the Middle Ordovician carbonates of the

10 ©UNEDITED MANUSCRIPT" Trenton and Black River Groups in southern and the Niagaran Group in Michigan, and 3) Michigan and southwestern Ontario. the Salina A2 and F Unit salts. Data for two samples from the A2 Salt and one sample from Prairie du Chien the F Salt are from Miles (1985).

Hydrocarbon production from the Prairie du Silurian Sandstones Chien in central Michigan is from a massive unit of clean quartz sandstone with silica ce Cataract and Clinton Groups ment, approximately 5 per cent feldspar, with traces of pyrite, illite and chlorite (Fisher and The Clinton-Cataract Group is a sequence of Barratt, 1985). This unit represents the oldest Lower Silurian sandstones, shales and carbon and deepest stratigraphic interval tested in the ates. The Cataract Group comprises the Michigan Basin. There has been production Whirlpool Formation sandstones; the Mani from this unit in southern Michigan in the toulin Formation dolomites; the Cabot Head past At the present time, though, all of these Formation shales; and the Grimsby Formation wells have been abandoned. sandstones. The Cataract Group is overlain disconformably by the Thorold Formation Considerable controversy exists about the no sandstones and the Reynales Formation menclature and age of this unit and its corre dolostones, the two lowermost units of the lation to units at the periphery of the basin. Clinton Group (Figure 5c). Recently, it has also been referred to as the St. Peter, Jordan or Bruggers Formation (AAPG, a) Whirlpool Formation 1987). The sandstones of the Whirlpool Formation Trenton and Black River Groups consist of light grey, fine grained quartz with minor amounts of clay minerals and accessory The oldest stratigraphic units currently pro microcline feldspar (Fisher, 1954; Bolton, ducing hydrocarbons in southern Michigan 1957). The primary cement is silica with mi are carbonate rocks of the Middle Ordovician nor amounts of carbonate near the pinch out Trenton and Black River groups. These units edge of this unit (Sanford, 1969). consist of brown to grey mudstones and wack- estones with fossiliferous beds. Hydrocarbon b) Grimsby Formation production is confined to localized areas of dolomitization where dissolution has oc Sandstones and shales of the Grimsby Forma curred along linear structural features. These tion are composed of hematitic, very fine to dolomitized fracture zones are assumed to medium grained, greyish red and greyish provide the conduits for fluid flow since there white quartz sandstones interbedded with is negligible porosity and permeability in the greyish red shales (Fisher, 1954; Sanford, limestone country rock. 1969; Martini, 1971; Prendergast, 1982).

SILURIAN c) Thorold Formation Water samples are from the following units of The Grimsby Formation is disconformably Silurian age: 1) the sandstones of the Cataract overlain by the Thorold Formation, a thin and Clinton Groups, 2) the Guelph Formation greenish grey sandstone (Fisher, 1954; San and A l Carbonate in southwestern Ontario ford, 1969; Martini, 1971). The Thorold For-

11 * * -^ " DCVIJ A| CO -f { t © CLINTON

|.V.".V.V*V-V. C-XvXvXyX- THOROLD * GP. "^•l"t*t"X*X*X

i*.V.V.V.V.V.* •XvX'XvCvX

AvXv.v/w, ::?x?x::?S^ GRIMoBT **

A'XvCvvCvTv AWAVAVAt z /X'X'X'X'***" •VAWAVAV.' .;*v.;.v.v.v.v.; E LOWER JvCwXvXvX:uio^:i: CATARACT 9 GP. S

CABOT HEAD

r ^ * f s s s s MANITOULIN WHIRLPOOL *

Figure Se. Generalized stratigraphic succession, Niagara Peninsula and eastern Lake Erie, On tario (after Sanford, 1969). marion is probably derived from reworked tion were sampled for waters. The Brown Grimsby Formation sediments (Sanford, Niagaran, Gray Niagaran, and White Niaga 1969). ran litho-stratigraphic members of the Niaga ran Group in Michigan are the Twenty-five wells producing from Silurian lithostratigraphic and chronostratigraphic sandstones were sampled: four from the equivalents of the Guelph, Goat Island and Whirlpool Formation; ten from the Grimsby Gasport Formations in southwestern Ontario. Formation; and three from the Thorold For mation. The producing interval for seven Ten samples were obtained from the Niagaran wells had a combined Thorold/Grimsby pay Group and/or Salina Formation units in zone; one well had an open hole completion Michigan. Further subdivision of these units spanning the Thorold/Grimsby/Cabot Head was not possible as this information was not interval. available from the producer involved. Silurian Carbonates The Silurian carbonate samples from south Middle Silurian strata of the Guelph/Niagaran western Ontario were obtained from wells pinnacle and patch reefs, and the Upper Silu completed in either the Guelph Formation or rian A l Carbonate units of the Salina Forma the Salina Al Carbonate unit.

12 ©UNEDITED MANUSCRIPT© Guelph/Niagaran Pinnacle Reefs 1985, 1986, 1987). It is proposed that many of these reefs are located on structurally The Middle Silurian Guelph/Niagaran pinna higher parts of tilted fault blocks in southwest cle reefs possess relatively complex and vari ern Ontario (Sanford et al., 1985). If this is able stratigraphies as displayed in Figure 6 the case, then the related fractures may have (Sanford, 1969; Gill, 1973,1977; and Huh et played an important role in fluid migration. al., 1977). The reefs vary in vertical relief between 100 and 175 m (Sanford, 1969). Guelph Patch Reefs Both limestone and dolostone reefs have been discovered with the dolomitized reefs being Patch reefs from southwestern Ontario typi the most productive. The dolomitic pinnacle cally consist of sucrosic dolomite that is lo reefs generally grade from finely crystalline at cally bituminous and cherty (Sanford, 1969). the base to sucrosic near the top (Sanford, 1969). The reefs are closely related spatially Salina A1 Carbonate to the Upper Silurian AO, A l and A2 unit evaporitic carbonates, anhydrites and salts of The lower beds of the Salina A l Unit consist the Salina Formation (Figure 6). The diage of white and light gray anhydrite (A l netic history of northern Michigan pinnacle Evaporite) and are overlain by argillaceous reefs is well documented (Huh et al., 1977; limestones and dolostones (Al Carbonate) in Sears and Lucia, 1980; Cercone and Lehman, southwestern Ontario (Sanford, 1969).

B SALT

A-2 CARBONATE

A-2 (SALT) EVAPORITE GUELPH/ "RABBIT EARS BROWN ANHYDRITE NIAGARAN A-l CARBONATE A-1 REEF CARBONATE ANHYDRITE A-0 CARBONATE.

GOAT ISLAND X GRAY NIAGARAN Dolostone

GASPORT / WHITE NIAGARAN Dolostone

ROCHESTER SHALE

Figure 6. Schematic stratigraphy of a Middle Silurian pinnacle reef and encasing evaporite units (modified from Huh et al., 1977).

"UNEDITED MANUSCRIPT" 13 For purposes of simplicity, the Guelph/Niag- 1953; Sanford, 1968; Gardner, 1974; Uyeno aran and Salina Al Carbonate producing in et al., 1982; Dollar, 1985). Brown chert oc tervals will be referred to as Silurian curs throughout much of the Dundee Forma Carbonates. tion in southwestern Ontario (Sanford, 1968). The hydrocarbon traps in southwestern On Salina Unit Salts tario and Michigan occur in anticlinal struc tures where dolomitization of the micritic Salt deposition in the Michigan Basin is limestones has occurred. strongly controlled by the presence of the Middle Silurian barrier reef complex. Salt Devonian oil fields occur in fault-controlled occurrences in Ontario are almost exclusively anticlinal highs (Sanford, 1968; Sanford etal., confined to strata of Late Silurian age (San 1985). Selective dissolution of salts at depth ford, 1965). Salt beds are contained within along*these rejuvenated fractures has resulted the Salina A, B, D and F units. Brine samples in major collapse of the overlying Devonian. are from two salt mines, one located in Wind strata (Sanford et al., 1985). In central Michi sor (F Salt), the other at Goderich (A2 Salt). gan, the structural control is also provided by more deeply seated faults. Fault lineaments Salina A2 Salt mapped in Devonian reservoirs have also been used to locate fracture-related reservoirs in the In the Michigan Basin, the lower A2 Unit is Ordovician Prairie du Chien Group. dominated by salt that grades laterally to white and gray anhydrite on top of the pinnacle reefs Richfield Zone, Lucas Formation and is overlain by dolostones and minor lime stones (Sanford, 1965,1969). The Richfield Member of the Lucas Forma tion, Detroit River Group in central Michigan Salina F Salt consists mainly of interbedded anhydrites and The F Salt is zoned containing as many as five dolomicrites (Gardner, 1974; Matthews, salt layers separated-by dolomite and shale 1977). beds, with numerous anhydrite lenses and stringers (Sanford, 1965,1969). MISSISSIPPIAN

DEVONIAN Berea Sandstone

Dundee Formation The Berea sandstone in central Michigan is a very fine to fine grained feldspathic sandstone The Dundee in southwestern Ontario and with ankerite and silica cements (G. Gunn, Michigan is a fine to medium grained, micritic Pers. Comm.). Occasional interbedded shales limestone and dolomitic limestone (Best, occur throughout the formation.

14 ©UNEDITED MANUSCRIPT" STABLE ISOTOPES: OXYGEN AND HYDROGEN

INTRODUCTION STANDARD MEAN OCEAN WATER

Prior to the isotopic study by Clayton et al. The present-day stable isotopic composition (1966), most formation waters in marine sedi of ocean water is nearly constant, varying mentary basins were assumed to be original locally within narrow limits due to dilution waters trapped with the sediments at the time with fresh water or surface evaporation. The of sediment deposition (Chave, 1960; White, international reference standard for oxygen 1965; and others). However, the isotopic data and hydrogen isotopic compositions of water presented by Clayton et al. (1966) and other is Standard Mean Ocean Water or SMOW researchers have demonstrated that deep basin (Craig, 1961 a). Isotopic values presented are waters may also be derived from alternative reported as per mil (9to) deviations relative to sources, including the recharge of local mete the SMOW standard unless otherwise stated. oric waters that postdate sediment deposition. The present chapter briefly introduces some basic isotopic principles and the results of METEORIC WATER analyses on waters from the Michigan and northern Appalachian Basins. The possible The stable isotopic composition of oxygen histories of these waters are discussed in rela and hydrogen in present-day meteoric waters tionship to current models of diagenetic evo- exhibit systematic variations (Taylor, 1974; lution and mixing of deep-seated Fritz et al., 1987). Craig (1961b) has shown groundwaters in sedimentary basins. that the 818O and 8*H values in meteoric wa ters lie close to the Global Meteoric Water TERMINOLOGY Line (GMWL) described by the equation:

8 - NOTATION = 8^0+10

The results of isotopic determinations are ex pressed in terms of "8" values, which are The weighted mean annual isotopic composi calculated as follows: tion of present-day meteoric waters in south western Ontario and Michigan range from ~ R sample - R std ,.. -7.5 to -100xfo and -50 to -709to for oxygen and 8 = —— ^ - - 103 per mil deuterium respectively (Fritz et al., 1987). /?std ^

where R sample = (WH), (18O716O),..., and R std is the corresponding ratio in the stand RESULTS ard. By convention, the ratio (R) is written as the ratio of the heavy (rare) to h© ght (common) The isotopic values for the subsurface waters isotope. The sign of the value may be either from the present study are presented in Ap positive or negative depending on whether the pendix n and Figure 7. The isotopic results sample is enriched or depleted in the heavy for each of the individual producing units are isotope relative to the standard. discussed below.

"UNEDITED MANUSCRIPT" 15 10

-10- * PRESENT STUDY O CLAY TON tt 01.1966 O BREEN *t ol., 1985

-30

O -50 Local Meteoric ? Waters X -70

-90

-110- WATERS INDICATIVE OF COOLER CLIMATIC CONDITIONS

-130 -20 -15 -10 -5 S I8 (SMOW)

Figure 7. Oxygen and hydrogen isotopic compositions of all formation waters from the pre sent study. Data and respective basin lines for the Michigan Basin (Clayton et al., 1966) and

CAMBRIAN ORDOVICIAN

Results from the waters in Cambrian reser Prairie du Chien voirs of southwestern Ontario plot within a narrow range relatively close to the GMWL Owing to sample uncertainties, only one sam (Figure 8). These waters are considerably ple from the Prairie du Chien sandstone was enriched in 818O (values of -1.4 to -4.60x6o) and analyzed for 818O and 82R The 818O and &H o^H (values of -21 to -360yfo) relative to mod values for this sample were 1.607oo and SO^oo ern local meteoric waters. Cambrian produc respectively. tion in southwestern Ontario is confined to a linear trend with generally increasing 818O Trenton and-Black River Groups values from Oxford County in the northeast, to Essex County, in the southwest, along the The Trenton Group water samples were col erosional edge of these sediments. lected over a 200 kilometre section from Cal- houn County, Michigan at the southern rim of the Michigan Basin to Kent County, Ontario. Aside from one outlier, these waters plot in a relatively tight grouping with 818O ranges

16 ©UNEDITED MANUSCRIPT" from -1.3 to -S.Qo/oo and 52H from -20 to these waters range from -4.9 to -f 1.20^o and -340/00 (Figure 8). -49 to -40*^0 respectively.

SILURIAN Silurian Salts Waters from the A2 Salt are the most enriched Silurian Sandstones samples in 818O (approximately H-3) and have The isotopic composition of waters in the depleted 82H values around -5QP/QQ. These wa Silurian sandstones range from -1.7 to ters plot furthest away from the GMWL. The -4.50xfx) and -34 to -4607oo for 818O and &R F Salt waters have similar S2!! values, al respectively, with local variations within dif though they are depleted in 818O by approxi ferent areas of production in Norfolk County mately -80Xoo relative to the A2 salt and Lake Erie, Ontario. DEVONIAN Silurian Carbonates Dundee Formation Brines from the Silurian carbonates from the Guelph/Niagaran and Salina producing units Limited sampling of the Dundee Formation at have isotopic compositions that occur in a shallow depth at the periphery of the basin in linear trend with most variation in 18O isotopic southwestern Ontario and at depth in the cen ratios (Figure 8). The 818O and 62H values for tral portion of the basin reveals some interest-

O MISSISSIPPIAN -10 O DEVONIAN * SILURIAN SALT A SILURIAN CARBONATE 4- SILURIAN SANDSTONE -20 O ORDOVICIAN CARBONATE A ORDOVICIAN SANDSTONE x CAMBRIAN O Z 52 -30 a?

•F -4O

-50 l ' l /©A2 SALT

~- r SALT RICHFIELD -60 i—— -7.5 -5.0 -2.5 O 2J5 5.0

B "O S MOW)

Figure 8. Oxygen and hydrogen isotopic compositions of brines displaying individual groupings by reservoir age.

'UNEDITED MANUSCRIPT" 17 ing isotopic trends. Although the Dundee i) previous studies and ii) the individual stra water from Michigan plots in the same vicin tigraphic units of the present study. ity as most other brines, the samples from southwestern Ontario are distinctly different POSSIBLE INTERPRETATIONS isotopically. The waters from southwestern Ontario have 8^ and 818O signatures that are Clayton et al. (1966) were the first investiga depleted by approximately TQO/oo and 1307oo tors to attempt a comprehensive study of the respectively, relative to the more concentrated isotopic composition of formation waters in waters found deeper in the basin. The Dundee sedimentary basins. They discovered that the samples from southwestern Ontario plot along subsurface waters in the Michigan Basin had the GMWL and are depleted by as much as isotopic signatures which were different from -n.4%0 in 818O and -1200/00 for 8^ (Figure seawater and could be extrapolated back to the 7). The one sample analyzed from the central local meteoric intercept on the global meteoric basin had a 818O value of -0.907oo, and a value water line (Figure 9a). As a result, they con of-3407oo for 82H. cluded that all of the primary or connate for mation waters had been flushed from the One additional Devonian sample was col system and replaced by meteoric water. De lected from the underlying Richfield Zone of viation from the intercept was attributed to the Detroit River Group in central Michigan isotopic exchange and fractionation during from the same field as the Dundee water. The burial. Richfield sample was enriched in 818O and The deviation of these sedimentary basin depleted in o^H relative to the Dundee Forma water 818O and S2!! values from the meteoric tion (0.20/bo and -550/00 respectively). water intercept requires a mechanism that causes enrichment in both isotopic ratios rela MISSISSIPPIAN tive to meteoric water. Most sedimentary ba display large enrichments in 818O The samples from the Mississippian Berea sin brines sandstone follow a trend that parallels the and relatively small enrichments in o^H rela local meteoric water intercept (Figure 8). The tive to local meteoric water. The oxygen en isotopic values range from 0.3 to -3.90/00 for richment of formation waters is attributed to 18O and from -24 to -52^oo for 2H. isotopic exchange reactions between the wa ters and associated carbonate minerals (Clay ton et al. 1966; Hitchon andFriedman, 1969). DISCUSSION Deuterium exchange between water and hy drogen-bearing compounds is minimized by A number of mechanisms have been proposed the overwhelming mass of formation water to account for the isotopic compositions of relative to hydrogen-bearing compounds. sedimentary basin waters. These processes The enrichment of deuterium is attributed to include: 1) the evaporation of seawater or membrane filtration for sedimentary basins meteoric water, 2) mixing of different waters with significant shale horizons (Graf et al., (ie., meteoric water with connate waters), 3) 1965; and Hitchon andFriedman, 1969). water rock interaction, 4) membrane filtration, and 5) the release of diagenetic waters during Although Clayton et al. (1966) and Hitchon burial diagenesis (eg., dehydration of gyp and Friedman (1969) proposed similar sum). Each will be addressed as it applies to mechanisms for isotopic enrichment, their

18 'UNEDITED MANUSCRIPT" Clayton ct ol. (1966)

Holscr (1979)

-iqtf 8 *0 *. (SHOW)

Hitchon and Fricdman (1969)

-Mtf

8 **0 *. (SNOW)

ft O fe(SMOW)

Figure 9. Oxygen and hydrogen isotopic interpretations by: a) Clayton et al. (1966); b) Hitchon and Friedman (1969); and c) Hosier (1979). conclusions as to the origin and isotopic evo topic composition may be derived by an lution of sedimentary basin waters were quite evaporative process similar to the model pre different. Hitchon and Friedman (1969) as sented in Figure 9c. sumed sea water to be the original water com position. The sea water isotopic composition During evaporation, water becomes progres was later modified by exchange with associ sively more enriched in 818O and 8^. The ated carbonate minerals and membrane filtra slope of the path taken on a 818O versus S^H tion during burial diagenesis, resulting in diagram is dependent mainly on the humidity isotopic enrichment of both components (Fig and other local climatic variables (Craig and ure 9b). Subsequent infiltration and mixing Gordon, 1965; Lloyd, 1966). Arrows A and of isotopically depleted meteoric water with B on Figure 10 indicate the trajectories for the diagenetically modified sea water was re high and low humidities respectively. Enrich sponsible for depletions in isotopic abun ment of both deuterium and 18O relative to dances of the sea water derived end member. SMOW during evaporation does not continue Positioning of the waters, isotopic composi indefinitely. Once gypsum or anhydrite pre tion on the 818O versus 82H plot was a function cipitate, isotopic enrichment ceases and the of proportions of these two end member com water becomes progressively more depleted positions. due to the removal of the heavier isotopes into Recently, Knauth and Beeunas (1986) have precipitated mineral phases (Holser, 1979; proposed an alternative process to account for Pierre et al., 1984). The shape and extent of the isotopic composition of sedimentary basin the hooked trajectory is probably controlled waters. They have shown that the stable iso by factors similar to those that affected the slope of the line during initial evaporation

'UNEDITED MANUSCRIPT" 19 (Knauth and Beeunas, 1986). This model for is much more complicated than previously isotopic evolution is based on limited field and thought and may represent several inde experimental data and may not be readily pendent hydrologic systems indicated by the applicable to complex natural systems. extreme dispersion of some waters from the line in Figure 7. Waters from the Cambrian The implications of this work on future stable sandstones and Ordovician carbonates, for ex isotopic interpretations may prove to be quite ample, are significantly enriched in 82H rela revolutionary. The negative isotopic values tive to the overlying units. These waters may from previous studies are used to rule out an have a meteoric component that was enriched evaporative seawater origin (Clayton et al., relative to present-day meteoric water. 1966; Land and Prezbindowski, 1981,1985). Negative o^H and 818O values, using the Alternatively, this enrichment may also be evaporation model proposed by Knauth and explained by the membrane filtration model Beeunas (1986), no longer need be interpreted proposed by Bredehoeft et al. (1963). The as being the product of meteoric water influ waters were forced from the shale-free Cam ence since similar results may simply be the brian and Ordovician aquifers up through the result of extreme evaporation of seawater fol extensive overlying Ordovician shales. As lowing hooked trajectories. these waters migrated through the semi-per meable membranes, the heavy isotope of hy PRESENT STUDY drogen was preferentially retarded, leaving the residual pore water in the Cambrian and All formation waters from this study plot be Ordovician reservoirs isotopically enriched. low and to the right of the GMWL which is typical for sedimentary basin brines (Figure ISOTOPIC EVOLUTION OF 7). Also shown are comparable data from INDIVIDUAL UNITS other studies: the Michigan Basin (Clayton et al., 1966) and three sandstone producing in Most brines from the present study plot within tervals from the Appalachian Basin in Ohio a narrow range of isotopic composition for the (Breen et al., 1985). These studies all have individual stratigraphic units sampled (Figure negative o^H values and positive to negative 10). The isotopic difference between the wa 818O values relative to SMOW. ters of the units sampled may indicate differ ent origins, mixing, or different isotopic Traditionally, a meteoric water component fractionation processes. has been advocated to account for such distri butions (Clayton et al., 1966; Hitchon et al., The Cambrian and Ordovician brines have 1969). The wells sampled by Clayton et al. identical deuterium ranges (Figure 10); how (1966) are extremely biased toward younger ever, most Ordovician waters are enriched in stratigraphic units with only five of the 518O. The preferential enrichment of 818O twenty-four samples from pre- Devonian res may be the result of isotopic exchange be ervoirs. The present study considers more tween these waters and the carbonate reservoir samples, and a larger proportion from deeper rocks. Although this oxygen enrichment is horizons than the earlier study. The isotopic generally the case, in Essex County where data in this study seriously questions the va Cambrian and Ordovician producing areas lidity of the Michigan Basin line proposed by overlap, they have virtually the same 818O Clayton et al. (1966). Obviously the system signatures. The next nearest Cambrian well

20 'UNEDITED MANUSCRIPT" O MISSISSIPPIAN 4O Q DEVONIAN * SILURIAN SALT EVAPORATING A SILURIAN CARBONATE SEA WATER -l- SILURIAN SANDSTONE 20 O ORDOVICIAN CARBONATE A ORDOVICIAN SANDSTONE x CAMBRIAN ~ O O W -20

* i? -4O z M tfO

-eo

-too -12.5 -7.5 -2.5 2.5 7.5 12.5

S I8 0 7o. (SMOW)

Figure 10. Trajectories for sea water undergoing evaporation superimposed over data from the present study. Curve A represents initial evaporation under relatively humid conditions; curve B is for arid conditions. Curve C is Holser©s (1979) estimate of evaporating sea water through a concentration of l OX. The dashed curve extrapolation to 45X is based on incomplete data. Curve D is given by Pieme et al. (1984). The isotopic composition of hydration water in gypsum precipitated on any point on evaporation trajectories C and D is given by curves C© and D© re spectively. The solid parts of curves C© and D© correspond to gypsum precipitated in the gyp sum facies during the evaporation of sea water 3-1IX). Halite facies corresponds to ^11-65X. Figure and caption are modified from Knauth and Beeunas (1986). also plots in the region of the Ordovician with localized values possibly reflects the water isotopic composition, although it does slight differences in temperature, individual have a slightly lower 818O signature. It is not water sources or exchange reactions with en known whether these similarities in isotopic closing carbonate reservoir rocks. Since de compositions are local features or large scale tailed sampling for this study focused on phenomena since there are no other areas in Ordovician aquifers, these regional and local which there is currently production from both phenomena may also occur in some of the Cambrian and Ordovician reservoirs. other units; although they were not always detected. Within the tight cluster of Ordovician sam Two samples from the Albion-Scipio Trend ples, there are local groupings by field and probably represent casing leaks as they plot on location. This regional isotopic signature

'UNEDITED MANUSCRIPT' 21 mixing lines between waters from the Tren concentrated brine with an isotopically de ton-Black River Groups and the overlying pleted water. Niagaran Group (Figure 8). The A2 Salt, F Salt and Richfield Zone are Waters from the Silurian and Mississippian lithologically unique in that salt and anhydrite sandstones exhibit a general dilution in 818O make up a sizable portion of these units. The and 82R This dilution effect is well devel origin of anhydrites in evaporite sequences is oped on the 818O versus TDS plot in Figure unresolved; some workers consider it to be a 11. The most concentrated Berea sandstone primary phase while others contend that it waters have the highest 818O and 82H values forms as gypsum dehydrates during burial. (O^oo and -23^oo respectively) with dilute wa Gypsum is shown in lab experiments to be the ters displaying isotopic depletion. There is a CaSO4 phase which is thermodynamically direct correlation between TDS and isotopic stable at temperatures 20C (Hardie, 1967); it composition indicating that this dilution may is demonstrated however, that anhydrite could be a modern artifact resulting from mixing a have been a primary precipitate controlled by kinetic factors (Cody and Hull, 1980). If the

o

C/) -l l l /GUELPH/ -P -S NIAGARAN

IO +T*/ "*i v x \ \ / cV^ T*" \* ^ \ ' Af f NA\X X X^ \ © -5 f CMIl|RlAN X x^/

F SALT

-7 l_____l 100000 2OOOOO 300000 40OOOO TDS (rog/l)

Figure 11. Oxygen isotope composition versus TDS concentration.

22 'UNEDITED MANUSCRIPT' anhydrite in these evaporative units had a positioning between the different water types gypsum precursor, then a diagenetic water is probably^a function of local lithologic vari component could have been added to the sys ations, and/or mixtures between concentrated tem by the conversion of primary gypsum to brines and diagenetic waters expelled during anhydrite during burial diagenesis. The gypsum dehydration. There are two waters water of hydration in gypsum has been found from this unit that show considerable deple to be enriched in 18O by approximately 4 per tion in 818O relative to the above mentioned mil and depleted in -^ by about 20 per mil waters. relative to the parent water (Sofer, 1978). This combination of enrichment and depletion The deep basin Dundee sample from central was evident in both the A2 Salt and Richfield Michigan plots near the centre of values on the Zone samples as these samples show an en 818O versus o^H diagram around O^oo and richment in 18O and are depleted in 2H relative -30^oo (Figure 7). The Dundee waters from to most other concentrated brines. the shallow subsurface in southwestern On tario probably represent mixtures of original Although the F Unit salt is also spatially re concentrated formation brines (similar to the lated to anhydrites, these waters bear no re sample mentioned above) and waters re semblance to gypsum hydration waters charged under cooler climatic conditions, pos isotopically. These waters have most likely sibly at the end of the last period of glaciation. migrated into this formation from an adjacent The possibility that these waters have been carbonate unit since its isotopic signature is contaminated by interconnection between the more characteristic of brines from these li- overlying Pleistocene aquifer (depleted iso thologies. topic values; Desaulniers et al, 1981) and the underlying formation is a reality that must be The Silurian carbonate waters from the considered (see sampling section). The gla Guelph/Niagaran and A l Carbonate reser cial associated waters may not have naturally voirs generally lie in an area between recharged into the underlying strata as pre evaporite associated waters, and carbonate viously reported in Clayton et al. (1966) but and clastic reservoir waters in Figure 8. This may result from casing leaks.

'UNEDITED MANUSCRIPT' 23 WATER CHEMISTRY

CHEMICAL CHARACTERISTICS Several mechanisms have been proposed to account for high salinities and chloride con The formation waters analyzed in this study centrations of many sedimentary basins. Ele vary significantly in salinity and chemical vated salinities are presently believed to result composition between different stratigraphic from one or more of the following mecha units. However, waters from the same stratig nisms: (i) infiltration and burial of subaerially raphic interval generally have similar chemi evaporated waters (Carpenter, 1978), (ii) the cal compositions across the study area. The subsurface dissolution of halite (Land and chemical analyses of all waters from each Prezbindowski, 1981), and (iii) membrane stratigraphic horizon are listed in Appendix IL filtration (Graf, 1982). Subsequent modifica The principal ions contained in these waters tion of waters produced by these processes are Ca, Na and CI; although, some variation may result from mixing of different waters in the Ca/Na ratios does exist between and (eg., connate brines diluted by the influx of within formations (Table 3). fresh meteoric waters) or by interaction be tween the pore fluids and enclosing reservoir rocks. Almost all groundwaters are brines as they contain between 140 and 391 g/l IDS (Table The CI concentrations for most formations do 3); the only major exception being the dilute not exhibit any general tendency to increase saline and brackish waters from the Dundee with sample depth (Figure 12). The maxi Formation in southwestern Ontario. mum observed salinities of these waters level Table 3: Water classification and dominant ions.

Formation Principal Ions Classification IDS (g/l) (20 g/l)

Berea CaNaCl Brine 230-312 Dundee (Ont.) CaNaCl-NaCl Brackish - Saline 3-15 Dundee (MI) NaCaCl Brine 292 Richfield CaNaCl Brine 282 F Salt NaCl Brine 304 - 322 A2Salt CaNaCl Brine 340 Al CaNaCl-NaCaCl Brine 198 - 391 Carbonate/Guelph/Niagaran

Thorold/Grimsby NaCaCl-CaNaCl Brine 191- 325 Whirlpool Trenton/Black River NaCaCl Brine 140- 239 Prairie du Chien CaNaCl Brine 325- 391 Cambrian CaNaCl Brine 174- 338

'UNEDITED MANUSCRIPT" 25 CI (mg/i) 100000 200000

0 MMtMIPMAN

A XUNUAN CMtONTC * MJMWIf MMOflTONC O omawcMM CMMMATI * MOOMCUH tAMMTOMC

-500-

0. 4) Q \ \ l -1000 ^ ^\ \ . -^

' /

-1500L

Figure 12. CI concentration versus sample depth. off and never exceed values greater than 400 mentary basin hydrogeochemical systems, g/L Several significant reversals occur in sa chloride is the dominant anion. Chloride be linity and chloride concentration within the haves in a conservative manner, entering into study area. The most pronounced variations precipitation/dissolution reactions at high sa are: the dilute waters of the Dundee Formation linities where halite precipitation occurs. For (near recharge areas at the basin periphery), these reasons, chloride has been chosen both and the very concentrated waters of the as the comparative species to define the rela Guelph/Niagaran units (spatially related to tive abundance of other chemical constituents evaporites). and as a normalizing factor to interpret possi ble sources of saline constituents. Chloride correlation plots allow one to determine how reactions have affected the concentration of DISCUSSION dissolved species in these waters. Most spe cies follow trends indicating that little or no The chemical composition of water within the reaction occurs between CI and the dissolved individual units is modified by rock water aqueous species. Reactions produce concen interaction, halite dissolution, mixing of wa trations that plot either above (species added ters, and membrane filtration. Several of to the solution) or below the general trends these processes can be identified with the aid (species precipitated from solution). Dilution of chloride correlation plots. In most sedi

26 "UNEDITED MANUSCRIPT" of these chemical parameters by the input of in waters associated with the Upper Silurian F fresher waters may also be detected. Unit salt. It is frequently conserved in aque ous systems in which it is associated with Nesbitt (1985) has produced plots of various chloride, until halite saturation is reached and elemental ratios over CI versus CI concentra precipitation occurs. tion. This allowed him to assess any chemical effects the above mentioned processes had on For most of the units studied, a constant de formation water composition in the Illinois crease in Na/Cl ratios with increasing CI con Basin. Similar plots have been constructed centration is apparent (Figure 13a). This plot for selected elements in sedimentary basin has been selected to examine the role that waters from southwestern Ontario and Michi halite dissolution and mixing waters of differ gan. ing origins played in the formation of these concentrated brines. All of the Na/Cl ratios ALKALI METALS (NA, K) from the present study are much lower than the seawater value (0.57). The absolute CI Sodium is the most abundant member of the concentrations in the brines are considerably alkali metal group in the waters studied and is higher (up to 260 000 mg/1) than the seawater present in concentrations up to 100 000 mg/1 concentration of 19 000 mg/1 (Krauskopf,

sw U.D * . HALITE DISSOLUTION

i A . 'l \ f ^ 0.4 \ o " xv"*fc N * X s*\'** t** X* *0 0.3 DILUTION x ** **f 4*0^ \* O

D .* . x x'-'-v/^'x ^0.2 \ *"^V" -^

0 MISSISSIPPIAN X 0 DEVONIAN X * * SILURIAN SALT O * A \ A SILURIAN CARBONTE - * 0.1 * SILURIAN SANDSTONE * * * 0 ORDOVICIAN CARBONATE t ORDOVICIAN SANDSTONE X CAMBRIAN

0.0 ( 100000 200000 (mg/l)

Figure 13a. Na/Cl ratios of formation waters as a function of their chloride content (after Nes bitt, 1985).

'UNEDITED MANUSCRIPT" 27 1979). Calculations of halite dissolution respect to halite. If halite were to be dis chemistry show that equal molar proportions solved,©then the Na/Cl ratio would increase. of Na and CI are released to solution (Na/Cl = 0.65 on g/g basis; Nesbitt, 1985). Based on this information, the brines from the Potassium/chloride versus chloride plots for Gualph/Niagaran, Salina F Unit salt and Rich most sandstone units have constant K/C1 ra field Zone that plot above the generally de tios (Figure 13b). However, K concentrations creasing trend are presumed to be the product for waters from the Guelph/Niagaran and A l of halite dissolution. Carbonate units display a trend towards in creasing chemical ratios with increasing chlo ride concentration. These waters may The Silurian sandstone samples from eastern represent bittern fluids, rich in potassium, as Lake Erie and one Cambrian water sample they are spatially related to the Salina Forma have constant Na/Cl ratios and variable CI tion evaporite units. concentrations. These waters plot to the left of the trend indicating dilution must have occurred. Addition of fresh waters to the sys The highest K concentrations were encoun tem serves to reduce the absolute CI concen tered in samples from the Ordovician Prairie tration which does not alter the Na/Cl ratio du Chien sandstones. Several factors, related provided that the waters remain saturated with to the extreme depths from which these brines

0.06

O MISSISSIPPIAN O DEVONIAN 4P SILURIAN SALT A SILURIAN CARBONIC * SILURIAN SANDSTONE O ORDOVICIAN CARBONATE * ORDOVICIAN SANDSTONE 0.04 X CAMBRIAN

o

0.02 sw

0.00 100000 200000 CI (mg/l)

Figure 13b. K/C1 ratios of formation waters as a function of their chloride content.

28 'UNEDITED MANUSCRIPT' are produced, may control their chemical na ture. It is possible that these waters may have a concentrated evapoiitic component. How The correlation plot for Ca/Cl versus chloride, ever, these fluids may also be the product of shown in Figure 13c, displays a steady linear water vapour condensation (see sampling sec increase for most stratigraphic units. The con tion) or drilling fluid contamination. Much of centration of Ca increases with increasing this conjecture is based on the fact that all of chloride concentration. The only samples not the other sandstone units have much lower K to follow this trend are from the Upper Silu concentrations. The relatively low K concen rian F Unit salt and the Lower Silurian sand trations in the Cambrian, Silurian and Missis stones under eastern Lake Erie. The F Salt sippian sandstone units can be attributed to a waters are dominated by Na and as stated number of factors. Potassium feldspars, a earlier are believed to be the product of halite possible source of K in these rocks are, for dissolution. The waters from the Silurian example, resistant to leaching by water at sandstone and other units that plotted below lower temperatures (Collins, 1975). Sec the Na/Cl trend in Figure 13a (product of ondly, absorption by clay minerals also limits dilution?) plot above the Ca/Cl trend line.. the concentration of K in solution.

The Mg/Cl versus CI relationship in Figure 13d suggests that most stratigraphic units

0.4 O MISSISSIPPIAN O DEVONIAN DILUTION 4? SILURIAN SALT A SILURIAN CAR80NTE * SILURIAN SANDSTONE ^ . O ORDOVICIAN CARBONATE * A 0.3 4 ORDOVICIAN SANDSTONE X CAMBRIAN

* O O O

HALITE 0.1 - DISSOLUTION

0.0 100000 200000 CI (mg/l)

Figure 13c. Ca/Cl ratios of formation waters as a function of their chloride content (after Nes bitt, 1985).

'UNEDITED MANUSCRIPT" 29 have relatively constant Mg/Cl ratios with brines, since these brines also have corre values between 0.03 and 0.05. The concen spondingly high K and Ca concentrations. tration of Mg in these waters is probably con trolled by dolomitization processes. Water Strontium, a minor element in these waters samples from strata that are spatially related compared to Ca and Mg, is present in concen to salt either have ratios that are higher (A2 trations up to 3 000 mg/L The chloride corre Salt, A l Carbonate, Guelph/Niagaran) or lation plot in Figure 13e suggests a general lower (F Salt) than the ratios for the other increase in Sr/Cl ratios for most samples. The units. The lower ratios for the F Salt indicate Guelph/Niagaran waters follow a steeply that these waters are the product of halite sloping trend toward higher Sr/Cl ratios with dissolution and are not residual brines. As increasing chloride concentration. Although halite is dissolved, CI is released to solution Sr resembles Ca chemically, there is no direct and the ratio of Mg/Cl is reduced On the relationship between Ca/Cl and Sr/Cl ratios other hand, the concentrated samples from the and chloride concentration. Two reactions A2 Salt, A l Carbonate and Guelph/Niagaran contributing Sr to these waters are (i) the strata with elevated Mg/Cl ratios were prob release of Sr during alteration of aragonite to ably derived from very concentrated residual calcite and (ii) dolomitization. During dolo-

0.08

sw

0.06

4 , \ ** m * O * f,:'v ?..; 7:.. -

O MISSISSIPPIAN O DEVONIAN 0.02 - V SILURIAN SALT A SILURIAN CARBONTE * SILURIAN SANDSTONE O ORDOVICIAN CARBONATE 4 ORDOVICIAN SANDSTONE X CAMBRIAN 0.00 100 200000 CI (mg/l)

Figure 13d Mg/Cl ratios of formation waters as a function of their chloride content (after Nes bitt, 1985).

30 'UNEDITED MANUSCRIPT" 0.0125 O MISSISSIPPIAN O DEVONIAN V SILURIAN SALT A SILURIAN CAR80NTE 0.0100 * SILURIAN SANDSTONE O ORDOVICIAN CARBONATE 9 ORDOVICIAN SANDSTONE X CAMBRIAN

0.0075 O

C/) 0.0050

A A 4 0.0025 x * * . sw 0.0000 100000 200000 CI (mg/l)

Figure 13e. Sr/Cl ratios of formation waters as a function of their chloride content.

mitization, Sr is replaced by Mg in the solid 1975; Carpenter, 1978; Holser, 1979). Bro phase, releasing Sr to solution. mide, a minor component of these waters, is selected since it is generally considered to be SULPHATE non-reactive. It is rapidly concentrated during seawater evaporation and halite precipitation. The data for sulphate shows a distinctly dif The precipitating salts have lower Br concen ferent trend than any of the other species trations than the parent solutions from which relative to CI (Figure 13f). Clearly, sulphate they precipitated. It is for these reasons that concentration decreases with increasing chlo Br-rich brines are often interpreted to repre ride. The concentration of SO4 in these waters sent connate waters (Carpenter, 1979; Stoes- is controlled by the abundance of Ca, Sr and sell and Moore, 1985). Conversely, brines Ba as well as bacterial activity (Collins, 1975). depleted in Br are believed to result from the dissolution of halite (Rittenhouse, 1967; Hol ser, 1979). Chloride is used for comparison HALOGENS (CI, Br) as it is the least reactive major ion in deep Relationships between bromide and chloride subsurface groundwater systems. The bro concentrations in subsurface waters are used mide/chloride ratios in the present study gen to determine the origin of water salinity erally increase with increasing chloride (White, 1965; Rittenhouse, 1967; Collins, concentration indicating the conservative na-

VNEDITED MANUSCRIPT" 31 0.010 O MISSISSIPPIAN O DEVONIAN V SILURIAN SALT A SILURIAN CARBONTE 0.008 * SILURIAN SANDSTONE O ORDOVICIAN CARBONATE t ORDOVICIAN SANDSTONE x CAMBRIAN

0.006 O

4 A en o.oo4 V*. J

0.002 * 4

0.000 200000 300000 CI (mg/l)

Figure 13f. SCVC1 ratios of formation waters as a function of their chloride content.

0.015 O MISSISSIPPIAN O OCVONIAN * SILURIAN SALT A SILURIAN CAR80NTE * SILURIAN SANDSTONE C ORDOVICIAN CARBONATE 4 ORDOVICIAN SANDSTONE K CAMBRIAN 0.010 * t * * 4 ** 1 4*4

A ^L. A * A O t \ O *4 .*-" f 11* A©4 A B* * * mL. * A ^ 4.^ 4 *A A 0.005

0.000 100000 200000 CI (mg/l)

Figure 13g. Br/Cl ratios of formation waters as a function of their chloride content.

32 'UNEDITED MANUSCRIPT' ture of these species (Figure 13g). The low The HCOs term has been dropped from the Br/Cl ratios for the F Unit salt are charac formula for these calculations due to its ex teristic of waters that have a dissolved halite tremely low concentrations in the waters stud component (Rittenhouse, 1967). ied.

CARPENTER©S SEAWATER The relationship that exists between MC12 and EVOLUTION MODEL Br for samples from this study are illustrated in Figure 14. All brines lie above the line Reconstructions of chemical evolutionary indicating that they are enriched in MC12 or paths of many highly saline formation waters depleted in Br relative to evaporated seawater. are often attempted using the methodology It may be possible to determine whether this presented by Carpenter (1978) to predict the deviation is due to a relative gain or loss of chemical composition of brines derived from some constituents, since trends of all other evaporating sea water. The model also has the major constituents are known (Carpenter, ability to quantitatively predict changes in 1979). brine composition resulting from water rock interaction with a variety of common sedi When a solution containing a variety of dif mentary basin minerals. As rock water inter ferent ions is concentrated by evaporation, the action is a possible major control for the brines ratio of the particular ions with respect to each studied, a detailed investigation of this model other is constant unless mineral precipitation has been performed. or rock water interaction is occurring. The rise in ionic concentration relative to bromide During the evaporation of sea water, K, Rb, is constant with a slope equal to l until pre Li, and Br remain in solution until K salts cipitation or some process other than the re begin to precipitate (Zherebtsova and Volk- moval of water occurs. Concentration trends ova, 1966). Bromide is the most conservative of ions in sea water relative to bromide during element from this group that does not actively evaporation in a non-reactive environment are participate in diagenetic reactions, making it shown in Figure 15. Changes in slope that the obvious element for tracing the evapora occur with increasing concentration relate to tion of sea water. Bromide has also been the precipitation of minerals containing the utilized in an earlier study on possible origins specific ion in question. of oil field brines (Rittenhouse, 1967). Figure 16 illustrates the relationship between The concentrations of divalent ions electri chloride and bromide concentrations in brines cally balanced by chloride (MC12), like Br, from southwestern Ontario and Michigan. may also be very useful in attempts to recon The data points lie on a trend line which struct the chemical evolutionary history of extends from lower chloride concentrations brines, provided that carnallite than found in evaporated seawater containing (KMgCl3*H2O) precipitation has not occurred the same amount of bromide, to waters that are (Carpenter, 1978). Since the Br and MC12 enriched in chloride relative to bromide. The contents are often very similar, these two pa brines from the Upper Silurian A2 Salt, the rameters can be used interchangeably. The Middle Silurian Guelph/Niagaran carbonates MCb component of seawater is calculated and the Prairie du Chien sandstone have using the following equation: higher chloride and bromide concentrations than any of the other formations sampled. MC12 = Ca * Mg 4- Sr - SO4 - 0.5 (HCO3) meq/1 These samples plot above the sea water evapo-

VNEDITED MANUSCRIPT' 33 MISSISSIPPIAN DEVONIAN SILURIAN SALT SILURIAN CARlOMTE SILURIAN SANDSTONE ORDOVICIAN CARBONATE ORDOVICIAN SANDSTONE CAMIMAN

2.4 2.4 2.6 2.8 3.0 3.2 3.4 3.6 3.8 Log Br (mg/l ) Figure 14. Concentrations of MCk relative to Br. The line shows the concentration trend for

5.5

5.0

2.5

2.0 1.5 2.0 2.S 3.0 3.5 4.0 Log Brlmg/l) Figure 15. Concentration trends of ions in sea water relative to Br during evaporation and pre cipitation (after Carpenter, 1978).

34 'UNEDITED MANUSCRIPT' ration curve well past halite saturation. The mide and chloride concentrations. The pro data points for the Upper Cambrian and Mis portion" of less saline water in these brine sissippian Berea sandstone lie on the trend line mixtures is indicated by the depletion relative produced by the evaporation of sea water. to the horizontal portion of the seawater The Devonian samples from Michigan from evaporation curve. In the present study, it is the Dundee Formation and the Richfield Zone not possible to determine the compositions of the Lucas Formation also plot along the sea and proportions of various waters that have water evaporation line. This positioning on combined to form these solutions due to the the line suggests that components of these complex nature of the ancient hydrologic re brines could be genetically related to evapo gimes previously alluded to in the isotopic rated sea water. section. Brines from the Middle Ordovician Trenton and Black River Group carbonates and the The dilute Devonian samples from southwest Lower Silurian sandstones plot along trend ern Ontario have chloride and bromide con lines from relatively low bromide and chloride centrations that are less than sea water. concentrations to values similar to evaporated Therefore, a sea water evaporative model for sea water. This relationship is shown in Fig much of this water can be ruled out. These ure 16 to result from mixing of halite saturated samples have not been plotted on the dia brines with fresh water and sea water. The grams. mixing of halite saturated brines with less saline waters causes water compositions to The samples collected from the F Salt are rich move along mixing lines toward lower bro in chloride, though depleted in bromide. This

5.5

5.4 HALITE DISSOLUTION ———c^r^"P* 4I*V 5.2 f ** .©,V~** * *** r 5.1 f * V* * n*f f t? * o **MISSISSIPPIAN O 4-w 1 DEVONIAN *N SILURIAN SALT 5.0 H SILURIAN CARBONTE en • f SILURIAN SANDSTONE 4.9- DILUTION ORDOVICIAN CARBON*! ORDOVICIAN SANDSTOA CAMBRIAN 4.8 2.4 2.6 2.8 3.0 3.2 3.4 3.6 Log Br (mg/l)

Figure 16. Concentration trend of CI in sea water relative to Br during evaporation and precipita tion of halite and carnallite (after Carpenter, 1978).

'UNEDITED MANUSCRIPT" 35 * MISSISSIPPIAN a ocvONiAN * SILURIAN SALT A SILURIAN CAMtONTC 5.0 -i * SILURIAN SANDSTONE C ORDOVICIAN CARSONAlt ORDOVICIAN SANDSTONE CAMBRIAN

4.6-

4 A

4.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6 Log Br (mg/l) Figure 17. Concentration trend of Na in sea water relative to Br during evaporation and precipi tation of halite (after Carpenter, 1978). positioning above the sea water evaporation waters that are preferentially enriched in chlo line below halite saturation in Figure 16 is ride relative to bromide similar to the F Salt attributed to the dissolution of halite as noted (as discussed earlier). earlier (Carpenter, 1978). The basic assump tion here being that halite contains only a Other comparisons based on the Br data reveal small proportion of Br relative to chloride in that most waters are depleted in Na, K, Mg and its crystal structure. Therefore, the dissolu S 04 while being enriched in Ca relative to tion of halite in sea water would produce seawater (Figures 17-20).

36 'UNEDITED MANUSCRIPT" SJQ -i

1.0 1.5 2.0 3L5 3.0 3.5 4.0 Log Br (mg/l)

Figure 18. Concentration trend of Ca and S 64 in sea water relative to Br during evaporation and precipitation of calcium sulphate (after Carpenter, 1978).

4.4 - Q KVMMAN V SILURIAN **LT A WumUW CAMONTC * WLMMAM CAMOSTOME

4.2 - 9 OftOOVKIAN MMMTOHC K CAMtHIAM

4.0 -

3.8-

3.6 - •••/V*

3.4 2.4 2.6 2.8 3.0 3.2 3.4 3.6 Log Br (mg/l)

Figure 19. Concentration trend of Mg in sea water relative to Br during evaporation and precipi tation of magnesium sulphate and carnallite (after Carpenter, 1978).

'UNEDITED MANUSCRIPT' 37 4.5 n

O MISSISSIPPIAN O OCVONIAN tt SILURIAN SALT 4.3 - A SILURIAN CARBONTC * SILURIAN SANDSTONE O ORDOVICIAN CARBONATE 9 ORDOVICIAN SANDSTONE 4.1 - le CAMBRIAN

3.9 -

3.1 H

* * ****0 2.9 - -i-*T . *o o

2.7-

2.5 -l l l l I f l p l j l l 2.4 2.6 2.8 3.0 3.2 3.4 3.6 Log Br (mg/I)

Figure 20. Concentration trend of K in sea water relative to Br during evaporation and precipita tion of carnallite (after Carpenter, 1978).

38 'UNEDITED MANUSCRIPT" STRONTIUM ISOTOPES

INTRODUCTION brian to the Mississippian with several oscil lations in the interim. If Michigan Basin As part of a hydrogeochemical study of brines are the same age as their reservoir groundwater behaviour, Sr isotopes in con rocks, then most have ^Sr/^Sr values that are junction with chemical analyses and stable greater than seawater for the respective time isotopes are used here to assess the extent of period in question. The only exceptions to water rock interaction. This chapter reports this are the Upper Silurian Salina Formation the results of water analyses from several waters, four waters from the Middle Silurian stratigraphic units within the Michigan Basin Guelph/Niagaran reefs, and one sample from in southwestern Ontario, Canada and southern each of the Middle Ordovician Trenton Group Michigan, U.S.A., as well as brines from some and Mississippian Berea Formation. of the same rock units that are part of the Appalachian Basin in southwestern Ontario. Based on the above assumption, the elevated Some aspects of this work have already been ratios imply that there has been some degree discussed in a previous article (McNutt et al., of water rock interaction in situ. The radio 1987). genic Sr would be derived from Rb-bearing phases (mica, clay minerals, and K-feldspar) Mineral phases and host rock material have old enough for 87Rb decay to have produced also been analyzed to measure the extent of measurable amounts of ^Sr, resulting in ratios isotopic equilibration between water and rock. well above their initial seawater value.

BRINE SIGNATURE AND If the waters are not the same age as their SEAWATER SR present reservoirs, then the interpretation be comes much more complicated. The Middle The ^Sr/^Sr results are listed in Appendix n Silurian Guelph/Niagaran brines could have, and shown in Figure 21 as a function of the for example, migrated into their present reser age of the rock hosting the brine. Also shown voir. What then appears to be water rock is the curve of Burke et al. (1982), depicting interaction in Guelph time may not be the case the change in the Sr isotopic composition of at all (i.e., there was only fluid migration). seawater with time. Since Sr has a long resi This is possible as then- Sr isotopic values are dence time in the ocean, its concentration and within the expected range for Late Cambrian isotopic composition are uniform throughout time. However, it seems unlikely that there the world©s oceans at any given time (Veizer would be no exchange of Sr between the solid and Compston, 1974). Therefore, there is the and fluid phases. potential for Sr to be used both as a geochro- nological tool for marine sediments and as an indicator of the changes in chemistry that The waters from Upper Cambrian reservoirs occur during diagenesis. It is the latter that is in southwestern Ontario have similar Sr iso of interest in this particular study. topic values to the overlying Trenton Group waters. The uncontaminated Ordovician The Sr seawater curve varies from approxi samples have higher ^Sr/^Sr ratios than mately 0.7095 to 0.7075 from the Upper Cam seawater for all of Phanerozoic time. There-

VNEDITED MANUSCRIPT" 39 300-

1BEREA 350-

•t w i GUELPH X NIAGARAN o THOROLD/GRIMSBY WHIRLPOOL

w i TRENTON /BLACK RIVER c o ,i——(PRAIRIE DU CHIEN 500- l———————————t CAMBRIAN

550-

600 0.707 0.708 0.709 0.710 0.711 0.712 87 86 Sr Sr

Figure 21. Strontium isotopic composition of brines from the Michigan and northern Appala chian! Basins. The sea water curve is from Burke et al. (1982). Note that with few exceptions, the brines are all more radiogenic with respect to sea water for the time in question.

fore, these brines must have experienced some sea water for that period of Silurian time. The water rock interaction. reservoir rock is an evaporite sequence totally dominated by seawater Sr, such that any detri The waters sampled from the Silurian sand tal Rb-bearing phase would contribute a neg stone reservoirs are the most radiogenic ligible amount of ^Sr to the total Sr budget ^Sr/^Sr brines sampled. These highly en and not measurably affect the ^Sr/^Sr ratio. riched waters are clearly the product of water The Salina Formation brines can be inter rock interaction. Future work on the associ preted as a closed system involving no migra ated solid phases will be needed in order to tion in or out of the reservoir. However, it is identify the source of radiogenic Sr. also possible that the water originated else where and has interacted so extensively with The brines from the Upper Silurian Salina the evaporite sequence that the Sr isotopic Formation evaporites are the only waters to value has been "reset". have Sr isotopic compositions consistent with

40 "UNEDITED MANUSCRIPT"

Four of the twenty Middle Silurian rock interaction, similar to the process de Guelph/Niagaran brine samples have ^Sr/^Sr scribed above for the Salina salts. ratios similar to the seawater range for this interval of geologic time (Burke et al., 1982), On balance, it can be concluded that the Sr while the others are all enriched. From Sr isotopic ratios in Michigan Basin brines re isotopic analyses it cannot be ruled out that flect water rock interaction and, as such, can these are connate Middle Silurian waters, but possibly serve as a tracer for fluid migration. it seems more likely that these four waters have interacted with the Salina Formation VARIATIONS IN SR ISOTOPIC evaporite units to produce their Silurian VALUES seawater signature. The Guelph/Niagaran pinnacle reefs are highly porous and perme When the ^Sr/^Sr values are plotted against able water-bearing structures that are closely the reciprocal of the Sr content, the brines are related stratigraphically to the Salina Forma separated into distinct fields that correlate tion salts and anhydrites. If these waters did with the age of their enclosing reservoir rocks come in contact with these closely associated (Figure 22). While the Cambrian and Ordo evaporites, a Silurian seawater ^Sr/^Sr iso vician brines have overlapping isotopic com topic signature could be produced by water positions, they have different ranges of Sr concentration. The Silurian carbonate and

O.OO3 r * *

x -r* X*'"N\'' ^

/^ *A V^ 4 * /^N * */

c 0.002 /^/t ** *\/^*4 ^ */ N. rf * j /* * * * ^ \ x jf \ /' ^^^±^}/'' w x 0.001 ' ^ A v^^^r^^^ tt y7 A A A * Ai* * * x y' O MIMIMIfflAN ' •/v. y 0 mom** 1 9m * \ s* ^-^ m S * WUIWAJi SALT * ^* ^"* —— —' A SIUIMAN CAMONTC V A ^- B * SU.MIAN •ANOttONE ^^*—, ^- -*' * 0 CHOOVieUN CAMMNATE

X CAMtMIAM 0 i i i i i i i o;r08 0.709 0.710 0.7II 87 Sr/ 86 Sr

Figure 22. Strontium isptopic composition versus 1/Sr concentration of Michigan and northern Appalachian! Basin brines.

'UNEDITED MANUSCRIPT" 41 sandstone waters have similar Sr concentra whether or not this similarity is strictly a local tions but different Sr isotopic ratios. phenomenon. A similar relation exists for Sr-618O and Brine samples from the Silurian sandstone and Sr-32H plots (Figures 23 and 24). The Cam Silurian carbonate reservoirs have similar 2H brian and Ordovician samples have very simi values. They have, however, significantly lar ^Sr/^Sr and 2H isotopic values and different ^Sr/^Sr and 18O isotopic ratios. completely overlap one another in one field on These isotopic differences can be quite simply the Sr-^H plot though only show a slight explained by water rock interaction. Brines overlap for the Sr-o*18O plot. This difference from the Guelph/Niagaran reservoirs are most could be caused by a progressive enrichment likely enriched in I8O relative to the clastic- in 18O of the carbonate-hosted Ordovician hosted waters due to oxygen isotopic ex waters relative to the clastic dominated Cam change processes between the waters and the brian reservoirs. It is interesting to note that associated carbonate reservoir rocks. the two Cambrian samples that overlap the The clastic-hosted brines are enriched in Ordovician field on the Sr-818O plot are from ^Sr/^Sr relative to samples from carbonate wells in closest proximity to the Ordovician dominated reservoirs, since there is a greater reservoirs. Unfortunately, at present there is abundance of radiogenic Sr sources (K- feld no Ordovician production in close proximity spar, clay minerals, etc.,...) in these rocks. to the other Cambrian reservoirs to determine

4r- 0 MISSISSIPPIAN 4 A DEVONIAN 3 A 4 SILURIAN SALT Q SILURIAN CARBON/ x SILURIAN SANDSTC 2 0 ORDOVICIAN CARBC * ORDOVICIAN SAND! A CAMBRIAN l

O ~ t ' |0 \ \ ' Q ' 3' -1 - ^^^ ^Afi =:^'_''__ _ . I 1^ ' -/vij?^N 2 -Z V^ 1 ^" O jf*f*G*f*.\ V) \VO' *^oQo 0*^^ } ' o ' 0 0 ll * ~ 3 \ \ ^ ~'~?j*~ - -"3T ~ "^\

O -4 0 \^J /^ \*A.I V ^* X A^X ^~ x X ^ -5 Q ** D

-6

-7

-8

-Q i 1 . t i | 0.708 O.7O9 0.710 0.711 87Sr7 86Sr

Figure 23. Strontium versus oxygen isotopic values of brines from the Michigan and northern Appalachian Basins.

42 'UNEDITED MANUSCRIPT' O MISSISSIPPIAN A DEVONIAN t SILURIAN SALT O SILURIAN CARBONATE x SILURIAN SANDSTONE O ORDOVICIAN CARBONATE * ORDOVICIAN SANDSTONE — KJ A (CAMBRIAN

f-20 /'"^ ^ ^i^ 1-30 !l\ (eo 9 c&i^ ^ \ O A, l ^ ^ 1 ^ A X ^)0 0 ^-^*x""^N \ X^A ^ ^O/-^ X \ X -40 — *~ ~~ \ CVJ /Q jO \ ^~^\ /u ~ Xxy 1 J (w ^^!L ~' *O -50 i*^*^ — — ~- 4 4 V i i i i li i 0.708 0.709 0.710 0.711 'Sr

Figure 24. Strontium versus deuterium isotopic values of brines from the Michigan and north ern Appalachian Basins.

On all diagrams, there are outliers. The Dev mentary basin fluid flow (Toth, 1978) involv onian samples have a wide range in Sr con ing hydrocarbons and Mississippi Valley-type centration, but three of the four samples, have Pb-Zn deposits. Indeed, the age-equivalent consistent ^Sr/^Sr ratios. The one sample rocks in the Illinois Basin contain brines with with the highest value is very dilute with low very similar Sr isotopic ratios to those in the Sr and IDS reflecting the mixing of a brine Michigan Basin (Steuberet al., 1987), indicat with a dilute meteoric water. This dilution is ing very extensive migration of fluid systems better seen through stable isotopes and is re may have occurred. flected in Figure 10 by the negative 818O and 82H values. However, this appears unlikely based on pre The Ordovician data show three interesting sent porosity and permeability considerations. features which require more data for complete As previously stated, these reservoirs are understanding. One is that the brines from the strictly fracture controlled and have virtually edge of the basin in southwestern Ontario and no porosity or permeability away from these southeastern Michigan have, within a fairly features. Therefore, it seems more likely that narrow range, the same isotopic signatures as these Sr isotopic signatures are either the re those from deeper within the basin in southern sult of rock water interaction or that these Michigan (Figures 23 and 24). This supports waters have migrated extensively in adjacent a model of fluid migration over distances of strata that are more porous and permeable. hundreds of kilometres as modeled for sedi The movement of waters into the Ordovician

'UNEDITED MANUSCRIPT' 43 would only occur in areas where fractures signature which is the result of local rock exist. water interaction in essentially a closed sys tem. The two samples from the Albion Scipio The second feature is shown on Figure 25. trend that have extremely low Sr isotopic sig While all of the Ordovician ^Sr/^Sr data fall natures are the result of casing leaks in the within the relatively narrow range of 0.7099 overlying Niagaran Group. This mixing is to 0.7105, each producing field has its own also supported by chemical and stable isotopic still narrower range of values (Figure 25). analyses. The lone sample from the Hillman This suggests that superimposed on the origi Field is probably the result of drilling water, nal isotopic signature, there is a secondary since samples collected from the underlying

BEREA n ~n 'li 1 1 in DUNDEE MI. --'0NT-^-^

I 1 I 1 1 1 T RICHFIELD

'l 1 l 1 1 1 l F SALT

I* ' l I 1 I 1 l A2 SALT r~i. i

2^— NIAGARAN

GUELPH/ f HGUELPH NIAGARAN pi ra | | n

i i ' n i M n i n ni i

WHIRLPOOL ( i ii i i i ALBION SCIPIO STONEY POINT

\\ P^l?//B K —— HILLMAN TRENTON m , pi p Ba riSifls^^ P du C —————^H ——— , f~l . —————n —————, ————— ,————— , CAMBRIAN , , R l~rn 0.708 0.709 0.710 0.711 87SrX 86 Sr

Figure 25. Sr isotopic composition versus reservoir age displaying groupings of Ordovician res ervoirs by individual fields. Sea water Sr ranges are from Burke et al. (1982).

44 'UNEDITED MANUSCRIPT" Cambrian sandstone and overlying Silurian brine with a significantly different Sr ratio of carbonate strata have Sr isotopic signatures 0.7090. similar to all of the other Hillman wells. However, the preliminary analyses of the Thirdly, in the Albion Scipio, Stoney Point, solid phases in this field add another dimen and Hillman Fields there appear to be compo- sion to the problem. Five matrix dolomite sitionally different zones. In both the Albion samples from the host rock in this field give Scipio and Stoney Point Fields, there is an Sr values of 0.7086 0.0002. This value is apparent decrease in radiogenic Sr as one the same as the sea water curve of Burke et al. moves from north to south along these narrow (1982) indicating little change has taken place fracture controlled reservoirs. The Hillman since the end of deposition and burial diage Field is a much smaller reservoir in volume nesis. Likewise, late stage vein and vug fill and areal extent (when compared to the two ings including saddle dolomite, calcite and previously mentioned fields in southern anhydrite from one of the holes (brine value Michigan). The smaller size of the field and 0.7103) have the same Sr values as the host the denser sample control are probably re matrix dolomites. These values are consistent sponsible for the close similarity of most Sr with the sea water value for the time period. isotopic ratios in this field. There are three Late stage minerals from the hole containing distinct zones in this field based upon Sr iso the anomalously low brine value (0.7090) topic analyses. From further work on the show a very different pattern. Samples of associated solids, it is hoped that a possible saddle dolomite and anhydrite from this hole explanation for these anomalous values can be have ratios similar to the present day brine in determined. the rest of the field (0.7103) and yet different from the matrix (0.7086).

MINERAL AND ROCK SR DATA The data from these two holes present con To assess the extent of water rock interaction flicting results. In one hole, the rock and between the brines and the reservoir rocks up secondary mineral phases have not isotopi- to the present time, the rock and late stage cally equilibrated with the present-day brine. diagenetic mineral phases coexisting with In the other, some of the secondary mineral several of the brines are being analyzed. phases have apparently equilibrated with the dominant Hillman Field brine, even though Detailed study of the Hillman Field in south this brine is not now present in this hole. A western Ontario has further shown the com later brine with the 0.7090 signature is pre plexity of interaction between formation sent; and it appears that calcites and one sul brines and host rock. Eleven wells were sam phate sample, with ratios of 0.7087 to 0.7088, pled for formation waters in the field Ten have partially equilibrated with it. The Hill brine samples, each from a producing well man Field has had a complex history of fluid were analyzed and the average ^Sr/^Sr value migration and diagenesis that obviously needs is 0.7103 0.0001. The remaining well had a more study.

'UNEDITED MANUSCRIPT' 45 SUMMARY

Several conclusions can be drawn on the basis Guelph/Niagaran: Although waters from of this work: these reservoirs plot in unique positions on most plots, they also display the greatest vari 1. Very concentrated brines ^300 g/1 TDS) ability. This dispersive behaviour reflects the exist in most strata. These brines are usually diverse nature of the adjacent carbonate and Ca-Na-Cl in composition although some vari evaporite lithologic units. ability of Ca/Na does occur. Dundee Formation: At depth in the central Michigan Basin, the Dundee Formation is 2. The most concentrated waters from each characterized by very concentrated brines, unit have similar isotopic and geochemical while near areas of recharge in southwestern characteristics which are distinct from the Ontario, they are dilute saline waters. Dev concentrated brines of the other units. Se onian-aged strata in southwestern Ontario lected anomalous units are dicussed below: usually contain much more dilute saline wa ters (TDS ^0 g/1), whose stable isotopic sig Trenton-Black River and Cambrian: Al nature (818O and 62H) would suggest that they though the waters from Cambrian reservoirs have a component that was derived during a are generally much more concentrated than cooler climate, probably the last period of the Ordovician waters, they show a remark deglaciation. able amount of overlap on several of the vari ous chemical and isotopic plots discussed. 3. Strontium isotope analysis of the brines shows that rock water interaction must have Thorold/Grimsby/Whirlpool: Waters from occurred to explain the radiogenic ^Sr/^Sr these sandstone producing reservoirs display values compared to sea water. Since Sr is a areal trends in major cation species. Samples sensitive indicator of the nature and extent of from under eastern Lake Erie are Na-Ca-Cl rock water interaction, it is a very useful tool brines while waters from Norfolk County and for the study of mixing and migration of brines central Lake Erie are Ca-Na-Cl brines. in sedimentary basins.

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WHITE, D.E. 1965 Saline waters of sedimentary rocks: Amer. Assoc. Petrol. Geol. Memoir 4, p. 342- 366.

56 "UNEDITED MANUSCRIPT" WHITE, D.E., HEM, J.D. and WARING, G.A. 1963 Chemical composition of subsurface waters. U.S. Geol. Survey Prof. Paper 440-F, 67p.

WINDER, C.G. and SANFORD, B.V. 1972 Stratigraphy and paleontology of Paleozoic rocks of southern Ontario: Excursion A45-C45, Guidebook, 24th session, Int. Geol. Congress, Montreal.

ZHEREBTSOVA, I.K. and VOLKOVA, N.N. 1966 Experimental study of behavior of trace elements in the process of natural solar evaporation of Black Sea water and Sasyk-Sivash brine. Geochem. Int. 3,656- 670.

'UNEDITED MANUSCRIPT" 57 APPENDIX l

Subsurface Water Nomenclature Water Definitions

Meteoric Water: White (1957) has defined the term to apply to "water that was recently involved in atmospheric circulation. The age of meteoric groundwater is slight when compared with the age of the surrounding rocks and is not more than a small part of a geologic period," Kharaka and Carothers (1986) have modified the term by removing the time of last contact from the original definition as the time required for water to percolate to great depths and distances from recharge areas may require millions of years.

Connate Water: Water which has been deposited with sediments or other rock in the basin and that has been out of contact with the atmosphere since its deposition (Kharaka and Carothers, 1986).

Diagenetic Water: Water that has been released from solid phases as a result of mineral transformations that occur during diagenesis. These waters would commonly be associated with smectite to illite transformations (expulsion of interlayer waters) and hydration/dehydration reac tions between gypsum and anhydrite.

Formation Water: Case (1955) has defined formation water as "water present in rocks immedi ately before drilling." This term has been widely used since it has no genetic or age significance.

Additional water terms are presented in White (1957,1965) and White et al. (1963)

'UNEDITED MANUSCRIPT' 59 APPENDIX II

Chemical and Isotopic Data

'UNEDITED MANUSCRIPT" 61 SAMPLE AGE GROUP/ Ca Na Mg K # FORMATION (mg/l) (mg/1) (mg/l) (mg/l)

MB-1 Miss. Berea 41100 51200 8760 799 MB-2- Miss. Berea 43600 59400 9160 861 MB-3 Miss. Berea 37800 51000 7500 732 MB-4 Miss. Berea 33000 43500 6320 545 MB-5 Miss. Berea 40900 59600 8060 697 MB-6 Miss. Berea 35100 64300 7080 795 DD-1 Devonian Dundee 660 3690 632 85 DD-2 Devonian Dundee 623 414 83 19 DD-3 Devonian Dundee 31500 70600 5410 3030 DD-4 Devonian Dundee 40300 56600 6990 3370 DR-1 Devonian Richfield 64900 23400 7960 8320 SF-1 Silurian F Salt 8200 100000 2850 2600 SF-2 Silurian F Salt 10300 94500 3100 2780 SF-3 Silurian F Salt 9630 94400 3370 2600 SA2-1 Silurian A2Salt 48400 33400 16600 5000 SA2-2 Silurian A2 Salt 46800 33600 16200 6400 SA1-1 Silurian Al Carbonate 52000 37700 11400 4520 SA1-2 Silurian Al Carbonate 54700 37900 10900 4760 SG-1 Silurian Guelph 15000 41200 3780 1430 SG-2 Silurian Guelph 31300 65500 7770 1880 SG-3 Silurian Guelph 44500 61300 9000 2740 SG-4 Silurian Guelph 60300 46600 8250 3040 SG-5 Silurian Guelph 29000 70000 8200 2040 SG-6 Silurian Guelph 53700 42100 9520 3240 SG-7 Silurian Guelph 66000 42300 8440 3270 SG-8 Silurian Guelph 61500 46000 10600 3400 SG-9 Silurian Guelph 53100 42900 13300 2150 SG-1O Silurian Guelph 57200 39400 8670 3340 SG-11 Silurian Guelph 52600 49900 9500 4840 SG-12 Silurian Guelph 34700 53200 7080 2390 SG-13 Silurian Guelph 50200 54800 8230 2810 SN-1 Silurian Niagaran 62000 40800 8680 6080 SN-2 Silurian Niagaran 61300 40300 8530 5920 SN-3 Silurian Niagaran 73800 24800 17900 8560 SN-4 Silurian Niagaran 78500 25300 17900 9280 SN-5 Silurian Niagaran 77300 31000 11900 10300 SN-6 Silurian Niagaran 79500 25200 15500 9820 SN-7 Silurian Niagaran 62900 45300 8550 4320 SN-8 Silurian Niagaran 61900 45100 8080 3900 SN-9 Silurian Niagaran 54900 46000 9600 3560 SN-1O Silurian Niagaran 62600 42600 8530 3370

62 SAMPLE CI Br S04 IDS 87786Sr 18Q 2H # (mg/l) (mg/l) (mg/l) (mg/l) (SMOW) (SMOW)

MB-1 183800 1340 54 288600 0.70893 -1.5 -32 MB-2 196700 1460 CIS 312900 0.70899 0.3 -24 MB-3 169600 1250 CIS 269400 0.70904 -2.1 -45 MB-4 144300 1080 18 230100 0.70915 -3.9 -52 MB-5 194400 1310 CIS 306500 0.70905 0.2 -31 MB-6 194800 1180 66 304500 0.70807 0.5 -25 DD-1 10000 50 795 15940 0.70852 -11.4 -86 DD-2 2000 12 98 3260 0.70949 -15.7 -120 DD-3 179000 1050 166 291500 0.70816 DD-4 182200 1310 150 292000 0.70823 -0.9 -34 DR-1 173100 1970 205 281900 0.70913 0.2 -55 SF-1 207000 587 750 322200 0.70866 -5.5 -55 SF-2 194100 390 510 305900 SF-3 192900 325 595 304000 -4.7 -52 SA2-1 232000 3220 110 340400 0.70853 2.9 -52 SA2-2 232000 3214 106 340000 0.70866 3.2 -48 SA1-1 176000 1880 167 284400 SA1-2 195300 1700 193 306400 0.70849 -1.1 -47 SG-1 95500 810 810 158800 0.71029 -4.7 -42 SG-2 189100 1390 250 297600 0.70931 SG-3 206900 1620 127 326800 -0.8 -43 SG-4 197800 2510 119 319800 0.70915 SG-5 189100 1390 259 300400 0.70934 SG-6 186300 1780 227 297600 0.70889 SG-7 210900 2440 239 334700 0.70946 SG-8 214600 2010 61 339200 0.70908 -0.4 -44 SG-9 205500 1490 203 319200 0.70929 SG-1O 189500 2380 172 301900 0.70902 SG-11 213700 1920 170 333300 0.70893 SG-12 155200 1510 300 255000 0.70931 SG-13 208200 1920 170 327000 0.70907 SN-1 209700 2160 79 330800 0.70833 0.2 -42 SN-2 208500 1880 79 327800 -1.4 -48 SN-3 230400 2390 59 359900 -2.9 -50 SN-4 256200 2360 38 391700 0.70861 -4.9 -46 SN-5 245300 2440 42 380300 1.2 -40 SN-6 261800 2640 49 397000 0.70848 -1.0 -47 SN-7 210700 2270 94 335300 0.70935 0.2 -43 SN-8 187800 2240 105 310300 0.70939 -0.5 -41 SN-9 207100 1970 89 324100 0.70909 -0.4 -43 SN-1O 202500 2320 89 323100 0.70929 -0.1 -47

'UNEDITED MANUSCRIPT' 63 SAMPLE AGE GROUP/ Ca Na Mg K # FORMATION (mg/l) (mg/1) (mg/l) (mg/l)

STGr-1 Silurian Thorold/Grimsby 29000 48100 5980 1000 STGr-2 Silurian Thorold/Grimsby 36700 51900 7030 1410 STGr-3 Silurian Thorold/Grimsby 27400 42200 6620 899 STGr-4 Silurian Thorold/Grimsby 34700 49400 6100 981 ST-5 Silurian Thorold/Grimsby 30500 44500 5830 1010 ST-6 Silurian Thorold 33700 45200 6210 1040 SGr-7 Silurian Grimsby 33600 50600 5880 1010 SGr-8 Silurian Grimsby 34200 49500 5840 1130 STGr-9 Silurian Thorold/Grimsby 42100 49700 7500 1260 STGr-lO Silurian Thorold/Grimsby 45700 58000 8000 1390 SGr-11 Silurian Grimsby 44600 58700 7700 1450 SGr-12 Silurian Grimsby 26900 38900 5310 878 STGr-13 Silurian Thorold/Grimsby 31400 45100 5630 877 STGr-14 Silurian Thorold/Grimsby 47700 58600 8230 1400 SGr-15 Silurian Grimsby 34600 46900 6280 930 SGr-16 Silurian Grimsby 28100 45800 4870 911 STGr-17 Silurian Thorold/Grimsby 29100 43300 5070 846 SGr-18 Silurian Grimsby 39700 22800 6780 664 SGr-19 Silurian Grimsby 39800 20900 3540 637 SGr-20 Silurian Grimsby 42700 30300 5470 822 SGr-21 Silurian Grimsby 42000 26400 3930 713 SW-1 Silurian Whirlpool 50400 32400 4250 782 SW-2 Silurian Whirlpool 47300 29900 3710 763 SW-3 Silurian Whirlpool 51100 36400 5500 870 SW-4 Silurian Whirlpool 43400 28200 4460 770 OT-1 Ord. Trenton 15600 35700 3680 1600 OT-2 Ord Trenton 16000 35300 3510 1600 OT-3 Ord. Trenton 15800 35800 3500 1630 OT-4 Old. Trenton 23300 39800 5480 1970 OT-5 Ord. Trenton 23500 41400 6130 2120 OT-6 Oni. Trenton 17400 36900 4280 1690 OT-7 Ord. Trenton 35200 43600 7410 2310 OT-8 Ord. Trenton 32600 46800 6520 2410 OT-9 Ord. Trenton 36500 48800 7410 2270 OT-1O Ord Trenton 36700 48700 7930 2330 OT-11 Ord. Trenton 36730 45700 7270 2320 OT-12 Ord. Trenton 39200 45300 6910 2120 OT-13 Ord Trenton 32600 55200 7300 2390 OT-14 Ord Trenton 33000 48700 6750 2390 OT-15 Ord. Trenton 31300 46100 6530 2300 OT-16 Ord Trenton 32800 46100 6600 2680

64 'UNEDITED MANUSCRIPT" SAMPLE AGE GROUP/ Na Mg K # FORMATION (mg/1) (mg/l) (mg/l)

OT-17 Ord. Trenton 29700 43200 5960 2150 OT-18 Ord. Trenton 34100 45400 6700 2310 OT-19 Od. Trenton 31100 42000 5440 2190 OT-20 Old. Trenton 27200 46500 5170 2080 OT-21 Ord. Trenton 32500 49700 5960 2070

'UNEDITED MANUSCRIPT' 65 SAMPLE CI Br S04 TDS 87786Sr 18Q 2H # (mg/l) (mg/l) (mg/l) (mg/l) (SMOW) (SMOW)

STGr-1 137600 1340 385 223900 -3.5 -43 STGr-2 158500 1550 259 258000 0.70977 -2.9 -34 STGr-3 129400 1260 447 208700 -4.2 -44 STGR-4 149200 1580 320 242800 -2.9 -43 ST-5 148100 1340 413 232200 0.71014 -4.1 -46 ST-6 143400 1430 339 231900 -3.4 -44 SGr-7 160800 1510 332 254300 -3.3 -43 SGr-8 164300 1540 345 257400 -3.0 -42 STGr-9 179000 1650 272 282200 -2.8 -44 STGr-lO 195800 1970 164 311800 -1.9 -42 SGr-U 178300 1870 174 293500 -1.7 -41 SGr-12 117500 1130 657 191700 -3.9 -40 STGr-13 144300 1380 423 229600 3.4 -41 STGr-14 207000 2010 123 325900 0.71018 -1.7 -46 SGr-15 163600 1490 404 254800 -3.5 -39 SGr-16 144200 1250 530 226100 0.71076 -3.4 -35 STGr-17 142200 1260 450 222700 -2.9 -41 SGr-18 109200 755 560 180800 -4.3 -44 SGr-19 119400 694 235 185600 0.71092 -4.5 -44 SGr-20 137400 920 405 218500 0.71036 -3.7 -38 SGr-21 112600 855 329 187300 3.8 -43 SW-1 158800 1130 320 248600 0.71103 -3.0 -39 SW-2 147500 1000 376 231000 0.71107 -3.7 -41 SW-3 171600 1190 375 267500 -2.5 -39 SW-4 126100 920 433 204700 0.71112 -3.8 -42 OT-1 98700 578 453 156900 0.70978 -2.1 -31 OT-2 99800 725 742 158200 0.70980 -1.7 -23 OT-3 101100 563 575 159400 0.70976 -1.9 -31 OT-4 111300 832 630 183700 0.70996 -1.7 -30 OT-5 131800 856 152 206700 0.70973 -1.9 -29 OT-6 103200 550 410 165000 0.70982 -2.2 -28 OT-7 149500 920 263 239800 OT-8 148100 1190 353 238500 0.71041 -2.1 -30 OT-9 150500 950 263 247300 0.70900 -2.1 -27 OT-1O 175900 1170 260 273600 0.71029 -2.3 -31 OT-11 160900 1610 271 255500 0.71030 -1.9 -26 OT-12 166100 1370 321 262100 0.71030 -2.0 -29 OT-13 161200 1150 320 260700 0.71007 -2.1 -27 OT-14 141400 1170 358 234300 0.71036 -2.0 -33 OT-15 149500 1120 380 237800 0.71023 -2.2 -27 OT-16 148600 1220 347 238900 0.71034 -2.1 -36

66 'UNEDITED MANUSCRIPT" SAMPLE CI Br S04 TDS 87786Sr 180 2H # (mg/l) (mg/l) (mg/l) (mg/l) (SMOW) (SMOW)

OT-17 138600 1270 366 221800 0.71036 OT-18 158300 1210 348 249000 0.71036 OT-19 147000 780 393 229400 -1.8 -24 OT-20 142300 765 485 225000 -2.0 -23 OT-21 150300 1190 335 242700 0.71045 -3.1 -32

'UNEDITED MANUSCRIPT" 67 SAMPLE # AGE GROUP/ Ca Na Mg K FORMATION (mg/l) (mg/1) (mg/l) (mg/l) OT-22 Ord Trenton 21700 41900 4470 3230 OT-23 Ord Trenton 31000 48000 5450 3390 OT-24 Ord. Trenton 21800 42300 4270 3130 OT-25 Ord. Trenton 18300 40300 3790 3060 OT-26 Ord. Trenton 19200 41300 4360 3330 OT-27 Ord. Trenton 20500 42500 4620 3490 OT-28 Ord. Trenton 19800 42000 4320 3460 OT-29 Ord. Trenton 21400 41200 4670 3490 OT-30 Ord. Trenton 54900 53200 7790 5250 OT-31 Ord. Trenton 23800 46200 5070 3960 OT-32 Ord. Trenton 23800 45900 5170 3770 OT-33 Ord. Trenton 21600 41900 4110 3890 OT-34 Ord. Trenton 22200 44100 4280 3990 OT-35 Ord. Trenton 20700 42500 4090 3650 OT-36 Ord. Trenton 21400 42500 3960 3770 OT-37 Ord. Trenton 20900 43000 4130 3760 OT-38 Ord. Trenton 25300 41800 4720 3300 OT-39 Ord. Trenton 13100 38800 3670 2010 OT-40 Ord. Trenton 9850 36400 3720 1840 OT-41 Ord. Trenton 10800 36400 3850 1850 OT-42 Ord Trenton 10500 37500 3670 1880 OP-1 Ord. Prairie du 68000 26700 7200 Chien 14200 OP-2 Ord Prairie du 87500 22600 8700 Chien 18400 C-l Cambrian (Undivided) 47900 41000 6750 1410 C-2 Cambrian (Undivided) 60000 47700 6710 1340 C-3 Cambrian (Undivided) 60200 48500 6680 1330 C-4 Cambrian (Undivided) 57800 49900 7710 1480 C-5 Cambrian (Undivided) 32100 24900 3240 645 C-6 Cambrian (Undivided) 22400 40100 4380 2060 C-7 Cambrian (Undivided) 46500 43400 5860 1380 C-8 Cambrian (Undivided) 51200 50800 6510 1810 C-9 Cambrian (Undivided) 52800 45000 7060 156017 C-1O Cambrian (Undivided) 50500 43600 6900 1550 C-ll Cambrian (Undivided) 43600 47700 5340 1570 C- 12 Cambrian (Undivided) 53500 42100 5670 1150 C-13 Cambrian (Undivided) 54800 44200 7180 937

68 'UNEDITED MANUSCRIPT' SAMPLE CI Br S04 TDS 877865r 18Q 2H # (mg/l) (mg/l) (mg/l) (mg/l) (SMOW) (SMOW)

OT-22 122700 625 620 195700 0.70962 OT-23 159800 1160 327 249700 0.70887 -1.3 -45 OT-24 122000 925 402 195300 0.70958 -1.7 -27 OT-25 117600 797 538 184800 0.71000 -2.0 -27 OT-26 118500 857 256 188300 0.70991 -2.1 -27 OT-27 123200 917 312 196000 0.70977 -1.9 -26 OT-28 119400 650 622 190700 0.70980 OT-29 117600 917 418 190200 0.70985 -1.6 -24 OT-30 222000 1780 129 346100 0.70827 0.4 -35 OT-31 137300 909 411 218200 0.70992 -1.7 -20 OT-32 134100 890 400 214600 -1.5 -25 OT-33 117500 725 460 190700 OT-34 133000 911 474 209500 0.71027 -1.8 -29 OT-35 126400 872 535 199300 0.71010 -1.8 -25 OT-36 126100 650 505 199400 OT-37 125700 877 491 199400 0.71003 -1.5 -33 OT-38 131800 789 507 208700 0.70994 -2.4 -34 OT-39 101900 510 415 160900 0.70958 -2.7 -26 OT-40 86600 460 66 139500 0.70929 -3.0 -28 OT-41 87000 440 66 140900 0.70938 -2.8 -28 OT-42 87500 460 ^5 142100 0.70929 -2.6 -28 OP-1 205000 1930 63 325400 0.70930 -1.6 -50 OP-2 249700 1780 ^0 391500 0.70923 C-l 179000 1680 277 279200 0.71028 -4.0 -29 C-2 218700 1420 52 337600 0.71002 -4.4 -28 C-3 205600 1550 47 325600 -4.6 -28 C-4 186100 1710 96 306000 0.70990 -4.6 -35 C-5 110100 1110 980 174100 0.70957 -4.1 -36 C-6 108400 792 645 179200 0.71007 -1.4 -28 C-7 176500 1510 247 276600 0.70986 -3.3 -21 C-8 193400 2260 134 307400 0.70990 -3.3 -28 C-9 191800 1450 131 301100 0.70980 -3.6 -29 C-1O 183800 1440 169 289200 -3.8 -32 C-ll 168700 1610 210 269900 0.71029 -2.0 -24 C-12 183000 1770 138 288600 C-13 194900 1835 146 305200 0.70951

'UNEDITED MANUSCRIPT" 69

APPENDIX III

Dissemination of Results Papers and Conference Abstracts

1) The following two abstracts have been presented as well as two additional presentations on the data by Dollar and Frape at the Ontario Petroleum Institutes©s annual meeting in 1987.

Frape S.K., Dollar, P., Fritz, P., Macqueen, R.V. and McNutt, R.H. 1986 Geochemistry and isotopic compositions of formation waters from southern On tario; Presented at the Joint Annual Meeting of the Geological Association of Can ada - Mineralogical Association of Canada, Ottawa, Ontario, May, 1986. Frape S.K., Dollar, P., Fritz, P., Trevail, R.A., Macqueen, R.V. and McNutt, R.H. 1986 Implications of formation water movement based on isotopic data and elemental geochemistry, southwestern Ontario; Presented at the 50th Anniversary Sympo sium of the Michigan Basin, American Association of Petroleum Geologists, East ern Section, Ann Arbour, Michigan, October, 1986. 2) The following referreed paper has been written and several other papers on aspects of the work are in preparation. McNutt, R.H., Frape, S.K. and Dollar, P. 1987 A strontium, oxygen and hydrogen isotopic composition of brines, Michigan and Appalachian basins, Ontario; Applied Geochemistry, v.2, p.495-505.

3) The work has lead to ongoing collaborative studies with several groups in Northern United States and additional joint publications and presentations are planned.

4) Immediate spinoffs are the work of Coniglio and others and ourselves to continue the rock-water interaction aspects of the study.

"UNEDITED MANUSCRIPT' 71 CONVERSION FACTORS FOR MEASUREMENTS IN ONTARIO GEOLOGICAL SURVEY PUBLICATIONS

Conversion from SI to Imperial Conversion from Imperial to SI SI Unit Multiplied by Gives Imperial Unit Multiplied by Gives LENGTH 1 mm 0.039 37 inches 1 inch 25.4 . mm 1 cm 0.393 70 inches 1 inch 2.54 cm 1m 3.28084 feet 1 foot 0.304 8 m 1m 0.049 709 7 chains 1 chain 20.116 8 m 1km 0.621 371 miles (statute) 1 mile (statute) 1.609 344 km AREA 1cm2 0.155 0 square inches 1 square inch 6.451 6 cm2 1m2 10.763 9 square feet 1 square foot 0.092 903 04 m2 1km2 0.386 10 square miles 1 square mile 2.589 988 km2 lha 2.471 054 acres 1 acre 0.404 685 6 ha VOLUME 1 cm3 0.061 02 cubic inches 1 cubic inch 16387 064 cm3 1m3 35.314 7 cubic feet 1 cubic foot 0.028 316 85 m3 1m3 1.308 0 cubic yards 1 cubic yard 0.764 555 m3 CAPACITY 1L 1.759 755 pints 1 pint 0.568 261 L 1L 0.879 877 quarts 1 quart 1.136 522 L 1L 0.219 969 gallons 1 gallon 4.546 090 L MASS lg 0.035 273 96 ounces (avdp) 1 ounce (avdp) 28.349 523 g lg 0.032 150 75 ounces (troy) 1 ounce (troy) 31.103 476 8 g 1kg 2.20462 pounds (avdp) 1 pound (avdp) 0.453 592 37 kg 1kg 0.001 102 3 tons (short) 1 ton (short) 907.184 74 kg It 1.102311 - tons (short) 1 ton (short) 0.907 184 74 t 1kg 0.000 984 21 tons (long) 1 ton (long) 1016.046 908 8 kg It 0.984 206 5 tons (long) 1 ton (long) 1.016 046 908 8 t CONCENTRATION Ig/l 0.029 166 6 ounce (troy)/ 1 ounce (troy)/ 34.285 7142 g©i ton (short) ton (short) Ig/l 0.583 333 33 pennyweights/ 1 pennyweight/ 1.714 285 7 g©l ton (short) ton (short) OTHER USEFUL CONVERSION FACTORS Multiplied by 1 ounce (troy) per ton (short) 20.0 pennyweights per ton (short) 1 pennyweight per ton (short) 0.05 ounces (troy) per ton (shorl)

Note: Conversion factors which arc in bold type are exact. The conversion factors have been taken from or have been derived from factors given in the Metric Practice Guide for the Canadian Mining and Metallurgical Indus tries, published by tlie Mining Association of Canada in co-operaiion tvilh the Coal Association of Canada.

72