GEOLOGICAL DEVELOPMENT, ORIGIN, AND ENERGY MINERAL RESOURCES OF THE WILLISTON BASIN, NORTH DAKOTA
by
LEE C. GERHARD, SIDNEY B. ANDERSON, JULIE A. LEFEVER, and CLARENCE G. CARLSON
MISCELLANEOUS SERIES 63 Reprinted from The American Association of Petroleum Geologists Bulletin No.8, v. 66 NORTH DAKOTA GEOLOGICAL SURVEY (AugllSt. 1982), p. 989-1020. 36 Figs., 1 Table. Don L. Halvorson, State Geologist The American Asso~iation of Petroleum Geologists Bulletin v. 66, No.8 (Auguu 1982), P. 989-1020, 36 Figs., I Table
Geological Development, Origin, and Energy Mineral Resources of Williston Basin, North Dakota}
LEE C. GERHARD,' SIDNEY B. ANDERSON,' JULIE A. LEFEVER,> and CLARENCE G. CARLSON'
ABSTRACT part of the basin during Absaroka sequence deposition, a product oferosion ofAncestral Rocky Mountain orogenic The Williston basin of North Dakota, Montana, South structures. Continental and shallow marine clastic sedi Dakota, aud south-ceutral Canada (Manitoba and Sas ments were deposited during Zuni sedimentation until katchewan) is a major producer of oil and gas, lignite, Cretaceous deeper marine environments were estab and potash. Located on the western periphery of the lished. Laramide orogenesis to the west provided detritus Phauerozoic North American craton, the Williston basin that was deposited in Ouvial, deltaic, and marginal has undergone only relatively mild tectonic distortion marine environments, regressing to the east. Major lig during Phanerozoic time. This distortion is largely re nite deposits are part of this postorogenic regressive rock lated to movement of Preca mbrian basement blocks. body. Sedimentary rocks ofcratonic sequences Sauk through Major structures in the basin, and the basin itself, may Tejas are present in the basin. Sauk (Cambrian-Lower result from left-lateral shear along the Colorado Ordovician), Tippecanoe (Ordovician-Silurian), and Wyoming and Fromberg zones during pre-Phanerozoic Kaskaskia (Devonian-Mississippian) sequence rocks are time. Deeper drilling in the basin has revealed several largely carhonate, as are the major oil- and gas major structures and given indications of others. Most producing formations. Absaroka (Pennsylvanian structures probably resulted from renewed movement or Triassic) and Zuni (Jurassic-Tertiary) rocks have more "tensing" of pre-Phaneroroic faults. Meteorite impact clastic content, but carbonates are locally important. events have been suggested as the origin for one or more Clastics of the Zuni sequence (Fort Vnion Group) contain structures. abundant lignite. Tejas (Tertiary-Quaternary) sequence rocks are not significant in the production of minerals or INTRODUCTION energy, although glacial sediments cover much of the region. Recent successful oil exploration and development in the Oil exploration and development in the Vnited States Williston basin have clearly demonstrated the inadequacy of portion of the Williston basin since 1972 have given im previous tectonic and sedimentologic models of the basin to petus to restudy basin evolution and geologic controls for predict occurrences of mineral and fuel resources. The energy-resource locations. Consequently, oil production in North Dakota, for instance, has jumped from a nadir United States portion of the basin has sustained oil develop ofl9 million bbl in 1974 (compared to a previous zenith of ment during the last half of the 1970s that is remarkable in its 27 million in 1966) to 32 million hbl in 1979 and 40 million definition of previously unrecognized structures, discovery bbl in 1980. Geologic knowledge of carbonate reservoirs of new producing zones, and high success rates. The largest has expanded accordingly. single segment of the basin is the North Dakota portion (Fig. Depositional environments throughout Sauk, Tip I), which includes the deepest part of the basin and the pecanoe, and Kaskaskia deposition were largely shallow thickest Phanerozoic section. The wildcat success rate in marine. Subtidal and even basinal environments were North Dakota has steadily increased from 250/, in 1977; 28% developed in the basin center, but sabkha deposits were in 1978; 33% in 1979; to 36% through the first 6 months of abundant near the basin periphery. Evidence ofsubaerial 1980, whereas the recent national average was 15 to 18% for a weathering was commonly preserved in structurally high areas and on the basin periphery, especially in upper similar period (Johnston, 1980; Fig. 2). Although South Kaskaskia rocks. Some pinnacle reefs were developed in Dakota and Montana also sustain active programs, their Kaskaskia deposition. morphologically similar to the success rates are lower; Montana has the second most suc Silurian pinnacle reefs of the Michigan basin. cessful active drilling program in the basin. Clastic sediments were transported into the southern Oil and gas are not the only mineral and energy resources
@1982. The Amencan ASSOCiation of Petroleum Geologists All nghts Ing our efforts. In particular. James H. Clement of Shell Oil Co.; Cooper reserved. Land, consultant; and Walter Moore of the University of North Dakota have 'Manuscnpt received, July 10, 1981, revised and accepted, Apn114, 1982. been Instrumental in construction of our ideas and approach. Other col 2North Dakota Geological Survey. Present address Union Texas Petro leagues and students who have contributed to this summary are Randolph leum Company, Denver, Colorado Burke. Diane Catt, Tom Heck, John Himebaugh. Peter Loeffler, Tom 3North Dakota Geological Survey, University Station, Grand Forks, North Obelenus, and Nancy Perrin. Support for some of the original studies of Dakota 58202. depositional systems and reservOIr geology came from the North Dakota 4North Dakota Geological Survey. Present address: OIl and Gas DiVISion, Geological Survey, the Carbonate Studies Laboratory of the University of North Dakota Industrial Commission, Bismarck. North DaKota. North Dakota, and from a grant by the U.S. Geological Survey (14-08· Many of our colleagues, students, and cooperating SCIentists have spent 0001-G-591). All of the support is gratefully acknowledged. extensive amounts of time discussing ideas. providing data. and redirect-
989 990 Williston Basin, North Dakota of the basin. Lignite reserves are huge and are actively being basin penetrated Precambrian rock at l5,340 ft (4,676 m); the explored and utilized. Rich potash resources are being mined deepest oil production is from 14,343 ft (4,372 m) in the in Saskatchewan and a mine has been announced for western Ordovician Red River Formation (Mesa 1-13 Brandvik, Dunn Manitoba. In North Dakota and Montana, potash resources County, Nonh Dakota). are potentially far more valuable than the lignite, but are not Rocks deposited during all periods of Phanerozoic time are yet being mined. Halite is being mined near Williston, North present in the basin (Fig. 3). Paleozoic rocks are mainly Dakota, from depths of 8,000 ft (2.438 m) making it proba carbonates, followed by the dominantly clastic Mesozoic and bly the world's deepest salt production. The halite deposits Cenozoic rock sequence. Sloss's (1963) sequence concept is are vast, being approximately 1,700 mi' (7,086 km'). particularly useful in the study of these rocks. serving to Coincident with energy development, interest in water "package" major transgressive cycles of continental scale resources (for energy transportation) and the overall regional with accompanying sediment deposition. For this reason, economic significance of the basin has led to an extensive discussions of stratigraphic units and their significance to study of basin geology, with numerous programs of investi deciphering the structural evolution of the Williston basin are gation under way. Programs of the Nonh Dakota Geological organized by sequences. Survey, the U.S. Geological Survey, Depanment of Energy, Few regional studies of Williston basin rocks have been and several oil companies deserve particular note; much of published. Several important contributions used extensively the information in this summary is derived from these in this paper are the papers of Poner and Fuller (1959), sources. Carlson and Anderson (1966), the various papers presented in The Williston basin is a slightly irregular, round depression the Geologic Atlas of the Rocky Mountains (Mallory, 1972 a, in the western distal Canadian shield. Structural trends within b), and Macauley et al (1964). Several unpuhlished works of the basin reflect major directional changes in the structure of oil company geologists are also used in this paper, especially the Rocky Mountain belt (Fig. 2). Several writers have those of lames Clement (personal commun., oral dis hypothesized a wrench-fault system for control of basin cussions, 1975-80). geometry and structure (Thomas, 1974: Brown, 1978), al Several cycles of interpretive writing are evident in the though those studies did not integrate sedimentary depo· literature about the Williston basin. Each proceeds from an sitional facies and porosity development infonnation. equivalent cycle ofmineral or fuel development activity. This Approximately 16,000 ft (4,875 m) of sedimentary rocks cycling of activities is common to most petroleum provinces. are present in the deepest part of the Williston basin, south The Williston basin is in its third cycle of oil development east of Watford City, Nonh Dakota. The deepest well in the now and is rapidly increasing oil production. Most of the United States pan of the Williston basin is contained in Nonh Dakota; its statistics are impressive. After reaching a high of
"~--., ------,..--...,TO'. 27 million bbl ofoil produced in 1966, production declined to I '. I USUTt~(."''' I 19.5 million bbJ in 1974. During the third cycle of develop I ;::.;;". --- .I I --->: I ., \ ment, production began to increase in ]975, reaching a new I "··t I • C...... D'..... I ... I II • • \ s"'HD .. '- I historic high of 32 million bbl in 1979, increasing to 40 , '. I \. I million bbl for 1980. Concurrent with this cycle of develop I I ". I ~,..~t!t- I ment. research into oil and gas reservoir geology, regional 1 I •.•. ' .~:S" I I I', I <;''-?t- I ,•.• :...o~ I depositional systems, and other aspects of basin analysis has \... I .. 1\ tr~~:" /1 been revived with applications of technology developed 'I I \.;"" ( since the mid-1960s. Summary papers of this era are included ..., , t/~ \ in Estelle and Miller (1978) and in several publications of the '"\ I ~'% \ '\ I ul'" \ Nonh Dakota Geological Survey (Bjorlie, 1979; Carroll, \ C"LUU ;''' ''' ~ \. , - ... _ 1\ \ 1979: Bluemle et ai, 1980; Scott, 1981: Lerud, 1982). Various " I ( ...... I \ 1 : I 'UG'":''' ,\ • \ orally presented papers at national and regional society tech ~ • I .,U,STOll "\ .,....,Pl$ \ 1- -L-~~--- 1...... ~ ... _ ~- nical programs also added ideas and data to the present I..O.iT.... \, --- -'-r -\- .~, I exploration cycle. USI.. "',\ I \ \ \ ~ \ \\ The purpose of this paper is to summarize briefly the ' " \ I I , 1 I current knowledge of the geologic evolution and energy I '- , I e,s",.. ItCIl '.,OIlT" \ - I \./.~~D~·_1 resources of the North Dakota ponion of the Williston basin. ''I B'LL"." r- sou... ' ( As in any summary paper, this effort is colored by the geolog " I ~ DUDT.. \; ..... ~ i;y"(;"'Pti------"\. ' \.' ical philosophies and biases of the writers. , I _ P'll(l( ~ I , f TECTONIC SETTING N :------""'\ I I The Canadian shield extends under the Williston basin to '""= ='00 100 ""~tt the Cordilleran geosyncline. The Williston basin forms a '00 () '00 zoo '00 Il'Ll»IlTUs large depression in the western edge of the shield, occupying much of North Dakota, nonhwestern South Dakota, the FIG. I-Index map showing location of Williston basin in eastern quarter of Montana, a significant part of southern United States and Canada. Modified from Worsley and Fuzesy Saskatchewan, and a portion ofsouthwestern Manitoba. This (1978). part ofthe craton is bordered on the south by the Sioux arch, Lee C. Gerhard el al 991 on the southwest by the Black Hills uplift and Miles City Churchill provinces of the Canadian shield. Stratigraphic and arch, and on the west by the Bowdoin dome (Fig. 2). gravity studies suggest that this boundary is an important Structural grain of the region appears to be related to the factor in Phanerozoic basin development. offset in the Rocky Mountain chain between the north Structural trends within the Williston basin reflect both the trending southern Rocky Mountain province and the north- and northwest-trending grain of the Rocky Mountain northwest-trending northern Rockies indicated by propri province. The Cedar Creek and Antelope anticlines are etary seismic data. The zone of offset in Wyoming and northwest-trending structures: the Poplar anticline is slightly Montana (centra] Rockies) is characterized by northwest divergent from the~ but is also generally northwest trending. structural grain of basin and range configuration. Regional The Nesson, Billings, and Little Knife anticlines are north wrench faulting along the Cat Creek and Lake Basin zones trending structures. An additional northwest-trending struc (Thomas, 1974) suggests to us that structural control of the ture, which is an extension of the Antelope anticline in the Williston basin is related to large-scale "tears" in the edge of southeast part of the basin, has been mapped in the course of the craton. preparation of this paper (Bismarck-Williston zone). Ballard (]963) outlined a hinge line for the eastern part of Several smaller structures on the eastern shelf have been the Williston basin in central North Dakota (see also Laird, mapped by Ballard (1963); those in Foster and Stutsman 1964), which is the boundary between the Superior and Counties are probably important. The Cavalier high (Ander , ,i>.;. 10.· I~" '~ , ___ ~_;;I;"______~1'-' MA~ToeA F------..",,,, SASKATCHEWAN NfwPORTE ----rP/------ ~-<; ~ STRUCTURE I~ ~O I.,,+"'V I I>0 ~ciN~R I \Il: NESSON ~I 0::0 I rTiCLINE ZI ;;: ANTELOPE > W I WATFORD I ANTICUNE § '5 I DEEP \ :Ell/)~ '" 1 'RED WING ···.6, j--"'\ FOSTER HIGHll UJ CREEK STRUCTURE ";S'4f d\ j Iz '.;.q~ x: o ~_ +c ITnE '.~ u ~Id I KNIFE (f~e:'~."'1. ~\ r ~ STUTSMAN HlGH C"- "?¢'0 ;;;:;..... iH I> I 4~r1CI.INf 1 ..." If ~IO B .• o ::I: (LLINGS . I 'f., SHEEP" I AN'l"TtLINE ~"""' ...\1 '1;, MOUNTAIN ~\ SYNCLINE \ \• ., I 1 I .MILES I U CITY \ \ ~I1CRrnr ______---l.. NORTI1 OAKOTA I B"SI~ ANTICLINE ------ 4.·. LAI(E FAULT ZOf.JE 1 1 I 1 1 M~~~ I t : -_. I .PIERRE 'i---: === I ~"-".. sc.u i
WYOMING SOUTH OAKOTA , , ,~.. l1 'w, , 'i"'. FIG. 2-Major structures of Williston basin based on current subsurface structural mapping and geophysical interpreta tions. 992 Williston Basin, North Dakota
tl MINNEKAHTA PERMIAN c ~ ~ OPECHE SYSTEMS ROCK UNITS 0 0 a:: .. c BROOM CREEK • CIl AMSDEN QUATERNARY •« PLEISTOCENE PENNSYLVANIAN III ~ c !" WHITE RIVER TYLER GOLDEN VALLEY OTTER KIBBEY TERTIARY FORT POPLAR INTERVAL UNION AATt'I.lFFE GROUP MISSI SSIPPIAN !' IN I CIl FR08ISHER 0 A~~~, c INT HELL CREEK 2 TILSTON FOX HILLS c BOTTINEAU CIl" INTERVAL PIERRE c CIl" c BAKKEN ~ JUDITH RIVER .:: THREE FORKS 5 CRETACEOUS z BIRDBEAR ::;) N EAGLE 11 - ~c! DUPEROW NIOBRARA SOURIS CARLILE DEVONIAN -- RIVER DMSON BAY GREENHORN ~ BELLE ;;5.. PRAIRIE FOURCHE ...... 2e-. WINNIPEGOSIS MOWRY NEWCASTLE ASHERN SKULL CREEK
INYAN KARA SILURIAN INTERLAKE ~ Z C u ------.j III STONEWALL A. SWIFT A. STONY NTN. JURASSIC ~ RIERDON ORDOVICIAN REO RIVER
PIPER WINNIPEG GROUP
TRIASSIC I CAMBR FIG. 3-Generalized stratigraphic column of Williston basin. Lee C. Gerhard ot al 993 son, 1974) is apparently a paleotopographic artifact of pre structurally assisted stratigraphic oil traps in north-central Mesozoic drainage (Fig. 4). North Dakota. Two other structural elements may be significant to basin Several writers have attempted to establish a wrench· fault interpretation: the Red Wing Creek structure and the New framework for the basin. Recently, Brown (1978) has used porte structure (Fig. 2). Both of these structures are enig isopach variations in individual stratigraphic units to build a matic. although the Red Wing Creek structure has been wrench-fault deformation fabric for the southern part of the described as an astrobleme (Brennan et ai, 1975; Parson et al. basin. Earlier, Thomas (1974) built a regional theoretical 1975). The Newporte structure is interpreted to be a faulted model for wrench·fault tectonics in the Montana and North block of early Paleozoic age in which oil has been trapped Dakota parts of the basin. along unconformities within Cambrian and Ordovician There is little question in our minds that sedimentation and sedimentary rocks; one well produced from Precambrian structure of the basin are controlled by movement of base· crystalline rocks (Clement and Mayhew, 1979). However, ment blocks that were structurally defined in pre-Phanerozoic the structure may be of meteorite origin (Donofrio, 1981). time. One of the earliest clear demonstrations of this is the Indications of other tectonic elements or theoretical proj work of Carlson (1960) showing Cambrian topographic relief ects of deformation have been published by several writers. on the Nesson anticline. Carroll (1979) illustrates the role of Keams and Traut (1979) illustrated satellite imagery surface Precambrian topography in Red River porosity development. lineations which are northwest and northeast trending; al The relative importance of wrench faulting, interprovince though northwest-trending structures are known to be of shearing, vertical-tensional defonnation, and continental significance in the basin, this is one ofthe few illustrations of boundary compression or tensional stress have not been the northeast trends that control much of the Mississippian evaluated for the tectonic framework of the basin. Studies of I ' --~- -~- .~---- -~ -- ~- - - - -~- -- ....a_ ~rc1&mlifli:i;~~5 ,f F~:;"-":\ L--. .- - ~= ----~_. ~.:.~~i~'.~'-~~~~~III~',r.~:~t.{:;;I~1 r: .''''C·''',,.•"j [s- I I '. .2tt~~~!1?~ -....:...... - ., V-j MINNEKAHTA , '. TYLER MOUNTAIN RIVER FIG, 4-Pre-Mesozoic paleogeologic map of North Dakota. Modified from Carlson and Anderson (1966). 994 Williston Basin, North Dakota depositional systems and mapping of structural changes The only faunal studies of the Deadwood in North Dakota through time are under way and should materially assist a are studies (Carlson, 1960) of conodonts from the upper part tectonic interpretation of basin history. of the Deadwood in the Nesson anticline area. The conodonts are probably of Early Ordovician age. Ross (957) also noted STRATIGRAPHY Early Ordovician fossils in cores from eastern Montana con firming that the Deadwood is of Late Cambrian through Early Sauk Sequence Ordovician age where the thicker sections are preserved. A (Cambrian-Lower Ordovician) regional disconfonnity separates Winnipeg and Deadwood rocks. Phanerozoic sedimentation was initiated in the Williston basin during latest Cambrian (Croix ian) time (Fig. 5), when Tippecanoe Sequence the margin of the early craton was transgressed from the west (Ordovician-Silurian) by shallow marine water. In all probability. the entire basin sustained upper Sauk clastic sedimentation (Deadwood For A second cycle of transgression, sedimentation, and re mation), The total thickness of Sauk sedimentary rocks in the gression comprises the Middle Ordovician through Silurian basin probably does not exceed 1,000 ft (305 m). Isopach rock record oflhe Williston basin. This cycle, the TIppecanoe maps by Carlson (1960) and Lochman-Balk (1972) demon sequence (Figs. 6, 7), marks the beginning of the Williston strate that the prescnt basin was simply a large embayment on basin as a discrete structural depression with marine connec the western Cordilleran shelf and was not structurally well tions to the southwest (Foster, 1972). Although the transgres defined. Apparently, there was a northwest slope into the sive phase (Winnipeg Fonnation) is clastic, including a western Canadian miogeosyncline (Porter and Fuller, 1959). well-developed basal sand, the sequence is largely carbon Transgression occurred over a highly irregular surface on ate. Isopach studies of the sequence and its individual rock Precambrian crystalline rocks (Carlson, 1960) Present data units suggest a southwesterly connection to the western indicate a hilly terrain with a few large topographic promi geosyncline through the present central Rockies. Whether nences, such as the Nesson anticline. Like most basal Sauk this is an artifact of late erosional events or not is unknown, units, the Deadwood is largely clastic, including much re Similarly, a marine connection existed across the Sioux arch worked, weathered Precambrian material. The middle of the to the eastern interior (Fuller, 1961, Fig. 21). Carroll (1979), Deadwood in western North Dakota contains appreciable in a study of tbe Red River Formation, clearly showed the limestone and limestone conglomerate, becoming more influence of the Nesson anticline block, Billings anticline, clastic as it thins eastward. the eastern North Dakota "highs," and several other struc- LOWIIR ~ ~:-~>~ QUlCIVICIAN ci: - ----. fllml ~ ~ DHDWOQD t,OOO (300) ,-. ~,.- ~.-.-, ~ ~sa ,•• ~-',' :~''-;' ,IJ,"', ~,~ A_ .. ,"_/.,_,;~~, ~=- 'CAMBRIAN', f---...::--_~ '" C=,.-_ - -I .~.~ ~ ;.~'", l. . ;"'~~ FIG. 5-Stratigraphic column of Sauk sequence. Modified from Bluemle et al (1980). Oil ~ ~ ft(m) l'nIU.\ld 0" 1.000 (335) ",III,'RIAN ~%~' ..::.::..---=-==---~-"--~ I I I J'~'2~~---~- I 1 >TO""" I 10B 120(lS) -~ .~ I -~ - qo\" l.l"'IO'" .~ 0; -::; 200 t60) ~ 'HH \'T'1\' qUI (,liTO' - '" "' ~ Oil "1(,1101{' 0" [*7,-·-.L.J__ r'-{"T'T.;I:..:: 700 (21S) KUllllHI{ ~-=i~_:J,~i 1\1 ,\. '\' lel/\,'\, ~<~~ ~~-c;-=;1/ 90 (30) RO! ('1I1~ ILUIU' ~- -~~--;~~~~ 145 (45) 'H"IP£(; I I:IL.\C.... ISU .. FIG. 6-Straligraphic column of Tippecanoe sequence. Modified from Bluemle et al (1980). Lee C. Gerhard et al 995 tures. Isopachs ofthis fonnation are particularly important in Sedimentation was continuous from the beginning of Red studying basin evolution because they have been unaffected River deposition through the Silurian. Roehl (1967) carefully by later erosional events except aJong the basin margin. documented the analogy between Silurian Interlake Forma Carbonate rocks ofthe Red River and Interlake Fonnations tion fabrics, structures. and geometry and modem Bahamian (Carroll, 1979; Roehl, 1967) were deposited under shallow tidal-flat features. Regression after Silurian deposition re marine and evaporite sabkha environments. Although the sulted in at least partial karst surface development. basin was well defined, there is little evidence of any particu larly deep basal sedimentation. The Red River Formation Kaskaskia Sequence contains shelf and lagoonal fabrics and biotas (Carroll, (Devonian-Mississippian) 1979), as well as sabkha evaporites and supratidal carbon ales. Porosity development in the Red River is partly con Kaskaskia sequence rocks are perhaps the best known of trolled by buried Precambrian hills or structures. D zone the sequences because of their economic importance and selective dolomitization of burrowed wackestones occur::; on because more subsurface data are available than for other the periphery of a buried "high" owing to density of groups. Thirteen studies of separate Kaskaskia rock units are dolomitlzing brines. Higher A, B, and C zone porosities are either completed or in progress by North Dakota Geological remnant after supratidal and/or sabkha dolomitization on the Survey and University of North Dakota geologists more crestal parts of highs (Table I, Fig. 8; Carroll, 1979; Limestones are the most characteristic lithology of the Carroll and Gerhard, 1979). sequence. but two episodes of evaporite deposition inter , , ,le· ,D." ". ,~ TIPPECANOE ISOPACH SASKATCHEWAN itT MOOIFIED FROM FOSTER AND GIBB,19721 ---1--~---7--l, MANITOBA -_-- --7-----7 ----, -- 1"'-'-' -TI- / / , / /"" ' I' \ /1 ) r) r \ f : l.../ I <'Gb \ \ o ""\ % ( \ " ) \ ,/ / .MILES / CfTY "'--... / / _(",-L __ - _.....--NORn~ nA.I(01"A. / ______.___"' o so ""LfS "= ""o,,-,-TOM '<'00. I(:AL[ CONlOY'" ItlolltlVAI. ~oo ,~~,. WYOMING ,- ,w 10.· 10l" FIG. 7-Isopach map of TIppeeanoe sequence in Williston basin, 996 Williston Basin, North Dakota T2f RED RIVER (a) ii/III/ill! "AI. 1;':7L~~3 POROUS ZONE SEQUENCE FIG. 8-(a) Porosity zones in Red River Formation. A, B, and I!//III;!III C zones have alternation of three lithologies: limestone, dolo "s" TL-T"-T~L mite, and anhydrite in ascending order. D zone porosity is -"--L73L£~ POROUS ZONE alternating limestone and dolomite. (b) Dolomitization model b;::" 2 c"'L; for A, B, and C zones by evaporation causing replacement of SEQUENCE primary carbonate muds. (c) Dolomitization model D zone, showing brine percolating down dip through primary bur rowed carbonate muds, but blocked by impervious organic carbonates from vertical movement. (d) Diagram showing !!! ji11/ how A, S, and C zone dolomite porosity occurs on top of buried structures. (e) Diagram showing D zone dolomite ,! ,II porosity occurring on flanks of buried structures. (0 Facies "e" distribution during deposition of A, B, and C zones, showing '" /T -"F:; POROUS ZONE supratidal dolomitization belt. (g) Facies distribution during _L-r deposition of D zone, showin~ pond and subtidal organic limestone deposited on top of lagoonal burrowed muds. All SEQUENCE diagrams modified from Carroll (1979) and Carroll and Ger~ hard, (1979). (Figure continued on next page). ALTERNATING "0 11 . .L.r;. POROUS/NONPOROUS ZONE BEDS ~ LOWER RED RIVER EVAPORATION (b) (c) ORGANIC :::; :!: .j;:4~'~ iH:-': ;':'1 I·i; I;' 'if.! ii,in iHi i Lee C. Gerhard et al 997 (e) ~ BURROWEO LIMESTONE ORGANIC BURROWED FIG. 8 (Conlinued). rupled the carbonate deposition (Devonian Prairie and Mis the Williston basin opened to the west through the Central sissippian Charles: Fig. 9). Winnipegosis carbonates trans Moncana trough (Bjorlie, 1979). Initial Mississippian Madi gressed an eroded surface of earlier Paleozoic rocks, repre~ son sedimentation (mid-Kaskaskia) was a mixture of near sented by red and gray shaly beds and carbonate breccias shore lagoonal clastics and apparent crinoidal mudmounds (Ashern). Winnipegosis sedimentation culminated in de (Waulsortian mounds) in central North Dakota and central velopment of large stromatoporoid banks and pinnacle reefs Montana (Bjorlie, 1979). before basin restriction increased salinity and induced Prairie Mississippian thicknesses, compared to Devonian in the evaporite deposition. Devonian seaways apparently opened basin, reflect the change of seaways, Activity in the Trans northward, and isopachs ofthe basin indicate a northward tilt continental arch may have been responsible for the Devonian to structures (Fig. 10); the high point of the Nesson anticline northward tilt. The Mississippian seaway may be related to shifts southward with the advent of Devonian sedimentation. development of shear systems in central Montana, Crustal The Dawson Bay and Souris River are not as well known as instability is suggested by angularity between successive other units, but appear to mark an initial influx of clastics and rock units of Upper Devonian and Lower Mississippian age supratidal carbonates over older deposits. along the eastern basin margin. Water deepened again during the time of Dawson Bay Kinderhookian sedimentation in the Mid-Continent is deposition, Carbonate buildups rich in stromatoporoids characterized by oolitic shelf carbonates. The Lodgepole ftourishedduring Duperow sedimentation (Hoganson, 1978). Fonnation in the Williston basin is no exception (Heck, Birdbear (Nisku) rocks are marine carbonates with shallow 1978). Upper Lodgepole rocks are concentric facies with shelf faunas; farther north these rocks are reefal. peripheral lagoonal beds and oolite banks, basinward pelletal Red and green siltstones and shales cover Birdbear car grainstones, and basin flank and basinal organic muds, bonates, marking a hiatus in the middle of the Kaskaskia Maximum transgression occurred near the end of sequence. These clastics are in tum overlain by initial trans Lodgepole or early in Mission Canyon deposition. Mission gressive deposits ofthe upper Kaskaskia - the Bakken Shale Canyon rocks are typically skeletal wackestones with shore (Upper Devonian to Lower Mississippian), a petroleum ward subaerial weathered fabrics and sabkha evaporites. source rock and producer. Some marginal evaporites fanned coeval with the weathered During the mid-Kaskaskia interval, a reorientation of sea· fabrics and are important lateral seals for stratigraphic oil ways occurred, so that during Mississippian sedimentation traps. 998 Williston Basin, North Dakota The carbonate-evaporite rocks are regressive, with evapo sedimentary rocks of the Rierdon and Swift Formations, rites climbing westward in the section (Fig. 11). Subaerial which also contain glauconitic sands and oolitic carbonate weathering of the skeletal wackestones has produced a va bars. riety of pisolitic and fenestrate fabrics which tonn important The top of the Jurassic is marked by a subaerial regressive oil reservoirs (Fig. 12; Gerhard et ai, 1978). exposure surface. It was followed first by terrestrial deposi Evaporite deposition in the Charles Formation (salt) con tion of the lower lnyan Kara Formation, then by the marine cluded Madison sedimentation. Sands, shales, and carbon transgressive phase of the upper Inyan Kara. ates were deposited in alternating restricted and normal Progressive deepening of the Western Interior Cretaceous marine environments during Big Snowy deposition at the seaway provided for the deposition of the remainder of the conclusion of the Kaskaskia sedimentary record. The extra Cretaceous marine section (Fig. 14). During deposition ofthe basinal clastic sediments mark the influence of the Ancestral upper part of the Pierre Shale, increasing amounts of sand Rocky Mountain orogenic event west and south of the indicate regression of the Cretaceous sea strandline and the Williston basin. beginning of formation of the clastic wedge derived from erosion of the Laramide Rockies. Absaroka Sequence Further uplift, erosion, and volcanism in the Laramide (Pennsylvanian-Triassic) Rockies provided extensive quantities of detritus to the Williston basin. In early Paleocene time, the last marine Regression during latest Mississippian time marked the setting in North Dakota was the site of deposition of the end of the last major Paleozoic marine sedimentation phase. Cannonball Formation. Later, Paleocene Fort Union sedi Orogenic events, including the Alleghenian, Ouachita, Ar ments covered and prograded over the Cannonball. Fluvial buckle, and Ancestral Rocky Mountain events, resulted in deltaic and paludal environments were characteristic of later cratonic uplift in the northern plains and Rocky Mountain Paleocene time during which extensive lignite deposits were region. Absaroka sedimentation is characterized generally by formed. Cyclical in nature, these deposits are one part of the interfingering of terrestrial clastic sediments with marginal combined Powder River and Williston basin detrital aprons marine and evaporite sediments (Fig. 13). Basal Absaroka from the Rockies. rocks in the Williston basin are the Tyler Formation estuarine, bar, and marine sands and shales (Ziebarth, 1964; Grenda, Younger Sedimentary Deposits 1978). Dense, microcrystalline carbonates and fine-grained (Terti31)'-Quaternary) red and brown clastics of the Amsden Fonnation suggest more restricted depositional conditions. Broom Creek rocks During the Tejas sequence (Tertiary-Quaternary), few in are more sandy and contain dense carbonates. suggesting durated stratigraphic units formed. Scattered limestone and prograding sands into a shallow marine b Thble 1. Characteristics of Dolomitization and Porosity Dpvelopment in Red River Formation* A, B, and C Zones D Zone Environmenl Sabkha SUbtidal and/or intertidal Fluid movement Evaporative pumping Seepage reflux ion Water Concentrated seawater with reduced ~alinity Mixed hypersaline and/or fresh water Dolomitization Subtidal. "at surface" Subsurface. interstitial ·Modificd from Carroll (I(P9). Lee C. Gerhard et al 999 simple depressed saucer with two positive structures. the tion apparently 10 the southwest (Fig. l6A). This early con Cedar Creek and Nessan anticlines. This was obviously an nection to the Cordilleran geosyncline was broken during the oversimplified view based on limited data. The diagrammatic Devonian by uplift. Uplift tilted the Williston basin north representation of current data and theory (Fig. 2) is also ward connecting it with the Elk Point basin sea (Fig. 16B). probably oversimplified. Before tracing the tectonic history Mississippian transgression coupled with subsidence of of the basin by studying the two major anticlines, a brief the Transcontinental arch system changed the seaway con survey of present structural elements and the depositional nection to the Cordilleran again. but due west through the framework is necessary. Central Montana trough (Fig. l6C). This connection per Phanerozoic sedimentation transgressed from the west sisted during the Absaroka sequence, but with greatly re across a weathered crystalline terrain, mostly of Churchill duced circulation. Clastics spread into the basin from the province rocks, but also across the Churchill-Superior boun south (Tyler), southeast. and northeast. Sioux arch sediments dary. Salt dissolution in the Prairie Fonnation in the north are hypothesized from the southeast. whereas drainage from central part of North Dakota appears to coincide closely with the Canadian shelf has been demonstrated from the northeast the approximate location of this boundary. This may suggest (Fig. 16D). later movement along the juncture. No basin was present in the early part of the Paleozoic; only an indentation was Cedar Creek and Nesson Anticlines present in the north part of the western cratonic shelf, al though Precambrian blocks were protruding from the shelf Two major 'structures in the Williston basin, the Cedar floor (Carlson. 1960). Basin depression originated in the Creek and Nesson anticlines, are oil productive and can be Ordovician (pre-TIppecanoe), with the main seaway connec mapped from surface outcrops (although the Nesson is nTH]!. ""m1 Ill(; _~c",>~~~~ I , """ I ~--~=-~_~<_ I' ",-milt} I ou x- zj 250(75) I S.lI ell \RI..-S ~~-~t=~;':4:- -~4=--~ -;;. 00 ...'I ...... I\SIPI'IAN \IISSIO' ( ""HI\ \1 \IlIS0\ ~~~ 2000(600\ : --'i~ - --=;,,~1 _~~2-~~~~ '~±'~ ~--. rOIJ(.n>()I.~ ~;-~~-~~ -:~~-~~ I§g'c' .,;SZ:¥"j$ Ou ~~~~~ fl·\",-",r' 0,' ~~ 1101351 --I ou THRn: FORKS --~-:~~J~~~~~,l- 24ll(75) 1l1RfHlE \R :-:L ---'---T' I JEFFERSON lH PHl.(11Il "0 _~i---"_-- -c=:iI.----n 460 (t ~O) SOIRI"I{I\F~ ()~'~~C :c::::::::r_~r _~\"f----. C.57!t04£~J, r-'1.\'ITOII \ "" 350(11151 0'1 r~~~-----_JI nEVO"lIAN "\I'" __ C~'A:;_''':'; __ ,""',,, HI\. 1'01'\1 "0 ~-c.- -' """", J FIG. 9-Stratigrapbic section of Kaskaskia rocks. Modified from Bluemle e'al (1980). 1000 Williston Basin, North Dakota largely obscured by glacial cover). Because of the large pre-Pennsylvanian, post-Mississippian Big Snowy interval. amount of subsurface data available on these structures, their A mid-Permian event changed the stress regime. The former structural development can be documented (Figs. 17,18). normal fault changes direction of motion, up on the west, Nessan anticline history was initiated in the Precambrian. rather than down on the west. Lower Deadwood sediments were deposited around, but not Laramide-related strain is evident during the Cretaceous, over, the crystalline core of the present anticline. Upper with a reversal of movement along the Nesson fault in the Deadwood sediments are present where they onlap the top of pre-Late Cretaceous. Since that time there is little evidence of the structure. Abrupt changes in thickness across the struc major fault movement, although minor seismic activity con ture indicate fault movement on the west flank of the Nessan. tinues along the Nesson trend. Cretaceous rocks are folded Renewed activity along the fault also affected Winnipeg across the structure and may also be faulted. deposition. Erosion between Deadwood and Winnipeg rocks A comparison of structure in the basin, contoured on the formed the Sauk-TIppecanoe disconformity. Thinning of the top of the Silurian Interlake Formation (Fig. 18) and on the post-Winnipeg·pre-Devonian section is due to renewed uplift Cretaceous Mowry Formation (Fig. 19) shows asymmetry without faulting. and steep dip on the west flank of the Nesson anticline as well Evidence of Ancestral Rocky Mountain orogenic move as indications of the other major structures in the basin. ment in the Williston basin may be reflected by a second Comparison with a map of structural elements (Fig. 2) shows period of vertical fault movement which occurred in the that the Little Knife, Billings, and Antelope anticlines, and ,~ , , ,- 'M' ... - ,- ~\------SASKATCHEWAN MANITOBA I I \ o .t "'------2000 .MILES CITY '''00 NORTH DAKOTA ~ ..._ / / ----- ., l I M~~~ __ ------JI ( I I / J .PIEl't!tf: / t __ _', ! :_----",<1' ,/./ :'---=c ~"'_"M / " "" . J ~'CA..' (- CONTOUfl INT[flYAl tOO FEET "I ,, 0- - ...... ""J WYOMING , SOUTH DAKOTA , , , T ,- - ."'.. 'M' '00 FIG. to-Isopach map of Kaskaskia sequence in WUliston basin, Modified in pari from Craig (1972) and Baars (1972), Lee C. Gerhard et al 1001 the Bismarck·Williston trend can be seen in Silurian better Red Wing Creek Structure than in Cretaceous rocks. There afe also suggestions of nonheast-trending anticlinal structures. One of the most controversial and interesting structures in The asymmetry and steep dip on the west flank of the the Wilhston basin is the Red Wing Creek SlrUClure, which Nesson probably reflect Laramide fault movement on that produces oil from a greatly ex.aggerated thickness of Missis structure. Northwest-trending structures in Cretaceous rocks sippian rocks. At the time of its discovery in 1972, this underscore the importance ofthis relatively unexplored struc structure was a seismic anomaly that fit no pattern for tural trend. Williston basin structures. Exhibits presented to the North The Cedar Creek anticline in eastern Montana has a some Dakota Industrial Commission during the spacing hearing for what similar history (Fig. 20; J H. Clement, 1975·80, per· the Red Wing Creek field interpreted this structure as an sonal commun.). No data are available to establish a pre astroblcme. Succeeding publkations by Brennen et al (975) Winnipeg or pre-Red River history. However, two periods of and Parson et al (1975) presented additional data supponing early fault movement on the west-bounding fault zone oc this hypothesis. curred: (1) pre-Middle Devonian and (2) Late Devonian It appears that sedimentation across the structure followed pre-Mississippian. Faulting then reversed direction during normal patterns for the \\'illiston basin through Triassic Late Mississippian (Chester) through Triassic time. At this (Spearfish) time. In the Jurassic, a major structural disruption point, a minor subsidiary fault in the Gas City area developed of a very small area occurred (Fig. 2J), which has been locally (J. H. Clement, personal commun.). No major fault interpreted by previously cited writers as a meteorite impact. displacement has been documented affecting Jurassic, Cre This event was apparently pre-Piper Formation. since red taceous, and Tertiary strata (J. H. Clement, personal sandstones anti siltstones fill a ring depression on the commun.). Spearfish and below the Piper, although in samples it is West East KIBBEY FORMATION + + + + + + .. ~ + + + + ~+ + + + + + + + + + + + + + + + + ...... +++ ++~++ ... + .. + ... ++++++++++++++++ + + + + + + + + -~ + + + + + + ~ ~ ;: ...... + + ..- T + +I:'t' ~ + + -+ -+ T + + ...... _ ... + .. + + .. + + 'V J:::a + + + -'-R'" + + + + + + + + + -'- ..... ~ :::~ ~ ~ T.~~Y~~ ~ _-~ : : : :: .... ::: + r?f!-... 1f'J.. ... ::::::::::::: :: + + + + + ~ -~ + + + + + + + + + + + + + -'- + .. + + .. -'- + -'- .. ~ ~- ~ j • + •. + .. , -l + + j • + .. , .. , .. -'- -'- , + ~ 0- + + ...... + + ~" ~ .. " + - + + + + + + + + ... ++...... ~+.jo++.jo+"++"++",,,",,,-'-"'.jo+""'''''''''+''''''''''''+'''++''''+.-+''''''''''''++'' .. ,. I~ ++ TERVA + ... +++ ... ++ ... -l+++i++"'+ : + ... '-I ... :<" r +: .. + + .. ! ..... + RATCLIFFE IN L + + + + +...... - M\O LE suB- NT VAL ... " -\NTE RVAL' + + + + + + ... --- -- ...... + + + ... + ... ~ o 0;;;:' . HHHH.H" .... H.H A. :-.;;: ~ H ..H"""'''·· ::3 o ,~ ~ _~ FROBISHER-ALIDA INTERVAL .. ·······1 C ~,,~~ III ...... ~ ... ++++_.. + .....+...... 4.0 TILSTON INTERVAL - ~ ~.i~ ~.r,,~ 60 £.AU \Nl£.~\JJl,l: 111N , ~-'" c:)r_~' O-~· ,¥J.-cS' - 5i. .~OE"ON\~N FIG. It-Generalized cross section of Mississippian rocks in Williston basin showing relationship of facies and stratigraphic nomen dature, Modir..d from Carlson and Anderson (1%6), 1002 Williston Basin, North Dakota difficult to distinguish true "crater fill" from Spearfish For We hypothesize that both the Fromberg and the mation clastics. The discovery well (True Oil 22-27 Bur Colorado-Wyoming shear zones were formed by left-lateral lington Northern) cut a very thick pay section in disturbed shearing in the edge of the pre- Phanerozoic continental plate. Mississippian rocks. Much of the picture of the Red Wing This shearing displaced the present northern and southern Creek structure is apparently based on seismic infonnation as Rocky Mountain blocks, catching the present central Rocky well as interpretation of complex well logs and samples. Mountain block (with the Black Hills and Big Horn uplifts Renewed movement on bounding faults is seen as high in this therein) as a slice between the shears, resulting in left-lateral section as the Dakota sandstone. drag. The central part of the structure is an elevated block, Initial shearing resulted in the formation of numerous surrounded by a ring depression. The geometry of the struc basement-rooted faults within the central Rockies, Black tuce is clearly cryptovolcanic and it is difficult to argue Hills, and Williston basin. Since that time, it is questionable against a hypothesis of meteorite impact origin for this com if any significant motion has occurred along the two major plex structure. Bridges (1978) suggested a section of several shear zones. However, evers orogenic episode with major faults which change orientation through time (concentricline) influence on the North American plate would apply stress to as an alternate hypothesis. Others have suggested that this the system and many of the associated faults show some structure could also result from deep-seated igneous activity Laramide displacement. We theorize that the shear system (diatreme). Detailed analysis of samples may detennine the validity of the meteorite impact hypothesis. Newporte Structure A EPISOOE II :POROSITY DEVELDPMENT; , ' In north-central North Dakota, the Shell 27X-9 Larson 1 ! , ' discovered oil in Deadwood Sandstone (Fig. 22; Clement and , ' Mayhew, 1979). Continued development of this field demon , ,I ~\\. \. : I LOFERITE POROSITY--;" ~ I , strated the complexities of the Williston basin as well as one J of the rare oil wells producing from Precambrian crystalline rocks (Shell 14-34 Mott). Interpretative cross sections (Fig. EPtSOOE m 23) suggest that Deadwood Sandstone was deposited be tween Precambrian hills in part, and that pre· Winnipeg SABKHA ENVIRDNMENT : (post-Sauk. pre-TIppecanoe interval) erosion and faulting , created a small basin of detritus from Deadwood and Pre : p.\.GAE cambrian rocks. Winnipeg sedimentation covered the struc : ~~ f..\JAPof?/)-' '<"~ ture, but was in part cut by at least one growth fault. "",e, , 0 <" An alternate hypothesis, presented by Donofrio (1981), &... "I:::' <$j"v" suggests that the Newporte structure is possibly a meteorite <:5 «-'0 ",> ,I/o impact feature. ," 8 .../"", c,'" o;/F', '9'y~,,0 '" ""'-v~ Y e,~ ~ ~~o ~ ~. qO q"'~ ~ 't::9 ; ORIGIN OF WILLISTON BASIN ;.;....q , "'..... q'" Since Middle Ordovician time, the Williston basin has subsided approximately 16,000 ft (4,875 m) without under SHALLDW MARINE going severe orogenic deformation or severe peripheral tec tonic distortion. Recent mapping of heat gradients in North Dakota (Harris et a!, 1981) suggests no abnormally high heat flow that would indicate any "mantle plume" or "hot spot" beneath the basin to account for its subsidence. Several EPISODE Ill: papers have advanced wrench-fault systems to account for the generation of known structural elements in Montana and North Dakota, but none have championed a specific origin VADOSE PlSOLlTE (Caliche) for the Williston basin. DOLOMITIZATION The change in structural grain between the central and I ANHYDRITE ...J northern Rockies takes place at the approximate location of the Fromberg fault zone at the north end of the Big Hom FIG. 12-A. Generalized sections of map showing porosity uplift. This fault zone, of unknown age, trends parallel with development in Frobisher-Alida zone, Glenburn field, North the Colorado-Wyoming shear zone. Casual observation Dakota. Episode II illustrates porosity development by fresh water weathering and desiccation. Episode III indicates rela demonstrates a northeastward linearity of the Fromberg zone tive position of several strandlines and depositional or with portions of the Yellowstone River course, the north end diagenetic lithologies. Episode IV demonstrates formation of of the Cedar Creek anticline, the Watford deep of the porosity through generation of vadose pisolite or caliche. B. Williston basin, and a saddle in the Nesson anticline (Fig. Loferite shrinkage or desiccation voids overlain by subaerial 24). To the southwest, west of the Beartooth uplift, the same laminated crust, in turn overlain by pisolitic lolerites. Thxota 1 linearity defines the Snake River plain. Weber at 4,600 ft (1,406 m). Scale on photo is 3 em long, (Figure B on next page). Lee C. Gerhard et al 1003 and its dragged blocks have been repeatedly "tensed," with interpretation (Fig. 25), but we do not espouse that idea. An resultant vertical motion along basement planes of structural alternate idea is one of a large-scale "puB-apart basin" simi dis<:ontinuity This does. not preclude motion along the majur lar to that proposed by Burchfiel and Stewart (966) for Death shears (e.g., Laramide displacement on the north end of the Valley, California (Fig. 25). However, the origin of the Big Horns along the Fromberg zone), but does not require it. Williston basin as a structurally and asymmetrically de If this hypothesis is correct, the following conclusions can pressed block formed at the Tippecanoe-Sauk sequence be drawn. boundary as a northeast extension of the central Rocky I. The central Rocky Mountains were a depressed block Mountain block is attractive to us. This would be a com during Ordovician-Silurian (Tippecanoe) time, as demon plimentary distortion to the eastern North American Taconic strated hy the marine connection between the Williston basin orogenesis. and the Cordilleran sea during Tippecanoe sedimentation 2. The Devonian movement of the Transcontinental arch, (Fig. 16A). The northwest extension of this depression is a which we have previously suggested is responsible fur the "graben-like" or depressed Williston basin block. The opening of the Williston basin into the Elk Point basm on the geometry of the shears and block mig hI lead to an aulacogen north (Fig. 16B). would be geometrically controlled by the B PISOLITIC LOFERITES - CRUST >VOIDS (Continued). 1004 Williston Basin, North Dakota presence of the Colorado-Wyoming shear zone. The source OIL AND GAS RESOURCES of the tectonic stress could be both eastern (Acadian) and perhaps western (Antler) deformation. Oil was discovered in the Williston basin in Montana on 3. The geometries ofcentral Rocky Mountain structures in the Cedar Creek anticline (1936), in Manitoba (1950), and in Wyoming, the Black Hills, and the Williston basin all fit a North Dakota on the Nesson anticline (1951). More recently, left-lateral strain model in both general morphology and several significant cycles ofexploration have been completed angular relations (Fig. 24). in North Dakota and another is in progress (Gerhard and 4. The Mondak Mississippian field of the Williston basin is Anderson, 1979, 1981). Annual production increased until a very large (at least 100 million bbl) oil field, producing from 1966, then declined until 1974. It is now on an uptrend which, fractured Mission Canyon Formation carbonates, without in 197,9, surpassed the previous high (Fig. 26). significant structural closure. The field and its "look alikes" Although the initial discovery was from Silurian rocks, the lie on the homoclinal east-dipping flank of the Cedar Creek early development of the Nesson anticline was primarily anticline. Although various schemes to explain this oil field from Madison reservoirs. The peak discovery period was have been advanced, such as underlying salt solution (Keams 1952-53. Development along this 75-mi (120 km) trend was and Traut, 1979), none has been satisfactory. Application of nearly complete by 1960, with producing capacity exceeding the "tensing" theory advanced here might be a more satisfac the available market. Production was limited then by prora tory explanation for the reservoir fracturing here and in other tioning until November of 1965 when natural decline of these fields. reservoirs equaled the market demand. The only significant Well-indurated Mississippian carbonates are bounded deeper zones developed along the Nesson trend during that below by Bakken shales and silts, and above by evaporite, time were the Duperow and Interlake pools in Beaver Lodge both structurally incompetent lithologies. Tensing of these and Antelope fields and the Sanish pool in Antelope. rocks would produce no apparent distortion of the incompe Widespread wildcatting around the state in 1954 had a tent beds, but the competent carbonates would develop notable lack of success except for small discoveries in Bot closely spaced jointing (fractures). This hypothesis could tineau County. The Jack of success slowed exploration until also account for fractures reported from the Little Knife 1957-58 when the Burke-Bottineau stratigraphic trap play Madison field, as well as others by analogy. met with success. The increasing production during 1958-61 As basin studies advance, new structures, evidence of (Fig. 26) largely reflects development of these pools. Produc greater amounts of fault displacement, and suggestions of tion from this area was marketed first by rail and then. in long histories of structural distortion of major structures are 1963, via the Portal Pipeline to refineries in Minnesota and being documented. All ofthe newest structural data available Wisconsin. The slight increase in wildcats in 1964 reflects the to the writers appear to complement our hypothesis. expanded market provided by the pipeline (Fig. 27). No major relationship between our model for the origin of In 1960. discovery of the Cedar Creek pool extended Red the Central Rockies, Black Hills, and Williston basin and the River production along the Cedar Creek anticline into North development of the Wyoming-Montana overthrust belt is Dakota. The Bowman County Red River play extended pro apparent. Certainly, deformation of that tectonic province duction in this area to small "highs" along the eastern flank of exerted stress on our area of interest. There is considerable the structure in (he period from 1967 to the mid-1970s. evidence of Laramide and post-Laramide defonnation in the Tyler sand reservoirs which were discovered at Rocky Williston basin. In our opinion, however, the Laramide de Ridge in 1957 and Fryburg in 1959 became important de formation created the stress that once again "tensed" the velopments in the mid-1960s in the Stark and Billings County Wyoming block and provided for the vertical uplift of many areas. Peak production in 1966 at the Medora field and in Laramide structures now present. The structural grain of 1967 at Dickinson field helped offset declines in the older these structures is still inherited from the Proterozoic left producing areas. lateral shear system we have hypothesized. The decline in production from 1966 to 1974 represents the TRIASSIC MtJOf. ~ c--=<'c: ~:;;='" SPfo\RFlSH ------750 (225) PI!'lE: SALT ISalt OELFllLD Oil ~~~:~~~~~:; \11...... fKAHTA ~~~O_ 40 (t2) PERMIAN ~~='EO""''''--~I OP[CHE ~-:;-;~~~- ~3 400 (120) BROOM CREEK Nitro- 335 (100) g FIG. 13-Stratigraphic section of Absaroka sequence rocks. Lee C. Gerhard at al 1005 Iillldo) Eucene (;A~E:LS onn : --"'" COLD.:",,, ,\J.I.E\ I . Clay ~ -,,~- -' "" ~ r ~ ~ I Sli,~~'~,'1 :~r~~} I 1 ""'n" ~ I w.... I f -~., I Pal"lICCflC tORT ,~,;::; ~,~r~==-;t~~'._~ ~ I ( '10'" w,i~ .".,,,,,, •• '""""~':'~:::=,f.-,," :._ 650 (ZOO) I ,.," .:, .~_~~ I 'J, '00" _~----"-=-~__ l- Chnker ~~ I _L SlO" I 1:.\"'0'8\1.1. 650 (2001 \~:\:;, ~-----e-~:__-=:"-~ I UlJl.O\\ ~~C':~~~;;, .... ~ =:- -::::., ~ -_- -=-~ -0-, 500 (ISO) HELL CRtT'" '.,., N-T-~~1~ v I I I "'!CUIll,H~.AIl i I r III 400 (120) HI'IIlLl.S W.IO, It\lllHt LAKE: S1 "'m'd \'\, -~- lIH.IU\ fIHUH. ~.~.,~., 2 300 (100) , (.RH.OIO ;; pF'ml'" ('KITACH}L'S ~;~ 1,\\1\10\ ~-:t-~-:; ~tRRlbl\()\" -f ~~~~~:1i-~~ '\IOtlK\R\ 250 (75) ----.:------= ~.=.- =,==<~ L\MUU: 400 (IW) l.OUIH\UO '<=---00. GREE~HOR' l I 1~0~~~_-1f!~-V ISO ('5) I I ""::.::'"' I ~~~~~[~1M (55) ~F.WC"'STU: llI.le. 150 (45) DAKOTA ! SKULL CREEK ~,~~~~~ 140 (40) =--:-;-;; Wau, INYA~ K,4,R.\ 4,>1)(135) I !'llORRISO\ I ~.~~""",, 260 (80) ",,"Ui 500 (ISO) , ~!ii;'~~~if71 I JURASSIC 100 "OJ =' ;"0 FIRE'olOOS"""" TA'olPII'(l PlnR KU~. ~~ 625 (190) PI{:ARO ~~~~:tl~~~{ IJl ~llA'I1 sur FIG.l4-Stratigraphic section of Zuni sequence rocks. 1006 Williston Basin, North Dakota failure of new discoveries to replace the natural decline of the actual wildcat drilling. The price increases created risk capi· major producing areas. The normal pattern is discovery, tal, and thus exploratory drilling was enhanced. followed by development leading to peak production (l to 3 It is interesting to note that exploration and production years) and then gradual decline. Secondary recovery have followed technology. Initial production was from Nes methods usually alter this pattern. Water injection for pres son anticline seismic prospects. Amerada Petroleum Corp. sure maintenance was installed in many of the Madison drilled a string of successes 75 mi (120 km) long without a dry reservoirs along the Nessan trend, but was relatively unsuc hole. As interpretation of basin geometry progressed, cessful. Similar programs in the Newburg-Spearfish, Madi !>tratigraphic/structural traps were defined along the northeast son reservoir in 1967 and in the Tyler sandstone reservoirs of basin flank. Later, in Bowman County, North Dakota, seis Dickinson field in 1973 and Medora field in 1970 increased mic surveys successfully defined small Red River structural production levels above the initial development peaks in "highs." Stratigraphic plays and long-shot deeper drilling those fields. However, these successful programs could not sporadically generated interest until the well-known unusual offset the natural decline of the major producing areas. seismic configuration at Red Wing Creek became productive. The trend of lower exploratory acti vity of the 1960s gener Assessment of future production involves an evaluation of ally followed the national trend. The upsurge of wildcatting source rocks as well as reservoir capi1bilities. Geochemical in 1968 has been referred to as the "Muddy sand" play. It studies have classified Williston basin oils into three types. followed development of the Bell Creek field in Montana, but Based on carbonate isotope studies it hi1s been postulated that no similar occurrences were found in North Dakota and the source rocks for most of the oil are the Winnipeg shale for exploration activity again decreased. type I, the Bakken Formation for type II, and the Tyler shale However, two events, occurring close together, signifi for type III (Williams, 1974). Dow (1974, Fig. 2, p. 1258) cantly changed Williston basin production history. The Red further estimated reserve volumes as: type I, 600 million bbl: Wing Creek field was discovered in McKenzie County, North type II, 10 billion bbl; and type III, 300 million bbl. He Dakota, and OPEC placed production controls (embargoes) estimated that 50% of type I, 30% of type II, and lesser and price increases on production by member nations. quantities of type III oil had been discovered at that time. The Red Wing Creek discovery excited basin oil operators The writers, and others who have studied the rock sections because of the relatively high productivity of the wells and in the basin, would agree that the Winnipeg, Bakken, and because of the anomalously thick pay section. Because no Tyler represent the most concentrated source of organic mate one really understood the nature of the Red Wing Creek rials; however, we believe that many producing zones con structure at the time, industry's only possible response was to tain sufficient organic material to have been the source them gain leaseholds in the area. The leasing activity set off by the selves. Specifically, the Red River, Birdbear, Duperow, Win Red Wing Creek discovery set the stage for further develop nipegosis, and Madison have sufficient indigenous organic ment. The now common 5-year-term leases of western North material to provide large quantities of liquid hydrocarbons. If Dakota tended to increase exploratory activity as compared so, there is much more oil to be found in the Williston basin. to IO-year leases. The lease play, coupled with the sudden Ifnew pool discoveries are compared to preceding curves, availability of venture capital, caused exploratory drilling to the significance of the present development boom becomes begin to increase in 1975 and 1976, partly in response to the obvious (Fig. 28). High levels of wildcat activity have had a lease expiration dates. corresponding peak of new pool discoveries. except during OPEC made the first substantial increase in oil prices, so the 1954 east side and 1968 "Muddy" Sandstone wildcat exploration could be a profitable venture. Prior to the in programs. The number of new pool discoveries per wildcat crease, many companies found that exploration risk money drilled has risen dramatically in the last 4 years. This increase had a better return in a regular bank savings account than in in success is attributed to (1) the use ofCDP seismic methods, H I I, ,'" .. -'-:-., I oocene nAHt: w.....·- . G••v•.~~.: ';" •. ' 0:' \ SO(IS) ;; I /.~.~.-, ~ I ~"MEu r ~ I ~~ir:i~IVER (;.ovoJ .':." ~ _.~ ::).:;>..~ ~ I PleIstocene COI.EHARBOR FALCONER ~~,~r;1'I" 'II."', of ,~•• ;.'~ .". o WYL]}' St<:>n•.. '.. ' 1000(300) I ~'6~~ESSCHHOOEOL DAHLEN RfD L"KE I'''LLS ~~~:: ~-_ 4. • _ _;;. I ~ M~~,~~~i GARD"R 5T H1L"IRf: ., .~ '0....,; to ~ ~ HILL V"N{, M"IICOl'X ll'lwn..ou. ",.m.d ...d u",nam.d unol., / I Guv.1 Plio",... , ...... I (I,nnam..d I ",II c" , 300(90) ~ ~ '1-----1 ~~.~ '~"?' -... I ...locrne (llnnamed Iln,l) ~~_7:::-''''''' . ....c -' Ill: I "':-"_.- -~ 400(120) ~ . RRI'U: - ~ -::- --- lS FIG. IS-Stratigraphic section of Tejas sequence rocks and sediments. Lee C. Gerhard et al 1007 (2) better reservoir geology, and (3) completely revised test province. During L970 there was an average of 20 active ing and completion techniques. drilling locations in the entire United States portion, whereas Dramatic expansion of producing areas has occurred dur during 1980 there was an average of ]50 active drilling ing the present cycle, including new producing counties, new locations. pay zones, and new producing depths. The maps of North Current activity is centered in we~tem North Dakota and Dakota producing fields in 1970 (Fig. 29) and 1980 (Fig. 30) the bordering Montana counties. Significant new discoveries illustrate the resurgence of the Williston basin as a major oil have been the Little Knife Madison in 1977 (109 wells, 125 A B ! ,/ \, \ \ \, '"( ~ --~-- J -~, \ ~ \ ~ j ;; , 1 ~----, N N .",. '1 j ~, r-~.I'- I '-----1 l'" I lQlIII,l[$ , - '00, 0 '00 100 9 ?l ~oo Mil ES ~o'" \ , , , ,, i , , i '" _ _. 500 ""LOIIIE HilS 00 ° '00 200 3OQKILOMEnFlS 'v -'\ "" 0 '00 '00 LOWER KASKASt ROCK TYPES ~ Evaporit•• ~ Dolomite ~ limUfon. f=;,:..:-.:::,:,] 50ndy Siltstone t-=-_-=-=~ Shale t:.;:~:i;~l Sandstone c o \, ! (l \ \ \ \ \, \ ~ \ \ \. -, - ~J\ \ I --~ • SHELF N ------, i, I 100 0 00 lOO III,LES I '00 0 '00 200 M'LES " Ii!; , I ~---~ ...... -. , ! i " OJ 0 100 zoo '00 IlllOM[URS .' '00 0 tOo 2Cll ~oo KILOMETEl'IS \ UPPER KASKASKIA FIG. 16-SequentiaJ maps showing marine communication directions during times indicated for Williston basin. A. Tippecanoe sequence, showing connection with Cordilleran miogeosyncline on southwest and eastern interior on southeast across Transcontinen ta. arch. Modified from Foster O(72). B. Lower Kaskaskia sequence communication to Elk Point basin in Canada. Modified from Clark and Stern (968). C. Upper Kaskaskia. showing communication of Cordilleran miogeosyncline through Montana trough. Dark spots at entrance and along edges of Montana trough represent bank development. Some bank development is also h)'pothesized within basin. Modified from Bjorlie and Anderson (1978). D. Absaroka sequence, showing flood ofclastics from southwesl as well as from drainages to 11Ortheas1 and east. Sediment flow probably occurred from farther southeast also. Modified from Mallory (1972a, b) and Rascoe and Baars (1972), 1008 Williston Basin, North Dakota million bbl reserve), the Mondak Madison in 1977 (112 wells, was $294,000. In 1978, the annual total was near > 100 million bbl reserve), and the Billings Nose area where $20,000,000. In 1980, for the last quarter sale only, over there are Madison reservoirs and Duperow wells that have $30,000,000 was paid. recorded initial potentials over 2,000 bbl/day and a few with The future for oil and gas production in the Williston basin potentials over 3,000 bbl/day (158 wells, 100 million bbl looks bright for the next few years. New rigs moving in, reserve). major exploratory programs under way, and high lease prices Another significant recent development is exploration of all support a continuation of the present exploratory boom, deeper zones along the Nessan trend. with several years of developmental drilling needed after Shallow gas plays are in their infancy in the basin. but are exploratory drilling decreases. in process. Air drilling is necessary for adequate testing of Financial impacts on the state of North Dakota from the oil Pierre (Judith River and Eagle sands), "Muddy," Inyan business are very significant. For the 1980s, oil~ and gas Kara, and Niobrara rocks, but these rigs are uncommon in the generated revenues will be the most significant single source basin, and surface holes can be a problem with air drilling. of income lO the state government. Little testing has been done on the southeast extension of the Antelope anticline, an area that industry has only recently OTHER MINERAL AND ENERGY RESOURCES begun to delineate as a major potential hydrocarbon area. Stratigraphic traps around the Cedar Creek, Nesson, and The Williston basin contains two major resources besides Poplar anticlines are mostly untested, as is much of the hydrocarbons, although present production ofeither does not eastern and western basin flanks. begin to compare with the value ofthe hydrocarbon resource. The northwest shelf, west of the Nessan anticline, holds Lignite is actively mined and is a significant energy and promise and has been tested mostly on the Montana side of revenue producer in North Dakota. Potash resources are not the basin. Many prospects remain to be drilled. yet being mined, but serve as a damper on potash prices in the In 1970, the total bonuses paid for the year for state leases world market. especially on Canadian resources. NESSON ANTICUNE PRE - MIOOLE MISSISSIPPIAN PRE - PENNSYLVANIAN w BASE BAKKEN w 8ASE TYLER E )'~)~~)~~j)~~~~j,~~jj~~Ij-IOjIII~)'~~~j~~~jIr~'jljl~~~lj~~lll~~-i-~ttI]~~U >OOd PRE -UPPER CRETACEOUS W TOP MOWlrY E "::::::_:_::_=:::::=:::::_:::::.::_::_ ~; .::{_::::::::::::::::::?=:=:=;=::_:::-:_::=:::-::-=~:~:-:K:~! ::::_:_:::::::::::1 0 MID·P(RMIAN W MINNEKAliTA. BASE SPEARFISH E i:;:::::~::::~:~:~~~~~~~I~~n~~~~~~~~~JI~~~~~~~~i~ii;~?~[~I~~~~~~~~ ItI 'I:I~"'~ !!.-~--~~ii~----:~;!:-:~-~:--~::~:~-::~!~:_~:_·~~i;~: I5-1-1;_-~-;--~jl~li--III;__!_1:_!--1i;}j-li;:;;~l;a,ii~j~j~~ 1000 - 200'" ,m I FIG. 17-Diagrammatic cross sections of Nesson anticline showing structural development. Note apparent reversal of fault move ment during mid-Permian. Some of pre-Upper Cretaceous movement may be related to salt solution. Lee C. Gerhard et al 1009 Deposition of Prairie Fonnation evaporites, after restric of the basin (Fig. 33). Lignite occurs as part of the Cenozoic tion of circulation in the Elk Point basin of Devonian time, rock suite derived from erosion of the Laramide Rocky created a very large resource of salt and potash in the Mountains. These rocks, generally called the Fort Union Williston basin (Figs. 9, 16, 31, 32). Within the Prairie salt Group, are mostly of terrestrial origin, although the Cannon section of North Dakota and Montana. three potash units ball Formation, in the lower part of the Fort Union, is the occur: the Esterhazy, Belle Plaine, and Mountrail Members youngest marine stratigraphic unit in this area (Fig. 34). (Anderson and Swinehart, 1979). At the present time, potash Mining is now exclusively by surface techniques, but earlier is being mined by both conventional underground and solu in the history of North Dakota underground workings were tion methods in southern Canada. Approximately 50 billion common (now a source of major environmental concern as tons (45 billion Mg) of potash lie south of the international they collapse). border in North Dakota, with additional resources in Because this lignite has low-sulfur but high-water content. Montana. most of it is utilized close to the mining site for electrical During the mid-1970s increasing world market prices generation (Fig. 35). Despite the national need for additional coupled with both export taxes on Canadian potash and energy resources, severe restriction on leasing of reserved action by Canadian government to take control of the Cana· federal coal and stiff reclamation policies have held down dian potash mines created a flurry of leasing and pre-mining production increases. StiH, production in North Dakota has activity in North Dakota and Montana. Since the depth to doubled in the last 5 years as new electrical generation plants minable potash in the United States portion of the basin have gone on stream (Fig. 36). The 20 billion ton (i8 billion precludes conventional mining techniques, solution mining Mg) reserves and 350 billion ton (318 billion Mg) resources was planned for North Dakota. A price stabilization occurred specify that the lignites will be major energy sources for with renewed exploration and plans for development in 1976. decades. As production from the New Mexico deposits wanes, the Williston basin deposits will serve to prevent any world SUMMARY potash cartel from major price increases. Our 50 billion tons (45 billion Mg) of resources insure the domestic supply of Geological analysis of the Williston basin has benefited this critical mineral. from expansion of the subsurface data base by renewed oil Lignite is a major energy resource in the North Dakota part exploration, application of computer techniques to dat~ han SILURIAN STRUCTURE MAP o to 20 30 40 50 MILES I I" I "I' , o C203040~ KILOMETERS FIG. 18-Structure map of top of Silurian Interlake Formation showing geometry of Williston basin in North Dakota. 1. Billings anticline; 2, Little Knife IDticline; 3, Bismarck-Williston trendj 4, Nesson anticline; 5, Antelope anticline. 1010 Williston Basin, North Dakota STRUCTURE MAP ~ 00 '" Contour Int.rva I 200 f.et oI 10 ' 20 , 10 , 40 , 50 , MILES , ii' i o () 20 ~<4050 KILOMETERS FIG. 19-5tructure map of top of Mowry Formation (Cretaceous). Compare Figure 18. Closely spaced contours on west side of Nes son anticline suggest post-Mowry faulting on that structure. Bismarck-Williston trend also appears to be well developed as is Billings anticline. I.ittJe Knife anticline does not appear to be so well defined at this horizon. CEDAR CREEK ANTICLINE POST-SILURIAN PRE-MIDDLE DEVONIAN LATE MISSISSIPPIAN EARLY PENNSYLVANiAN w LATE DEVONIAN PRE-MISSISSIPPIAN NNS,(~"A"'Ill,N TOP AMSD!:N _8~(, • E SNOwY _ a eAsE MISS:SS,PPIAN ~ MADISON 1000' m~1:fffi!fe;g;sm~~'~~i#if~QOO t DEY NIAN ~ " '- J ~ cS ~~U~'¢N:-' '. 2000 I' INNI EG-":. _ _ _ 3000' MID-PERMIAN PRE - MIDDlE JURASSIC • w TOP MINNEO o I MILE FIG. 20-Diagrammatic cross SC(:tions across Cedar Cref:k anticline at Gas City field. Modified from Clement (1976). Minor second fault generated locally in Gas City area during Late Mississippian-Early Pennsylvanian episode was concurrent with minor reversal of movement on principal west fauU zone. Lee C. Gerhard et al 1011 dling, and detailed environmental and diagenetic analysis of accompanying uplift of the Laramide Rockies provided cores and cuttings. The study of these new data indicates a paludal and fluvial environments that trapped much sediment much more structurally complex basin than heretofore was moving eastward from the Rockies in Paleocene time and realized. assisted in the formation uf t:x.tensive lignite deposits. Basin evolution in Phanerozoic time begins with Sauk The basin appears to be the result of drag along two (Late Cambrian) transgression across a rough Precambrian left-lateral shear system.s. These shear systems formed a topographic surface. but without definition of the basin. depressed block which now encompasses the central Rocky Tippecanoe sequence rocks show the initial depression of the Mountains and southern Williston basin. Tensing of this Williston basin with seaway connections west and southwest block during plate-wide orogenic stress created the vertical to the Cordjlleran rniogeosync1ine and a probable connection structure seen today. to the Mid-Continem as well. Substantial quantities of lignite, potash, and petroleum are During the Kaskaskia sequence, movement along the present in the Williston basin. Lignite mining for electrical Transcontinental arch tfend tilted the Williston basin north generation is a major industry, but potash resources are not ward, creating a marine connection on the north into the Elk yet being mined. Point basin dur1ng the Devonian, while shutting off the Oil and gas produdioll is rapidly expanding in the basin, as earlier Cordilleran and Mid-Continent marine connection of several new structural trends have been mapped in recent the TIppecanoe sequence. During the later part of the Kas years. A very high success rate in exploration drilling has kaskia sequence (Mississippian), the nOithem connection doubled oil production in the last 4 years. Continued in was cut off and the Williston basin reconnected to the Cordi creases in oil production are forecast for the next few years. lleran sea through the Central Montana trough. Several of the structural trends now heing mapped have not Pennsylvanian structural disturbance in the southern Rock been substantially explored, and shallow gas potentials have ies (Ancestral Rocky Mountains) disrupted sedimentation been largely ignored. patterns of primarily carbonate-dominant lithologies in the basin. Beginning with the Absaroka sequence, clastic REFERENCES CITED sedimentary facies predominate in the Williston basin with interspersed evaporites and a few carbonates. Anderson, S. B., 1974. Pre-Mesozoic paleogeographic map of Nonh A full marine setting was established during the Creta Dakota: North Dakota Geol. Survey Mise. Map 17. ceous as part of the Western Interior seaway. Regression --- and R. P. Swinehart, 1979, Potash salts in the Williston basin. TRUE OIL M,. 2 2 • 27 8yrtill9loll ftarttlen. (SE NW SIIetlOll 271 TO 13,710 Rllld Riy,~ A <> • ••• -Q .' ~RIM--+--RIN6 DEPR£SSION II CENTRAL UPLIFT I RINt; OEPR£SSION-,+RIM_ -~ooo ~ ~,~ rop or DAMor .. _~D'kOT. '~ --- t III SWIFT ·4000 1~-0JI I: 1\1 I _~~~~~~:=~-_~~-~:::::ON ••. • . . ::==SPEARF'ISH -!>ooo ~Eb > :.::;:.... ,":::'>:.':-:: :":":.'. ".: .". ". '. 1 PERMIAN 'ulld.tt.r...liat.... ) r :;,;.;;.,,:'; ~ ....• ····Cr.t'r Fill :.:;:... I =IlIIMNEKAHTA ~ .~: ! ---J :.>..: ' .• ". / l~>1IL//1 ~ ",' ..•• ". ". : ',: ". -::. OPEC HE :. , .. :-.::.:: .. : --7 1""':-1 ~~ ~ .•.. :', .. ' :.;.... J - --YINNELUSA-...MSDEH "" " _'L.ASlCA IENCH ,~,~ _'.,, __ ~ I __ TYLER-HEATH '6000 j:l ;:?0'i "" OTTER i III\~ - ~/:;;:4,,~ ~ -~ I!' = "'BEY --.di U / ~"!fl ,'" -moo I CHARLES 'j ""..... -7/ //.1' c;J::.~ ~ ~ ~~~.:~'i\ ~ I ,',.. ' . =MIDALE "pc. ".• ;;/_ ~:i:iiL 1/WI I MISSION CANYON -'-, "',-' -.-,~ I ,~.~,~.~. . ~"" ",co. ' .. ",' /"/~~~ 7~ x\ , . \ ; LODGEPOLE . - , \ '", _ RED WING CREEK , , .,, INDEX \lAP FIG. 21-Cross section through Red Wing Creek struclure. McKenzie County, North Dakota, demonstrating meteorite-impad hypothesis for origin of this structure. True Oil 22-27 Burlington Northern discovery well was drilled on top of central uplift. Modi fied from Exhibit 6, case 1152, North Dakota Industrial Commission, submitted by Union Oil Co. of California. 1012 Williston Basin, North Dakota A SHELL LARSON 2~X-9 SEC 9 T11l'N RaN lPf ]1 BOPO 10... .." GAR'1~ ••0 RIVER WINNIPEG -< i FlWD (80"11, ~2) DEADWOOD REC 5 8GCO a ., TD '736 B c STRUCTURE SHELL TOP WINNIPEG MOTT 14-34 SEC ]4 TlIIN A1I7. R 81 W GAM"A .AY SONIC ~~ ,.4T \ N ~-"oo .,0° j)r ( - " ~.... \ \ I ..0 RIVER T 163 WINNIP£G N _?_?_--=--~z PRECAMBRIAN 'os 00 \> C I 100FT "-- "" j KllOM£TER TO 9490 FIG. 22-Newporte field structure map and lithologic sections. A. Shell Lanon 23 X~9. sbowing producing interval in Deadwood Formation. B. Structure of top of Winnipeg Formation in Newporte field. C. Shell Mott 14..34, showing produdng toten-als in Pre cambrian Bnd at Winnipeg Precambrian cootset. Modified from Clement and Mayhew (1979). Lee C. Gerhard el al 1013 CONCE PTUA L CROSS SECTIONS NEWPORTE FIE LO • A A' SHELL $I'I[LL SHELL.' SHELL SHELL MaTT 14·30( MOTT 32X-3 W'SOAHl. 23-10 LA.flSON 2SX-9 MOTT 14·S. "UNTOIt T;~':~~.. ,,'j~'.' ~_'2--"" -7000 O_TUII ~~'i;;.j-~:~~ -/~~1'~':0~~:-:~_~~,;~:Tti~~ -7000 '.l,,''t,-''L,'t''''r T.L~,·,:Jrr:-__·~j R£D:-t-," '~I· . ..',;;.', ~~j:;-:~(-; :,r. >I ,'/ T'''l' ,r~ -~: ,~.;'VER,~ .\l ~-, _... r~~: ~:~" , l.' J I. ,t ': r', 'r, 1" f1).1.u(l~:;:::r BOO W'N"-'PEG .:~'. -~O£AO;~~~~~"..-e-.-,-~ '.;-.' ,. ·1000 ,~~:",s.~$~ .. -sooe> LJ ~~~;;t, v, , MILE ,-_-;::======:::;-_~IM'L[ 1.,LOllEn" , "'LOlllET£~ FIG. 23--Cross seetions across Newporte field. See Figure 22 for lines of section. Modified from Clement and Mayhew (1979). J_m-r;;(.',~:;'1, __ J\ \-...... ,...--.. / I ~ ''?", ,"";? tl"" '-'·11"" .. / / /'1, \ /, 1,'1."~·' //"; \ TY I ) /': \ ~", ~ ~ /'~.y ... -- .,....------.:!.-----....r- _ \., , ~ ~\ ?' I ~,~ l > , lo'::: / o#ft ' :I:~o/ ~---Y/~r) I / -I~.,.% L_ "- !i/~,. , ---'-" . __ , - \- -1 u 100 200 300 K,\O ....lt'. ~ ~1OO.1I."".'" , , / __ FIG. 24-Diagram showing relationship of Fromberg-Colorado-Wyoming shear zones to structural features of Rocky Mountains and Williston basin. 1014 Williston Basin, North Dakota U.S.A.: Nonh Dakota Geo!. Survey Rept. lnv. 68, \9 p. stratigraphic column: North Dakota Oeol. Survey. Baars. D. L., 1972, Devonian System, III Geologic alias of the Rocky Brennan. R. L.. B. L. Peterson. and H. 1. Smith. 1975, The origin of Red Mountain regIOn, U.S.A.: Rocky Mountain Assoc. Geologists, p. Wing Creek structure: McKenzie County, North Dakota: Wyoming 90-100 Oeo!. Assoc. Earth Sci. Bull., v. 8.41 p. Ballard, F V. 1963, Structural and stratigraphic relationships in the upper Bridges, L. W. D .• 1978. Red Wing Creek field, North Dakota; a concen Paleozoic rocks of eastern Nonh Dakota: Nonh Dakota Geo!. Survey triciine of structural origin. in The economic geology of the Williston Bull. 40, 42 P basin: Williston Basin SYOlpo~ium. Montana Oeol. Soc., p. 315-326. BJorlic, P. E. 1979. The Carrington Shale facies (Mississippian) and its Brown. D. L., 1978. Wrench-style deformational patterns associated with relationship to the Scallion subinterval in central Nonh Dakota: North a meriodional Slres.~ aXIs recognized in Paleozoic rocks in parts of DakOla Geol. Survey Rept. rnv. 67,46 P Montana. South Dakota, and Wyoming, in The economic geology of ~--and S. B. Anderson, 1978, Stratigraphy and depositional setting of the Williston basin: Williston Basin Symposium. Montana Oeol. Soc., the Carrington Shale facies (Mississippian) of the Williston basin. in p. 17-35 The economic geology of the Williston basin: Williston Basin Sym BurchfieJ. B. C. and J. H. Stewart, 1966. "Pull-apart" origin of the posium, MontanaOeol. Soc., p. 165-177. central segment of Death Valley, California: Oeo!. Soc. America Bluemlc. J. P., S. B. Anderson, and C. O. Carlson, 1980, North Dakota Bull., v. 77, p. 439-442 . A .. -:}~.. _... _... _....- ... ::::: "" Belt At. '",.. ..:.:....:. "\,Super:group ""'l:~ y'" Pt. of Williston Bosin "::, ...... ~T~ )0 .:.:....::. )-..L'" ..? ..L?.... ,J.,). ::·.Y , ::-.t:. Central Montano Embayment .j:~·!:k~ " .•::':':';':'f.::.•':'.i. .a."" Uinta Mountain Group //j2@;ifj;'~:~~:uar Group PuhrumP':~:::·.::::'::''''' to'" GrouP,:.-f.::·:.:.::;:: .. ." ::••:.:.....::...... :.:: .( T "" of ApaChe Group TREND OF UPPER PRECAMBRIAN ~/;!>:. EZJ AND LOWER CAMBRIAN ROCKS o lQO 3QO MILES .... { Ii. , o 100 100 KILOM£T£ ItS B k:::::;:J AREA OF TE NS ION N CENTRAL ROCKY MOUNTAINS FIG. 25-A. Aulacogen origin for ,",,'illiston basin. Basin is shown as possible extension of Central Montana embayment dUring Pre cambrian time. Modified from Stewart (1972). B. Pull-apart origin for Williston basin. Basin was placed under tension due to move ment along major shear zones causing grabenlike downdropped blocks. Modified from Burchfiel and Stewart (1%6). Lee C. Gerhard et al 1015 50.000 40.000 40,338 Ul ...J W a: a: « tD 30,000 o o Q 23,273 20.000 I INESSON-MADISON I J l LITTLE KNIFE, RED WING OPEC MONOAK MADiSON STRATIGRAPHIC CREEK BOTTINEAU-BURl 10,000 ORIGINAL DISCOVERY N ~ • ~ ~ ~ ~ ~ 0 _ N ~ .. ~ ~ ~ CDO\O-N"". "'~""Q)cno ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ w ~ ~ w ~ ~ cQ w ~ ...... t-- ...... CD ~ ~ ~ YEARS FIG. 26-Annual oil production in North Dakota, 1951·80 (in 1,000 bbl). See text for discussion of events on graph. eo ~ • ~ ~ • ,o ~ ~ " ~ g ~ ~ ~ l' ~ ~• ~ '0 c -~ w < •~ u ~ · ~ ~ w 0; , > ,~ ~ • ·o • ~ ~ 30 ~ ~ a " "~ "< ~ g" . '00 J • < "0 ~ 20 ~ z i 1\ ) " rv/ 00 ~/J \~Av\/~ ~r-r"~I-'----'--'-·""""-'--'T-ITII ;~:i:;:i~~:;::;;;Q~'3~~~:O~~~.;:;,:~::,~::-~::,* o Iii I f i i r I\III I II i I I I I i I I I I I I I I YE.4RS nG. 27-Graph showing number of wildcat wells, 1951 FJG. 28--Graph showing number of new pool discoveries. through 1980. 1951 to 1980. The 1980 number is 55 discoveries. 1016 Williston Basin, North Dakota .!II'_ .. - . Carlson. C. G., 1960, Stratigraphy of the Winnipeg and Deadwood For p8~T~~"E:~U "", ." mations in North Dakota: North Dakota Geol. Survey Bull. 35, 145 p . ~,!~:" • II --- and S. B. Anderson. 1966. Sedimentary and tectonic history of I 1'0°"'" . ' .,. . .' North Dakota part of Williston basin: AAPG Bull., v. 49. p. 1833 I, ~ 1846. , Carroll, W. K.. 1979. Depositional environments and paragenetic porosity WILLIAMS .. ~ controls. opper Red River Formation, North Dakota: North Dakota l Me HENRY! U Geol. Survey Rept. Inv. 66, 51 p. MOU NTRAIL WAR 0 V. • --- and L. C. Gerhard. 1979. Dolomitization in upper Red River .~. , • Formation (Upper Ordovician). North Dakota (abs.): AAPG Bull., v. 63, p. 430. t·· Clark, T. H., and C. W. Stern, 1968. Geologic evolution of North Me KENZIE : MC~E:AN .. America: New York, Ronald Press. 570 p . SHERIDAN Clemen!, J. H., 1976, Geologic history~key to accumulation al Cedar , Creek Cabs.); AAPG BUll., v. 60, p. 2067·2068 o UN N ---. and T. E. Mayhew, 1979, Newpone discovery opens new pay: Oil ,. , and Gas Jour.. v. 77, no. 27. p. 165-172. ~ " Craig. L. C., 1972. Mississippian System, in Geologic atlas of the Rocky ~" el~lIN~~ { Mountain region, U.S.A.: Rocky Mountain Assoc. Geologists, p. HXl-III . 2 ., ~ S TAR K Donofrio, R. R.• 1981, Jmpact craters; implications for basement hyd a .. g I .. I I rocarbon production: Jour. Petroleum Geology, v. 3. no. 3, p. 279 302. Dow. G., 1974, Application of oil correlation and source-rock data to S LOP HETTINGER W. exploration in Williston basin: AAPG Bull.. v. 58, p. 1253-1262. G R A NT ------r----~ ,)+ OMMOfliSI Estelle, D.• and R. Miller, eds., 1978, Economic geology of the Williston BOWMAN I 0 basin: Williston Basin Symposium, Montana Geo!. Soc .. 447 p_ " A 0 A M S ~ _ Foster, N. H.• 1972, Ordovician System, in Geologic atlas of the Rocky Mountain region. U.S.A.: Rocky Mountain Assoc. Geologists, p. 76-86. o, 50 100, IIIILES Fuller, J. G. C. M., 1961, Ordovician and contiguous formations in North Dakota, South Dakota, and Montana: AAPG Bull., v. 45, p. 1334 FIG, 29-Producing fields in North Dakota, 1970, 1363. . ,~~,-. ' D I V IDE , ... o ... .-.T~E. • : . " If' " ~ ", MCHENRY • u WAR 0 u Me HENRY • w A II 0 ~ • ~ • • ~ C MCLEAN SHERIDAN' MCLEAN SHERIDAN , o • • ~ ," • . Jfu N N • ~ DU-' • f: " ~•.' !! BllUNGSo 0 ~ ...... : .",., ~ ~ ~ STARK' .. s" TAR K ~.o .' --"-----l, • HETTINGER S LOP E ETTINGE R + EMMONS -fe-poll! Butit' EM MO "IS ~ ~ BOW~AN o , B a,..W t:I ..A N ".. . A 0 A '" S , A DAM S o ~o 100 IlILU , I A- New field discoveries for 1980 * Apparent new discovery FIG. 3D-Producing fields in North Dakota, 1980. Note large number of new fields in western North Dakota south and west of Nes~ son anticline. Lee C. Gerhard etaf 1017 Gerhard, L. C" and S. B. Anderson. 1979. Oil exploration and develop Groenewold. G. H., 1979, Active and proposed lignite mines and related ment in North Dakota Williston basin: North Dakota Oeo!. Sun'ey consuming facilities in western ~orth Dakota: North Dakota Geo!. Misc. Series57.19p. Survey Misc. Map 20. ------1981. Oil exploration and development in the North Harris, K_ L., et al. llJ&l, An evaluation of hydrothermal resources of Dakota Williston basin; 1980 update: \forth Dakota GeoL Survey North Dakota; phase II final technical report: Univ. North Dakota Misc. Series 59. 19p. Engineering E"perimem Stalion l:IulL MI-05-EES-02. ------and j. Berg. 1978, Mission Canyon porosity development. Heck, T., 1978, Depositional environments of Ihe Botlineau interval Glenburn field. North Dakota, Williston Basin, in The economic (Lodgepole) in North Dakota, in The Economic geology of the geology of the Williston basin: Williston Basin Sympo<;.ium, Montana Williston basin: WiIli!i.ton Basin Symposium. Montana Geol. Soc_. P Geol Soc" p. 177-189 191-203. Grenda. J. C, 1978. Paleozoology of oil well cores from the Tyler Hoganson, 1. W.• 197M. Microfacies analysis and depositional environ Formation (Pennsylvanian) in North Dakola, U.S.A., in The eco ments of the Dupcrow Formation (Frasnian) in the North Dakota part nomic geology of the Williston basin: Williston Basin Symposium. of the Williston basin. in The economic geology of the Williston basin: Montana Geol. Soc., p. 249-263. Williston Basin Symposium, Monlana Geol. Soc., p_ 131-144. PRAIRIE SALT ISOPACH ~-- --,r __ I ~\' ~ , --. SASKATCHE 'ill"",~_", " '--"'" -- " -,_ _ W~N MANITOBA f -k: OA" <',"O'~ , ' -,_ ' '' I '' ,,,.r -- I ••\ \ , , " ,'"I '-,' I':',',", ... \'" ".~II' O, ...... \ <'c:b ,I"' I'I '",,''= 0 I' ... - ~,,." \' ' ' ,,,-. ., IJ>' .',::;~,l_ __ ,J ,,~I ,r. I 'l; "I:; ", '.:' 1lOU ,I , I "'"'V I 9:~ ,,~ , ~-,'~ I-b \...... , ,,...,.,,' 't · ",' " ' , I l.lU I I}& ... ,~I __ ,------"-' c(/ I ' I " ., \ '_. '" :\ \ ,,0 / //~ \ oJ • 1\ \ " f ,." ...... " ,, I \ \ '... "0',,' I ,' "r' ... ' ' ... _ .. ' 0 ' ",g ,...... - ,'1;' I 1 , 'VO ---.',' I N '., ..... 0>' I I ...... ~ " '...... ", ",,0 l ...... - , .. "" I..~'" ----,... " ..." ,_ ... " ~~te.'Y ·',i,...... ,," ".....0'< '0 0 10 20 30 ~ MU.ES 0' ..... -- .. "'; ,,~t I It, I , , " I DI"on\O 10 0 '0 20 30 40 KILOMETERS CONTOUR INTERVAL 100ft MONTANA I NORTH DAKOTA FIG. 31-lsopach map of Prairie salt in Montana and North Dakota, showing limit of Prairie salt. Modified from Anderson and Swinehart (1979)_ w E DANIELS l:Ol.t1lTY MONTANA ' &OTTINEA..., COUNTY, "IORTtt [W(()TA hl~ Plo;n, _ ..' . "._ _ __ lrail Mtlllber \ Top of Ptairil ~::,·~.T .~cc..""" ~.;::;? I~m."~ ...... MoM'" l!PY~_-&IL - _....~mber EIlerhot1 »,"'h, IJ' .--'"""- ----.... S'lil .--/ filS.! ;,!.--.--.- Do'''''' Top 01 !~~ P,a r>e FOl",ol,on " 200 Fft' I " '---'0 "I,'" OJ()~TH Dhor ... IOTAe I<£S(I""C[:"> 50illU,O.. '0"15 FIG. 32-Cross section from Daniels County, Montana, through Bottineau County, North Dakota, showing potash beds within Prai rie Formation. Shaded zones are potash bearing. Modified from Anderson and Swinehart (1979). 1018 Williston Basin, North Dakota Kearns, J. R.. ana 1. D. Tl I j the Rocky Mountain region, U.S.A,' Rocky Mountain Assoc co'; • N t S,,,ppab1e Geologl~l, I,gn. Ie don" p. 143·166. epoS'ls Roehl, P., 1967, Carbonate facies, Williswn basin and Bahamas: AAPG I 50 Bull., v. 51, p. 1979·2033. J oI ! Iqo Miles f---- - Ross. R. J., Jr., 1957, Ordovician fossils from wells in the Williston basin, ea~lern Montana: U.S, Gco!. Survcy Bull. 1021-M, P 439-510. FIG. 3.l-Map showing distribution of strippable coal depos Scott. M. W., 19SI, Annotated bibliography of the geology of North its in Williston and Powder River basins of North Dakota, Dakota, 1960-1979: North Dakuta Geol. Survey Misc. Series 60. 287 Montana, and Wyoming. Modified from USGS Miscellaneous p Map MF·540 (\974). F"';:;l ~~~~lr~~\RBEUE~TE f'.:·~··~~1 CANNONBALL E======l SLOPE _LUDLOW 6090 A 5029 5030 Al 7094 :.... ..;,;,;;,;.: .•..~ ...... ,;",;.::;.;:;----. :o:...... ;",:.:~...... TC ••~••- •••--o- • 4815 .--_-_-_-_-_-_-t-_-_-_-_~_-_-_-_-_-_~_------~-~-----~------ - -- - -- - - ------ ----------~------~ -:-:-:-:-:-:; -:-:-:-?-:: ==: ------ - - - ------ , ~ r,c:.::.~.::~~»~::~;{;;.;.:~:}}t'< :~~?~~~kffr}::.:~ Ii;IIrtJ ;.~. !~""i.':;":., ... ~: :.:.... L' ~,. . tJ RESOURCES 350 BILLION TONS RESERVES 20 BILLION TONS FIG. 34-Diagrammatic cros.\ section of Paleocene rocks in western North Dakota showing relationship of lignite beds and stratia graphic units. Numbers at vertical dark lines refer to North Dakota Geological Survey drill·hole control. Lee C. Gerhard et al 1019 ® Known slriPflQblt lignite deposits '='~ ..o 3 ~ Area of known, but less well deposi~ ,~ ?i5 defined lignite =:j Llmil olllonite-beor...o stratD "'t) "= .~ ~ • ExislinQ ''9'1It. "I"P m,ne ~ o Proposed lIOnlte striP mine ~ ~-" ~ EIUstioQ electric poww okJnt -'2..., 1lD ~, & Proposed electnc power plonI = .ci. ~ cool OGSlif,coOOn~. ~ ~ ~ ,,1 =:?~ II 0ItMr fOC~il1 uftIllino lignite <::::7«' -c:.::" -~ ~ /l---, {J) = , = N V"'-J c::::::7 ~ v~o ~'W .~ " c:sr ~ f!)'fR ~:~ 0>i'~' , ~ c';; ~: .:i\. ~::z:v~ o/t, '.'.~<, .c;" ,<' • _,,0 ,----J " J/I0/ 'iI ~i - (;S) i? .OJ' ~CJ II O. HG. 35-Map showing strippabte lignite deposits and development areas of lignite in North Dakota. Note heavy concentration of active or proposed usage of lignite northwest of Bismarck. Modified and redrawn from Groenewold (1979). COAL PRODUCTION l> X> 14,279 ,. '0 " ~- ~ ~ " 0 11., D ~ " o 0 ) ~ .' r~ o , ) ~7056 " ~ "~ 6, ~ r ~ ) ~ o ' ~ "-. ~~ 2~'" ~ ).00 '2522 2557 ~ 2,520 2,520 '2 758 .' , .' , 960 I 196 962 I '963 I 196 l'il65 I 1966 I 1967 I 1968 I 1969 1 1970 I 19'71 I 1972 I 19731 1974 I 197!1 1 1976 I '977 I '~'8 I U79 FISCAL YEARS FIG. 36--Graph showing production of coal (lignite) in North Dakota 1960·79. Note steady increase ill production from 1966 to 1974 with jump in 1976 and additional increases following. The increases in 1976-79 apparently reflect increasing demand for electrical generation replacing other sources of energy. 1020 Williston Basin, North Dakota Slo~~. L. L . 1963, Sequence;; in the cratOnic intenor of North America Warner. L. A., 1978, The Colorado lineament: a middle Precambrian Geol. Soc. America Bull., v. 74, p. 93-114 wrench fault system: Ceol. Soc Amenca Bull., v, 89, p. 161-171. Stewart, J. H., 1972, Initial deposits in the Cordilleran geosyncline: Williams. J. A .. 1974. Characterilation of oil type:. in the Williston basin: evidence of a late Precambrian (850 m.y.) continental separation: AAPG Bull.. v. 58. p. 1243-1252. Geol. Soc. America Bull., v. 83, p. 1345-1360. Worsley, N., and A. Fuzesy, 1978, The potash-bearing members of fhe Thomas. G. E., 1974, Lineament-block tectonics; Williston-Blood Creek Devonian Prairie evaponte of southeaslern Saskatchewan south of the Basin: AAPG Bull., v. 58. p. 1305-1322. mining area, In Economic geology of the WillJ~ton basin: Williston U.S. Geological Survey, 1974, Stripping coal deposits of the Northern Basin Symposium. Montana GeoJ. Soc., p. 153-165. Greal Plains, Montana, Wyoming, North Dakota, and South Dakota: Ziebarth. H. c.. 1964. The Tyler Formation of southwestern North U.S. Geol. Survey Misc. Fields Sludie;; Map MF-590. DakOla: 3d Infernal. Williston Basin Symposium, p. 119-126.