DOCSLIB.ORG

Paleomagnetic Indications for a Late Paleozoic Age for Part of the Watrous Formation, Williston Basin, Southern Saskatchewan

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Paleomagnetic Indications for a Late Paleozoic Age for Part of the Watrous Formation, Williston Basin, Southern Saskatchewan Paleomagnetic Indications for a Late Paleozoic Age for Part of the Watrous Formation, Williston Basin, Southern Saskatchewan 1 1 2 Randolph J Enkin , Judith Baker , and K. G. Osadetz Enkin, R.J., Baker, 1. , and Osadetz, K.G. (2001): Paleomagnctic indications for a Late Paleozoic age for part of the Watrous Formation, Williston Basi n, southern Saskatchewan; in Summary of In vestigations 200 1, Volume I, Saskatchewan Geological Survey, Sask. Energy Mines, Misc. Rep. 2001-4.1. l. Introduction Saskatchewan, Manitoba, and the adjacent United States of America (Figure I). The basin contains The Williston Basin is a Phanerozoic epicratonic basin several significant petroleum provinces and mineral about 800 km in diameter underlying southern deposits (e.g. Burrus et al., 1996), and has thus been the focus of detailed exploration. SASKATCHEWAN MANITOBA However, there remain profound uncertainties concerning the origin, tectonics, and even _..-. Petroleum ..... Province stratigraphy of the basin. These uncertainties hamper the Depth to base of understanding of its petroleum Carboniferous (m) systems. The Watrous Formation (Milner and Thomas, 1954) is composed of red bed siliciclastics and anhydrites (Christopher, 1984; Edwards et al., 1994 ). The formation onlaps a major regional unconformity underlain by the deeply eroded Paleozoic carbonate succession (Figure 2). These usually " tight" rocks are commonly cap rocks to the Mississippian subcrop oil fields. The formation has been a minor ----- oil producer, from more sandy porous lithologies, as typified by the Waskada Field in southwestern Manitoba that was discovered in 1980. The Watrous Formation is informally split into "upper" and " lower" members. The upper Middle Devonian member is dominated by '""'"''~ anhydrites and is considered to be of Jurassic age (Christopher, 1984). The lower member has been correlated to the Lower Figure 1 (detail) Jurassic upper Spearfish Formation which crops out in North Dakota. Others suggest this member may be as young as Middle Jurassic (see Edwards et al., 1994). Figure 1 .. Regional setting, major tectonic elements, and petroleum provinces ofthe Williston Basin. Basi11form-lines are indicated by the depth to the base ofth e Carbo11iferous Madison Group. I Geological Survey of Canada - Pacific, 9860 West Saanich Road, POB 6000, Sidney, BC V8L 482. 2 Geological Survey of Canada, 3303 - 33rd Street NW, Calgary, AB T2L 2A7. 72 Summary ofInv estigations 200/, Volume I (km) Fonnation is underlain by the 0 100 200 300 Charles Fonnation of the Carboniferous Madison Group. NNE SSE N s 2. Methods We drilled 2.5 cm diameter minicores perpendicular to the core axis. Since the original core _o was almost vertical, our E minicores were taken parallel to ~ the near- horizontal strata. Where c .2 CRETACEOUS the rock was massive and red­ j .!! pigmented, we sampled every 2 w to 3 ft (60 to 90 cm). Magnetic remanence was JURASSIC measured on an Agico JR5-A TRIASSIC spinner magnetometer. Magnetic PERMIAN susceptibilities were measured using a Sapphire SI2-B meter. We measured both full core and minicore susceptibility. Thermal demagnetizations were performed with an ASC TD-48 furnace, over 12 to 15 steps up to 700°C. Imperial* Herald Magnetic remanence directions 1-31-1-20W2 were determined by Principal .~I:. =- I. Triassi<;. .. Component Analysis, using programs developed by the first lower tJ r-re~ian author (available on request). Watrous { 'VVVV'\, tf] I~:~~sylvanian 3. Results The core of the lower Watrous - - consists mostly of red to orange Figure l - Section of Williston Basin illustrating the Phanerozoic stratigraphic mudstone to siltstone with rare succession after Burrus et al. (1996). Location ofthis section is indicated in Figure I. beds of sandstone. Common The interpreted stratigraphic position ofthe lower member ofthe Watrous in the ripple marks and cross bedding analyzed core is shown in the inset in the lower left-hand corner ofthe diagram. indicate shallow-water deposition. Reduction spots are In an attempt at better determining the age of this non­ common, and usually have sharp fossiliferous formation, we sampled core from an oil edges. They are early diagenetic features, and exploration well for paleomagnetic study. The apparently have not been altered by subsequent fluid observed magnetic inclination gives the paleolatitude at motions. which the rocks were situated at the time of magnetization. By comparing the paleolatitude history Characteristic demagnetization curves are plotted in of the site, derived from North America's apparent Figure 3. The natural remanent magnetizations (NRM) polar wander path (APWP), with the observed are typical of red sediments (geometric mean paleolatitude, we can detennine the age of the 5.34 mA/m ±48%). The samples are relatively magnetization. If the magnetization is primary, we can efficiently magnetized (Koenigsberger ratio KN= date the age of sediment deposition. NRM/induced magnetization = 1.34 ±45%) compared to similar rocks which usually have KN < 1. However, We sampled the Imperial Herald core (1-31-1-20W2; about half of the magnetization is a drilling induced 49.1 °N, I 04.5°W, approximately 160 km south of overprint. This component, roughly parallel to the Regina), because it lies near the centre of the Williston direction ofminicoring, is removed by heating to 150° Basin and has excellent recovery of the lower member or 200°C. The remaining magnetization remains very of the Watrous Fonnation. The Watrous Formation was stable to about 500°C. The dominant magnetic carrier picked between depths of 5206 and 5593 ft (1586.8 is clearly hematite (with a Curie Temperature Tc = and 1704.7 m), and the bottom 110 feet (33.5 m) were 680°C), as most of the stable magnetization unblocks almost continuously recovered. The Watrous between 600° and 700°C heating, well above the Tc of magnetite, 580°C. The remanence direction held by the hematite is easily determined by line-fitting this high Saskatchewan Geological Survey 73 lower Watrous Group A: 5515 feet attempted to orient the core NN • Lower N 6.25mA/m using the faint present-fi eld eo nupper overprint which survived the drilling overprint. The resolution is low, but we find north-west declinations in the A group, and southerly declinations in the B group. This indicates that the A group is truly normal polarity, while the B group has reverse o , oo 300 soo 1oo·c polarity and is not a normal polarity magnetization from lower Watrous Group A: 5546 feet when North America was NN situated in the southern eo 3 75mA/m hemisphere. The mean inclination of group A is 25.1° ±4.1° , N = 49, Fisher precision k = 14.9 (method of Enkin and Watson, 1996). This 6 75'C observed inclination is consistent with the expected inclination derived from the North American APWP for ages between 209 to 3 1 1 Ma lower Watrous Group B: 5570 feet (Pennsylvanian through Triassic) NN ea 6.1mA/m (Figure 5). Note, in particular, that North America drifted rapidly northward during latest Triassic and Early Jurassic time, and that the expected incl ination fo r all more recent times is far steeper than what we observe. 675'C Thus we can be sure that these rocks did not suffer a post­ 0 100 300 500 Triassic remagnetization. lower Watrous Group B: 5576.5 feet f he observed polarity is normal, NN eo 5.92mAlm and during most of Pennsylvanian and Permian times, the geomagnetic field has persistent reverse polarity, a period known as the Kiaman Reverse Chron. Thus we conclude that the age of this interval of the Watrous Formation is between latest Pennian to Triassic time (260 to 209 Ma), likely during one Figure 3 - Typical demagnetization characteristics oflo wer Watrous Formation nonnal polarity chron. specimens, illustrated as orthogonal projections, stereographs, and magnetic intensity as a/unction oftherma l demagnetization step. The B group has significantly shallower inclination (- 13 .5° temperature segment. About 20% of the samples were ±3.8°, N = 25, k = 34.7). This result is consistent with unsuitable, since the remanence was demagnetized at the North American APWP between the ages of 351 much lower temperatures and gave either incoherent and 303 Ma (Mississippian th rough Pennsylvanian) directions, or only drilling overprint directions. (Figure 5). There are reversals before the Kiaman Reverse Chron, so it is not possible to constrain the age The observed remanence directions clearly separate using magnetic polarity as confidently as with th e A into two groups (Figure 4). The A group, from depths group. But since we observed no reversals in this of5484 to 5560 ft (167 1.5 to 1694.7 m), has positive interval of the core, we consider it likely to have post­ (down) inclinations, while the 8 group, from 5563 to dated the start of the Kiaman at about 3 15 Ma. 5583 ft ( 1695.6 to 1701.7 m), has negative (up) inclinations. The declinations are random. However, from core segments which we could piece together, we 74 Summary of Investigations 200 I, Volume I concerning the age and correlation of that formation, N and in this respect the present report is no exception". •Lower They go on to say, " We maintain the tradition". While A Upper recognizing the preliminary nature of our study, we feel confident in saying that the lower Watrous 1, recovered in the Imperial Herald core was not • deposited after Triassic time, and is most likely latest • Permian to Triassic in age. Furthermore, a period of • • tens of millions of years is missing near the bottom of • the Watrous in this core. The lowest 20 ft (6. 1 m) is of • ) Paleozoic, probably mid-Pennsylvanian, age. + Our study on sub-Watrous portions of the core • • indicates that only the red sediments retain stable • • magnetizations. The possibility exists that the Charles I • • • Formation has suffered pervasive remagnetization during Permian time.
Load more

Recommended publications
  • AND GEOLOGY of the SURROUNDING AREA I
    . " ... , - .: ~... GP3/10 ~ " . :6',;, J .~~- -i-~ .. '~ MANITOBA MINES BRANCH DEPARTMENT OF MfNES AND NATURAL RESOURCES LAKE ST. MARTIN CRYPTO~EXPLOSION CRATER .. AND GEOLOGY OF THE SURROUNDING AREA i . , - by H. R. McCabe and B. B. Bannatyne Geological Paper 3/70 Winnipeg 1970 Electronic Capture, 2011 The PDF file from which this document was printed was generated by scanning an original copy of the publication. Because the capture method used was 'Searchable Image (Exact)', it was not possible to proofread the resulting file to remove errors resulting from the capture process. Users should therefore verify critical information in an original copy of the publication. (i) GP3/10 MANITOBA M]NES BRANCH DEPARTMENT OF MINES AND NATURAL RESOURCES LAKE ST. MARTIN CRYPTO·EXPLOSION CRATER AND GEOLOGY OF THE SURROUNDING AREA by H. R. McCabe and B. B. Bannatync • Geological Paper 3/70 Winnipeg 1970 (ii) TABLE OF CONTENTS Page Introduction' r Previous work I .. Present work 2 Purpose 4 Acknowledgcmcnts 4 Part A - Regional geology and structural setting 4 Post-Silurian paleogeography 10 Post-crater structure 11 Uthology 11 Precambrian rocks 12 Winnipeg Fomlation 13 Red River Fomlation 14 Stony Mountain Formation 15 Gunn Member 15 Gunton Member 16 Stoncwall Formation 16 Interlake Group 16 Summary 17 Part B - Lake St. Martin crypto-explosion crater 33 St. Martin series 33 Shock metamorphism 33 Quartz 33 Feldspar 35 Biotite 35 Amphibole 36 Pseudotachylyte 36 Altered gneiss 37 Carbonate breccias 41 Polymict breccias 43 Aphanitic igneous rocks - trachyandcsitc 47 Post·crater Red Beds and Evaporites (Amaranth Formation?) 50 Red Bed Member 50 Evaporite Member 52 Age of Red Bed·Evaporite sequence 53 Selected References 67 .
    [Show full text]
  • Mannville Group of Saskatchewan
    Saskatchewan Report 223 Industry and Resources Saskatchewan Geological Survey Jura-Cretaceous Success Formation and Lower Cretaceous Mannville Group of Saskatchewan J.E. Christopher 2003 19 48 Printed under the authority of the Minister of Industry and Resources Although the Department of Industry and Resources has exercised all reasonable care in the compilation, interpretation, and production of this report, it is not possible to ensure total accuracy, and all persons who rely on the information contained herein do so at their own risk. The Department of Industry and Resources and the Government of Saskatchewan do not accept liability for any errors, omissions or inaccuracies that may be included in, or derived from, this report. Cover: Clearwater River Valley at Contact Rapids (1.5 km south of latitude 56º45'; latitude 109º30'), Saskatchewan. View towards the north. Scarp of Middle Devonian Methy dolomite at right. Dolomite underlies the Lower Cretaceous McMurray Formation outcrops recessed in the valley walls. Photo by J.E. Christopher. Additional copies of this digital report may be obtained by contacting: Saskatchewan Industry and Resources Publications 2101 Scarth Street, 3rd floor Regina, SK S4P 3V7 (306) 787-2528 FAX: (306) 787-2527 E-mail: [email protected] Recommended Citation: Christopher, J.E. (2003): Jura-Cretaceous Success Formation and Lower Cretaceous Mannville Group of Saskatchewan; Sask. Industry and Resources, Report 223, CD-ROM. Editors: C.F. Gilboy C.T. Harper D.F. Paterson RnD Technical Production: E.H. Nickel M.E. Opseth Production Editor: C.L. Brown Saskatchewan Industry and Resources ii Report 223 Foreword This report, the first on CD to be released by the Petroleum Geology Branch, describes the geology of the Success Formation and the Mannville Group wherever these units are present in Saskatchewan.
    [Show full text]
  • Subsurface Characterisation and Geological Monitoring of the CO2 Injection Operation at Weyburn, Saskatchewan, Canada
    Subsurface characterisation and geological monitoring of the CO2 injection operation at Weyburn, Saskatchewan, Canada JAMES B. RIDING & CHRISTOPHER A. ROCHELLE British Geological Survey, Keyworth, Nottingham NG12 5GG, UK (e-mail: [email protected]; [email protected]) Abstract: The IEA Weyburn Carbon Dioxide (CO2) Monitoring and Storage Project analysed the effects of a miscible CO2 flood into a Lower Carboniferous carbonate reservoir rock at an onshore Canadian oilfield. Anthropogenic CO2 is being injected as part of a commercial enhanced oil recovery operation. Much of the research performed in Europe as part of an international monitoring project was aimed at analysing the long-term migration pathways of CO2 and the effects of CO2 on the hydrochemical and mineralogical properties of the reservoir rock. The pre-CO2 injection hydrochemical, hydrogeological and petrographical conditions in the reservoir were investigated in order to recognise changes caused by the CO2 flood and to assess the long-term fate of the injected CO2. The Lower Carboniferous (Mississippian) aquifer has a salinity gradient in the Weyburn area, where flows are oriented southwest-northeast. Hydrogeological modelling indicates that dissolved CO2 would migrate from Weyburn in an east-northeast direction at a rate of about 0.2 m/year under the influence of regional groundwater flow. The baseline gas fluxes and CO2 concentrations in groundwater were also investigated. The gas dissolved in the reservoir waters allowed potential transport pathways to be identified. Analysis of reservoir fluids proved that dissolved CO2 and methane (CH4) increased significantly in the injection area between 2002 and 2003. Most of the injected CO2 exists in a supercritical state, lesser amounts are trapped in solution and there is little apparent mineral trapping.
    [Show full text]
  • Red River Carbonates (Saskatchewan): Major Facies, Lithological, and Spatial Controls on Rock Magnetism – Preliminary Observations
    Red River Carbonates (Saskatchewan): Major Facies, Lithological, and Spatial Controls on Rock Magnetism – Preliminary Observations Erika Szabo 1 and Maria T. Cioppa 2 Szabo, E. and Cioppa, M.T. (2003): Red River carbonates (Saskatchewan): Major facies, lithological, and spatial controls on rock magnetism – preliminary observations; in Summary of Investigations 2003, Volume 1, Saskatchewan Geological Survey, Sask. Industry Resources, Misc. Rep. 2003-4.1, CD-ROM, Paper A-2, 9p. Abstract Preliminary results from ten wells in the Saskatchewan portion of the Williston Basin reveal significant lithological, facies, and spatial controls on the natural remanent magnetization (NRM) intensity in Red River carbonates. High NRM intensity values are recorded within the limestone sequences, intermediate values are seen in burrowed/fossiliferous dolostone, and the lowest values of NRM intensity are measured in laminated/bedded dolostones associated with anhydrite. The NRM intensity tends to increase towards the centre of the Williston Basin suggesting that the most probable variables affecting NRM intensities are: 1) depth of sampling and 2) proximity to the North American Central Plains Conductivity Anomaly. With a few exceptions, the magnetite grain-size distribution determined from partial anhysteretic remanent magnetization (pARM) spectra seems to be unaffected by facies and other lithological variations, or by spatial position. Well 0210, in the northwestern part of the Williston Basin, however, has magnetite grain-size values that are predominantly in the pseudosingle domain range whereas samples from the other wells display a mixed pseudosingle and single domain grain-size distribution. These findings suggest that fluid flow from the Alberta Basin may have influenced this portion of the Williston Basin.
    [Show full text]
  • Index to the Geologic Names of North America
    Index to the Geologic Names of North America GEOLOGICAL SURVEY BULLETIN 1056-B Index to the Geologic Names of North America By DRUID WILSON, GRACE C. KEROHER, and BLANCHE E. HANSEN GEOLOGIC NAMES OF NORTH AMERICA GEOLOGICAL SURVEY BULLETIN 10S6-B Geologic names arranged by age and by area containing type locality. Includes names in Greenland, the West Indies, the Pacific Island possessions of the United States, and the Trust Territory of the Pacific Islands UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1959 UNITED STATES DEPARTMENT OF THE INTERIOR FRED A. SEATON, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington 25, D.G. - Price 60 cents (paper cover) CONTENTS Page Major stratigraphic and time divisions in use by the U.S. Geological Survey._ iv Introduction______________________________________ 407 Acknowledgments. _--__ _______ _________________________________ 410 Bibliography________________________________________________ 410 Symbols___________________________________ 413 Geologic time and time-stratigraphic (time-rock) units________________ 415 Time terms of nongeographic origin_______________________-______ 415 Cenozoic_________________________________________________ 415 Pleistocene (glacial)______________________________________ 415 Cenozoic (marine)_______________________________________ 418 Eastern North America_______________________________ 418 Western North America__-__-_____----------__-----____ 419 Cenozoic (continental)___________________________________
    [Show full text]
  • Contemporaneous Alteration of Lower Watrous Clastics and the Sub-Unconformity Alteration Zone in Southeastern Saskatchewan: Petrographic and Geochemical Evidence
    Contemporaneous Alteration of Lower Watrous Clastics and the Sub-Unconformity Alteration Zone in Southeastern Saskatchewan: Petrographic and Geochemical Evidence Gemma S. Bates 1, Alan C. Kendall 1, and Ian L. Millar 2 Bates, G.S., Kendall, A.C., and Millar, I.L. (2007): Contemporaneous alteration of Lower Watrous clastics and the sub- unconformity alteration zone in southeastern Saskatchewan: petrographic and geochemical evidence: in Summary of Investigations 2007, Volume 1, Saskatchewan Geological Survey, Sask. Industry Resources, Misc. Rep. 2007-4.1, CD-ROM, Paper A-7, 10p. Abstract Debate regarding the origin and timing of formation of a diagenetically altered zone underlying the sub-Mesozoic unconformity in southeastern Saskatchewan has been ongoing since its discovery in the mid-1950s. This alteration zone forms a regionally extensive caprock to numerous hydrocarbon pools within the area, as porosity and permeability have been occluded by pervasive dolomitization and void-filling anhydrite. Unconformably overlying this alteration zone are redbeds of the Watrous Formation, consisting of red-brown argillaceous siltstones and anhydritic mudstones, generally with a dolomitic cement. Locally, the Watrous redbeds are bound by primary calcite cement and the subjacent alteration zone is absent. The lack of this caprock seal often allows hydrocarbon migration into the overlying basal Watrous, resulting in the reduction of the redbeds to green strata. We use the genetic link between the absence of the alteration zone and dolomitic cement of the Watrous, alongside the relationship between the thickness and extent of the Watrous Formation and alteration zone, to propose a genetic link between the regional presence of the dolomitized zone beneath the unconformity and the dolomitic cement of the immediately overlying redbeds.
    [Show full text]
  • Lexicon of Bedrock Stratigraphic Names of North Dakota Joanne Van Ornum Groenewold University of North Dakota
    University of North Dakota UND Scholarly Commons Theses and Dissertations Theses, Dissertations, and Senior Projects 1979 Lexicon of bedrock stratigraphic names of North Dakota Joanne Van Ornum Groenewold University of North Dakota Follow this and additional works at: https://commons.und.edu/theses Part of the Geology Commons Recommended Citation Groenewold, Joanne Van Ornum, "Lexicon of bedrock stratigraphic names of North Dakota" (1979). Theses and Dissertations. 111. https://commons.und.edu/theses/111 This Thesis is brought to you for free and open access by the Theses, Dissertations, and Senior Projects at UND Scholarly Commons. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of UND Scholarly Commons. For more information, please contact [email protected]. , I LEXICON OF BEDROCK STRATIGRAPHIC NAMES OF NORTH DAKOTA by Joanne Van Ornum Groenewold Bachelor of Science, University of North Dakota, 1971 A Thesis Submitted to the Graduate Faculty of the I University of North Dakota in partial fulfillment of the requirements for the degree of I Master of Science It GEOLOGY LIBRARY j U1i,erslty ,t Nert• B1k1t1 i Grand Forks, North Dakota !: May r' i 1979 This thesis submitted by Joanna Van Ornum Groenewold in partial fulfillment of the requirements for the Degree of Master of Science from the University of North Dakota is hereby approved by the Faculty Advisory Committee under whom the work has been done. (Chairman) ) . This thesis meets the st,ndards for appearance and conforms to the style and format requirements of the Graduate School of the Univer­ sity of North Dakota, and is hereby approved.
    [Show full text]
  • The Red Jacket Formation of Southeastern Saskatchewan
    The Red Jacket Formation of Southeastern Saskatchewan L.K. Kreis Kreis, L.K. (1988): The Red Jacket Formation of southeastern Saskatchewan; in Summary of Investigations 1988, Saskatchewan Geological Survey; Saskatchewan Energy and Mines, Miscellaneous Report 88-4. This report describes a proposed redefinition of part of and upper member of the Gravelbourg Formation. The the Jurassic stratigraphy in southeastern Saskatchewan. Red Jacket Formation is named after a village near the The need for a redefinition has arisen because of difficul­ type section of the formation in the Tide Water North ties in attempting to extend stratigraphic picks of the Wapella Crown 14-22-15-1 (Lsd. 14-22-15-1W2M) well. Shaunavon Formation and upper member of the Gravel· bourg Formation from their type area in southwestern Included in this report is a description and discussion of Saskatchewan into southeastern Saskatchewan. the type section, as welt as the boundaries, distribution, lithology, age and correlation of the Red Jacket Forma­ In an attempt to redress these difficulties and in conform­ tion. A west to east cross-section showing correlation of ity with the North American Stratigraphic Code Jurassic strata between southwestern and southeastern (American Association of Petroleum Geologists, 1983, Saskatchewan is included in the accompanying map Article 23, Remark b), the author proposes the estab­ package. A description of core from the type section is lishment of a new stratigraphic unit in the southeast, the given in the Apppendix. This work is part of a broader Red Jacket Formation, which is separated by an ar­ study by the author of the oil-bearing Jurassic sand­ bitrary lithofacies cut-off from the Shaunavon Formation stones occurring at various levels in the Wapella - Moosomin area (Figure 2 and cross-sec­ T W NOR lH WAPELLA CR 14 22 15 1 tion in map package).
    [Show full text]
  • Mapping of Salt Dissolution Edge of Prairie Evaporite in South-Central Saskatchewan
    Mapping of Salt Dissolution Edge of Prairie Evaporite in South- Central Saskatchewan Hamid,H., Morozov I.B. Department of Geological Sciences, University of Saskatchewan, Kreis, K. Saskatchewan Industry and Resources Summary Salt of the middle Devonian Prairie Evaporite Formation extends over much of the south-central Saskatchewan. Prairie salt collpases are among major stractural disturbances of the phanerozoic strata. The present stuady focuses on improving the delineation of the salt dissolution edge along the southeastren margin of Prairie Evaporite using 2D seismic data aquried by the industry. Thirteen seismic lines were re-processed with an emphasis on improvement of high-frieuency recovery that would allow detection of thin beds and salt edges of the Prairie Evaporite. Interpreted seismic sections show that salt collapse could be located off salt where salt have been dissolved and removed completely. They also could exist within the body of Prairie Evaporite. High-frequency seismic data display marked improvement in the accuracy and in the quality of the mapping of salt edge of the Prairie Evaporite. In a collocated gravity study, a 33 km NE gravity profile along seismic line NOR-83314 was modeled using GM-SYS software. A detailed two dimensional gravity model was costructed using well and seismic data. Although the ~4 mgal gravity anomaly is mainly related to the lateral variation of the basement rocks, the effect of the phanerozoic has been noticed. Based on the interpretation of seismic line NOR-83314, the thickness of Prairie Evaporite Formation is 60 m, leading to ~0.4 mgal contribution to the garvity anomaly. Performing high-resolution gravity survey with station interval ~100 m might still be useful to constrain the overburden and help detect salt collapses.
    [Show full text]
  • Mississippian Madison Formation Low-Gravity Oilfields in Southwestern Saskatchewan: Exam Pies of Unconformity Diagenesis Controlling Reservoir Quality
    Mississippian Madison Formation Low-gravity Oilfields in Southwestern Saskatchewan: Exam pies of Unconformity Diagenesis Controlling Reservoir Quality D.M Kent I and L.K. Kreis Kent, D.M. and Kreis, L.K. (2001): Mississippian Madison Formation low-gravity oilfields in southwestern Saskatchewan: Examples of unconformity diagenesis controlling reservoir quality; in Summary of Investigations 200 I, Volume I, Saskatchewan Geological Survey, Sask. Energy Mines, Misc. Rep. 2001-4.1. 1. Introduction Saskatchewan. They provide additional information which gives new insights into the geology of the area. The Mississippian rocks of southwestern Saskatchewan, unlike their counterparts on the eastern The localities of interest in this paper all lie within flank of the Williston Basin, have yielded exclusively Townships 1 to 6 and Ranges 22 to 30 west of the low-gravity oil shows in cores, drill cuttings, and Third Meridian. The five producing localities, Battle drillstem tests since the early days of exploration in Creek, Battle Creek West, Divide, Rangeview, and both southeastern Alberta and southwestern Rangeview East have a total of 27 vertical and Saskatchewan. However, the potential of the rocks for directionally drilled wells and six horizontals that have commercial oil production has commonly been produced or are producing low-gravity oil from the overlooked because of the extremely low APJ ( 11 ° to Madison. Twenty-three of the wells are classified as 13°) in Mississippian core and drillstem tests. Twenty­ suspended or plugged back. The majority of these are four of these oil shows were identified from the area in the area encompassing Rangeview, Rangeview East, bounded by Range 20 west of the Third Meridian, the and Divide.
    [Show full text]
  • Stratigraphy and Petroleum Production Potential of the Spearfish Formation in North Central North Dakota Nnaemeka C
    University of North Dakota UND Scholarly Commons Theses and Dissertations Theses, Dissertations, and Senior Projects 2011 Stratigraphy and Petroleum Production potential of the Spearfish Formation in North Central North Dakota Nnaemeka C. Anyanwu University of North Dakota Follow this and additional works at: https://commons.und.edu/theses Part of the Geology Commons Recommended Citation Anyanwu, Nnaemeka C., "Stratigraphy and Petroleum Production potential of the Spearfish Formation in North Central North Dakota" (2011). Theses and Dissertations. 6. https://commons.und.edu/theses/6 This Thesis is brought to you for free and open access by the Theses, Dissertations, and Senior Projects at UND Scholarly Commons. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of UND Scholarly Commons. For more information, please contact [email protected]. ,I STRATIGRAPHY AND PETROLEUM PRODUCTION POTENTIAL OF THE SPEARFISH FORMATION IN NORTH CENTRAL NORTH DAKOTA by Nnaemeka C. Anyanwu Bachelor of Science; Federal University of Technology Nigeria, 2006 A Thesis Submitted to the Graduate Faculty of the University of North Dakota in partial fulfillment of the requirements for the degree of Master of Science Grand Forks, North Dakota December 2011 1 ~ i This thesis, submitted by Nnaemeka C. Anyanwu in partial fulfillment of the requirements for the Degree of Master of Science from the University of North Dakota, has been read by the Faculty Advisory Committee under whom the work has been done and is hereby approved. · 1 (Chairperson) ~~~~(J--- J This thesis meets the standards for appearance, conforms to the style and format requirements of the Graduate School of the University of North Dakota, and is hereby approved .
    [Show full text]
  • The Spearfish Formation – Another Unconventional Target Julie A
    The Spearfish Formation – Another Unconventional Target Julie A. LeFever The production history from the Spearfish Formation (Triassic) in the state is similar to the drilling history of the Bakken Formation and other unconventional reservoirs. Drilling in Bottineau County began with a random wildcat, the Zach Brooks Drilling Company - #1 Edwin Berentson (SW¼ SE¼, Sec. 21, T163N, R79W). Drilled and completed in November 1952, this well was the first commercial oil well in Bottineau County and the discovery well for Westhope Field. Early wells in the county produced primarily from the Madison Group (Mississippian) but strong oil shows in the overlying Spearfish Formation suggested that it might also be a target. Subsequent discoveries at Newburg (1955) and South Westhope (1956) fields proved this to be true (fig. 1). Drilling activity reached record highs from 1957 to 1959 and continued through 1961 in the region as companies actively pursued the Madison Group and Spearfish Formation (LeFever and LeFever, 1991). A number of new fields were added at this time (fig. 1). It is interesting to note that marketing the oil in this area was difficult early in the exploration history of the region. Prior to 1963, production in the north-central portion of the basin was marketed by rail until 1963 when the Portal Pipeline was constructed to carry crude to refineries in Minnesota and Figure 2. Outcrop photograph of red siltstones, sandstone, and mudstones of the Spearfish Formation taken in the town of Spearfish, South Dakota (wild turkeys for scale). Wisconsin (Gerhard et al., 1982). A successful waterflood was initiated by Amerada Petroleum Corporation in 1967 to reverse the gradual decline of production in Newburg Field.
    [Show full text]