DOCSLIB.ORG

Lower Ellis Group (M. Jurassic), Wyoming and Montana, U.S.A

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Lower Ellis Group (M. Jurassic), Wyoming and Montana, U.S.A Sedimentary Geology 177 (2005) 175–194 www.elsevier.com/locate/sedgeo Mixed sediment deposition in a retro-arc foreland basin: Lower Ellis Group (M. Jurassic), Wyoming and Montana, U.S.A. William C. ParcellT, Monica K. Williams Department of Geology, Wichita State University, 1845 Fairmount, Box 27, Wichita, KS 67260-0027, USA Received 28 January 2004; received in revised form 17 January 2005; accepted 25 February 2005 Abstract The blowerQ Ellis Group (M. Jurassic) of northern Wyoming and southern Montana affords an excellent opportunity to examine the influence of tectonics, sea-level change, and incipient topography on facies dynamics and the evolution of mixed sediment ramp deposits. The Sawtooth, Piper, and Gypsum Spring formations (Bajocian to Callovian) represent sedimentation along the forebulge of a retro-arc foreland basin. The blowerQ Ellis Group records deposition during two transgressive– regressive cycles, (1) a Bajocian-age cycle dominated by evaporites and red shales, and (2) a Bathonian-age cycle characterized by carbonates, evaporites, and red shales. These cycles are capped by a Callovian-age cycle distinguished by carbonates and red shales that is represented by the blowerQ Sundance and Rierdon Formations. Transgressive episodes favored intensified chemical sediment production resulting in thick units deposited in subtidal to peritidal environments. Regressive periods are characterized by supratidal redbed progradation and subsequent shallowing–upward cycles. The depositional cycles in the lower Ellis Group developed due the interplay between sea-level change and tectonic subsidence related to the evolution of a retro-arc foreland basin. Differential subsidence before, during, and after deposition created paleohighs that locally influenced accommodation space and, thereby, complicated depositional and erosional patterns. This paper provides a regional framework for further analysis of the depositional history of the lower Ellis Group by addressing the stratigraphic relationships between the Sawtooth, Piper, and Gypsum Spring Formations. D 2005 Elsevier B.V. All rights reserved. Keywords: Clastic; Carbonate; Evaporite; Sequence stratigraphy; Jurassic 1. Introduction changes in a relatively predicable manner (Burchette and Wright, 1992; Azeredo et al., 2002). Although the Mixed siliciclastic and chemical deposits in ramp controls on depositional facies patterns in passive settings have been shown to respond to sea-level systems are well documented, there are few published studies of the effects of local tectonic movements on mixed sediment depositional systems. However, this T Corresponding author. situation is recorded during the Middle Jurassic in the E-mail address: [email protected] (W.C. Parcell). Western Interior of the United States where local 0037-0738/$ - see front matter D 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.sedgeo.2005.02.007 176 W.C. Parcell, M.K. Williams / Sedimentary Geology 177 (2005) 175–194 tectonic movements related to the evolution of a retro- character of the Middle Jurassic section. However, arc foreland basin influenced depositional and ero- Kilbarda and Loope (1997) and Kvale et al. (2001) sional patterns in a restricted ramp setting. have recently demonstrated that certain beds within This paper presents a depositional model to the Sundance and Gypsum Spring Formations are also examine the influence of tectonics, sea-level change, lagoonal to terrestrial in origin owing to the identi- and incipient topography on facies dynamics and fication of aeolian limestone and dinosaur tracks. evolution of the mixed sediment Sawtooth, Piper, and Lithologies in the lower units of the Ellis Group Gypsum Spring formations. This is achieved using vary widely depending on location in the basin and lithofacies distribution, bounding surfaces, and bio- their position relative to paleostructures. The Saw- stratigraphic zones within a sequence stratigraphic tooth Formation in western Montana varies between framework. limestone, dolomite, shale, siltstone, and sandstone. Cobban (1945) divided the Sawtooth Formation into three units: (1) a basal sandstone/siltstone unit, (2) a 2. Geologic setting middle limestone/shale unit, and (3) an upper shale/ siltstone unit. Lithologies in southern and eastern The early Mesozoic was a time of great change for Montana are dominated by carbonates and evaporites. western North America as the continental margin For these reasons, Imlay et al. (1948) defined the evolved from largely passive depositional systems Piper Formation from exposures near Lewiston, during most of the Paleozoic to tectonically-active Montana. The Piper is divided into three units (this basins in the early Mesozoic. A major shift in plate time given formal member status): (1) Tampico Shale motions resulted in highly oblique convergence Member, (2) Firemoon Limestone Member, and (3) between the ancestral Pacific plates and the North Bowes Member (Nordquist, 1955). The Gypsum American plate (Fig. 1). This intersection resulted in Spring Formation of Wyoming is also informally complex compressional, tensional, and transtensional divided into three major lithologic units based on forces, which produced a wide variety of depositional lithology and regional continuity of strata. The basal settings across the western North American plate unit contains predominantly white, massive gypsum including passive margin coastal plains to active or anhydrite with interbedded noncalcareous red shale margin mountains, arcs, and tectonic basins (Blakey, and siltstone. The middle unit contains interbedded 1997). The Middle and Upper Jurassic deposits of green–gray to varicolored shales and gray, black, and Wyoming and Montana record at least four major brown limestones. The informal upper unit contains transgressive–regressive marine inundations related to primarily red to gray shale and siltstone. the development of a retro-arc foreland basin that was connected to the proto-Pacific Ocean (Fig. 1)(Peter- 2.1. The correlation quandary son, 1954; Brenner and Peterson, 1994). With the onset of thrust faulting during the Middle Jurassic, a Before discussion of the depositional evolution of foredeep developed in present-day Utah and eastern the blowerQ Ellis Group, the enduring problem of Idaho depositing the Twin Creek Formation. To the stratigraphic correlation of these units must be east of this trough, the foreland basin was charac- addressed. Two fundamental challenges persist. First, terized by a ramp margin along the western edge of a there is inconsistent use of the names bGypsum cratonic forebulge (Fig. 2). Spring FormationQ and bPiper FormationQ because Sediments deposited on this forebulge are repre- their formal type sections are recognized as incom- sented in northern Wyoming by the Gypsum Spring plete and not representative of the units across much Formation, blowerQ Sundance Formation, and bupperQ of Wyoming and Montana (Rayl, 1956; Meyer, 1984; Sundance Formation. In southern Montana, the cycles Williams, 2003).ThetypesectionofthePiper correspond to the Sawtooth Formation, Piper For- Formation near Lewiston, Montana, as defined by mation, Rierdon Formation, and Swift Formation Imlay (1948) represents only the upper third of the (Fig. 3). Early interpretations by Cobban (1945) and units that are commonly referred to as the Piper Peterson (1955) emphasized the shallow marine Formation elsewhere in Montana (Rayl, 1956). The W.C. Parcell, M.K. Williams / Sedimentary Geology 177 (2005) 175–194 177 SIBERIA NORTH EUROPE AMERICA AFRICA SOUTH AMERICA INDIA ANTARCTICA AUSTRALIA Proto-Pacific Ocean volcanic is Figure 2 lands transf land orm z shallow shelf one deep marine subduction zone thrust front (M. Jurassic) Fig. 1. Regional Middle Jurassic paleogeography of the western North America. The early Mesozoic convergence between the ancestral Pacific plates and the North American plate produced a wide variety of depositional settings across the western North American plate including passive margin coastal plains to active margin mountains, arcs, and tectonic basins. The blowerQ Ellis Group was deposited in an epicontinental sea related to the development of a retro-arc foreland basin (modified from Blakey and Umhoefer, 2003; Allen et al., 2000). 178 W.C. Parcell, M.K. Williams / Sedimentary Geology 177 (2005) 175–194 Belt Williston Jurassic Basin Island iv Middle Middle ii rough rding T A during HHardina g rch iii n ArchA rida i She thrustin h A' g limit of u ouo rn r T k easte e e r land C ximate n i w T shallow shelf appro deep marine A A' fold-thrust wedge belt top foredeep forebulge iiiiii iv Sheridan Arch Twin Creek Trough active retro-arc foreland basin Harding Trough Fig. 2. Paleogeography of study area with generalized cross-section across retro-arc foreland basin (A–AV). Twin Creek Formation (i) was deposited within the western foredeep and the Sawtooth Formation (ii), Gypsum Spring Formation (iii), and Piper Formation (iv) represent deposition across the shallow foredeep and forebulge. Stratigraphic comparison of these formations is examined in Fig. 3. type section of the Gypsum Spring at Red Creek in the van (1978) and O’Sullivan and Piperingos (1997) Owl Creek Mountains, as defined by Love (1939, recognized regional unconformities by these chert 1945), is also incomplete. The Red Creek section lags and named them J-0, J-1, J-2, J-3, and J-4 (Fig. represents only the lower third of the section that is 1). These horizons have been widely reported commonly identified as the
Load more

Recommended publications
  • Morrison Formation 37 Cretaceous System 48 Cloverly Formation 48 Sykes Mountain Formation 51 Thermopolis Shale 55 Mowry Shale 56
    THE STRUCTURAL AND STRATIGRAPHIC FRAMEWORK OF THE WARM SPRINGS RANCH AREA, HOT SPRINGS COUNTY, WYOMING By CHRISTOPHER JAY CARSON Bachelor of Science Oklahoma State University 1998 Submitted to the Faculty of the Graduate College of the Oklahoma State University in partial fulfillment of the requirements for the Degree of MASTER OF SCIENCE July, 2000 THE STRUCTURAL AND STRATIGRAPHIC FRAMEWORK OF THE WARM SPRINGS RANCH AREA, HOT SPRINGS COUNTY, WYOMING Thesis Approved: Thesis Advisor ~~L. ... ~. ----'-"'-....D~e~e:.-g-e----- II ACKNOWLEDGEMENTS I wish to express appreciation to my advisor Dr. Arthur Cleaves for providing me with the opportunity to compile this thesis, and his help carrying out the fieldwork portion of the thesis. My sincere appreciation is extended to my advisory committee members: Dr. Stan Paxton, Dr. Gary Stewart, and Mr. David Schmude. I wish to thank Mr. Schmude especially for the great deal of personal effort he put forth toward the completion of this thesis. His efforts included financial, and time contributions, along with invaluable injections of enthusiasm, advice, and friendship. I extend my most sincere thank you to Dr. Burkhard Pohl, The Big Hom Basin Foundation, and the Wyoming Dinosaur Center. Without whose input and financial support this thesis would not have been possible. In conjunction I would like to thank the staff of the Wyoming Dinosaur Center for the great deal of help that I received during my stay in Thermopolis. Finally I wish to thank my friends and family. To my friends who have pursued this process before me, and with me; thank you very much.
    [Show full text]
  • Petroleum Geochemistry of the Lower Cretaceous
    Petroleum Geochemistry of the Lower Cretaceous Mannville and Jurassic Ellis Groups, Southern Alberta, Canada Kim Manzano-Kareah *, Shell International Exploration and Production, Houston, USA [email protected] The variation of oil quality in southern Alberta, Western Canada Sedimentary Basin, Canada is primarily due to differences in oils generated from different source rocks and biodegradation of oils in reservoirs. 280 oil samples were collected and analysed by GC and GC-MS, in order to assess the nature and extent of these petroleum systems. Oils from Lower Cretaceous Mannville and Jurassic Ellis Group reservoirs in southern Alberta, Canada (T1-40; R1-25W5) were generated from at least five different source rocks. The proven/probable source rocks include: the Devonian Duvernay Formation (Family D), the Devonian-Mississippian Exshaw Formation (Family E), a probable Paleozoic source (Family M), a probable Jurassic source (Rierdon/Fernie shales; Family F), and the Cretaceous Ostracod Zone (Family Q). Family D oils are restricted to the northernmost part of the study area (Provost field). Biodegradation and the mixing of degraded with non-degraded oils are the main factors controlling the variation in oil quality within a given family. The much improved understanding of oil families and degree of biodegradation allow for more accurate mapping of likely oil migration pathways. Known reservoir trends, subcrop edges, structure, hydrodynamics, the distribution and quality of known oil pools can all be integrated into mapping migration paths. This allows for more accurate mapping of likely oil and gas migration pathways, which can be used for prospect risking and for the ranking of exploration plays.
    [Show full text]
  • Geology and Petrology of the Devils Tower, Missouri Buttes, and Barlow Canyon Area, Crook County, Wyoming Don L
    University of North Dakota UND Scholarly Commons Theses and Dissertations Theses, Dissertations, and Senior Projects 1980 Geology and petrology of the Devils Tower, Missouri Buttes, and Barlow Canyon area, Crook County, Wyoming Don L. Halvorson University of North Dakota Follow this and additional works at: https://commons.und.edu/theses Part of the Geology Commons Recommended Citation Halvorson, Don L., "Geology and petrology of the Devils Tower, Missouri Buttes, and Barlow Canyon area, Crook County, Wyoming" (1980). Theses and Dissertations. 119. https://commons.und.edu/theses/119 This Dissertation 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]. GEOLOGY AND PETROLOGY OF THE DEVILS TOWER, MISSOURI BUTTES, AND BARLOW CANYON AREA, CROOK c.OUNTY, WYOMING by Don L. Halvorson Bachelor of Science, University of Colorado, 1965 Master of Science Teaching, University of North Dakota, 1971 A Dissertation Submitted to the Graduate Faculty of the University of North Dakota in partial fulfillment of the requirements for the degree of Doctor of Philosophy Grand Forks, North Dakota May 1980 Th:ls clisserratio.1 submitted by Don L. Halvol'.'son in partial ful­ fillment of the requirements fo1· the Degree of Doctor of Philosophy from the University of North Dakota is hereby approved by the Faculty Advisory Committee under whora the work has been done. This dissertation meets the standards for appearance aud con­ forms to the style and format requirements of the Graduate School of the University of North Dakota, and is hereby approved.
    [Show full text]
  • Carboniferous Formations and Faunas of Central Montana
    Carboniferous Formations and Faunas of Central Montana GEOLOGICAL SURVEY PROFESSIONAL PAPER 348 Carboniferous Formations and Faunas of Central Montana By W. H. EASTON GEOLOGICAL SURVEY PROFESSIONAL PAPER 348 A study of the stratigraphic and ecologic associa­ tions and significance offossils from the Big Snowy group of Mississippian and Pennsylvanian rocks UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1962 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director The U.S. Geological Survey Library has cataloged this publication as follows : Eastern, William Heyden, 1916- Carboniferous formations and faunas of central Montana. Washington, U.S. Govt. Print. Off., 1961. iv, 126 p. illus., diagrs., tables. 29 cm. (U.S. Geological Survey. Professional paper 348) Part of illustrative matter folded in pocket. Bibliography: p. 101-108. 1. Paleontology Montana. 2. Paleontology Carboniferous. 3. Geology, Stratigraphic Carboniferous. I. Title. (Series) For sale by the Superintendent of Documents, U.S. Government Printing Office Washington 25, B.C. CONTENTS Page Page Abstract-__________________________________________ 1 Faunal analysis Continued Introduction _______________________________________ 1 Faunal relations ______________________________ 22 Purposes of the study_ __________________________ 1 Long-ranging elements...__________________ 22 Organization of present work___ __________________ 3 Elements of Mississippian affinity.._________ 22 Acknowledgments--.-------.- ___________________
    [Show full text]
  • Evidence of Pachyostosis in the Cryptocleidoid Plesiosaur Tatenectes Laramiensis from the Sundance Formation of Wyoming Hallie P
    Marshall University Marshall Digital Scholar Biological Sciences Faculty Research Biological Sciences 2010 Evidence of pachyostosis in the cryptocleidoid plesiosaur Tatenectes laramiensis from the Sundance Formation of Wyoming Hallie P. Street Marshall University F. Robin O’Keefe Marshall University, [email protected] Follow this and additional works at: http://mds.marshall.edu/bio_sciences_faculty Part of the Animal Sciences Commons, and the Ecology and Evolutionary Biology Commons Recommended Citation Street, H. P., and F. R. O’Keefe. 2010. Evidence of pachyostosis in the cryptocleidoid plesiosaur Tatenectes laramiensis from the Sundance Formation of Wyoming. Journal of Vertebrate Paleontology 30(4):1279–1282. This Article is brought to you for free and open access by the Biological Sciences at Marshall Digital Scholar. It has been accepted for inclusion in Biological Sciences Faculty Research by an authorized administrator of Marshall Digital Scholar. For more information, please contact [email protected], [email protected]. EVIDENCE OF PACHYOSTOSIS IN THE CRYPTOCLEIDOID PLESIOSAUR TATENECTES LARAMIENSIS FROM THE SUNDANCE FORMATION OF WYOMING HALLIE P. STREET and F. ROBIN O'KEEFE; Department of Biological Sciences, Marshall University, One John Marshall Drive, Huntington, West Virginia 25755, U.S.A., [email protected], [email protected] INTRODUCTION In this paper we present evidence for pachyostosis in the cryptocleidoid plesiosaur Tatenectes laramiensis Knight, 1900 (O'Keefe and Wahl, 2003a). Pachyostosis is not common in plesio- saurs and is particularly rare in non-pliosaurian plesiosaurs, although enlarged gastralia were first recognized in Tatenectes by Wahl (1999). This study aims to investigate the nature of the dispro- portionately large gastralia of Tatenectes m greater depth, based on new material.
    [Show full text]
  • Quiz 12 Bonus 2 (9:30-9:35 AM) UNIVERSITY of SOUTH ALABAMA
    Quiz 12 Bonus 2 (9:30-9:35 AM) UNIVERSITY OF SOUTH ALABAMA GY 112: Earth History Lectures 32 and 33: Mesozoic Sedimentation Instructor: Dr. Douglas W. Haywick Last Time Mesozoic Tectonics A) The Triassic B) The Jurassic C) The Cretaceous (web notes 31) Mesozoic Tectonics Tectonics in North America during the Mesozoic was dominated by docking events involving terranes. Ultimately, continents grow bigger by scooping up geo-crap in their drift direction (Accretionary tectonics) Sonoman Orogeny Mesozoic Tectonics Into the Triassic, many more “terranes” (mostly island arcs) began to be scooped up by North America as it drifted WNW •Brooke Range Terrane (Alaska) •Stikine Terrane (British Columbia) •Sonoma Terrane (Nevada) Mesozoic Tectonics In the Jurassic, we start to see terranes with mixed lithologies docking with North America (e.g., Klamath Terrane) •Major (felsic) intrusions begin Mesozoic Tectonics In the Cretaceous, more hits and more intrusions. More uplift •Wrangellia Terrane docks What’s the Point? The Appalachians and Cordilleran Mountains were both formed via compressional tectonic events. Appalachians formed through collisions with other continents Cordilleran Mts. formed via accretionary tectonics Today’s Agenda Mesozoic Sedimentation A) Triassic Sedimentation (Breakup of Pangaea) B) Jurassic Sedimentation (Birth of the Atlantic Ocean) C) Cretaceous Sedimentation (Creation of the Coastal Plain Province) D) Mesozoic-Cenozoic climate (Greenhouse-Icehouse Earth Transition) (web notes 32) Mesozoic Paleogeography Mesozoic Sedimentation
    [Show full text]
  • Appendix 1 – Environmental Predictor Data
    APPENDIX 1 – ENVIRONMENTAL PREDICTOR DATA CONTENTS Overview ..................................................................................................................................................................................... 2 Climate ......................................................................................................................................................................................... 2 Hydrology ................................................................................................................................................................................... 3 Land Use and Land Cover ..................................................................................................................................................... 3 Soils and Substrate .................................................................................................................................................................. 5 Topography .............................................................................................................................................................................. 10 References ................................................................................................................................................................................ 12 1 OVERVIEW A set of 94 potential predictor layers compiled to use in distribution modeling for the target taxa. Many of these layers derive from previous modeling work by WYNDD1, 2, but a
    [Show full text]
  • A Preliminary Assessment of Paleontological Resources at Bighorn Canyon National Recreation Area, Montana and Wyoming
    A PRELIMINARY ASSESSMENT OF PALEONTOLOGICAL RESOURCES AT BIGHORN CANYON NATIONAL RECREATION AREA, MONTANA AND WYOMING Vincent L. Santucci1, David Hays2, James Staebler2 And Michael Milstein3 1National Park Service, P.O. Box 592, Kemmerer, WY 83101 2Bighorn Canyon National Recreation Area, P.O. Box 7458, Fort Smith, MT 59035 3P.O. Box 821, Cody, WY 82414 ____________________ ABSTRACT - Paleontological resources occur throughout the Paleozoic and Mesozoic formations exposed in Bighorn Canyon National Recreation Area. Isolated research on specific geologic units within Bighorn Canyon has yielded data on a wide diversity of fossil forms. A comprehensive paleonotological survey has not been previously undertaken at Bighorn Canyon. Preliminary paleontologic resource data is presented in this report as an effort to establish baseline data. ____________________ INTRODUCTION ighorn Canyon National Recreation Area (BICA) consists of approximately 120,000 acres within the Bighorn Mountains of north-central Wyoming and south-central Montana B (Figure 1). The northwestern trending Bighorn Mountains consist of over 9,000 feet of sedimentary rock. The predominantly marine and near shore sedimentary units range from the Cambrian through the Lower Cretaceous. Many of these formations are extremely fossiliferous. The Bighorn Mountains were uplifted during the Laramide Orogeny beginning approximately 70 million years ago. Large volumes of sediments, rich in early Tertiary paleontological resources, were deposited in the adjoining basins. This report provides a preliminary assessment of paleontological resources identified at Bighorn Canyon National Recreation Area. STRATIGRAPHY The stratigraphic record at Bighorn Canyon National Recreation Area extends from the Cambrian through the Cretaceous (Figure 2). The only time period during this interval that is not represented is the Silurian.
    [Show full text]
  • Museum's Brochure Here
    Your Self Guided Tour To The Fossil Displays and More We hope this brochure makes it easier for LOOK CAREFULLY, at each dinosaur, you to see and enjoy all the exhibits provided but please, by the museum. Included is a map to assist in DO NOT TOUCH! locating all the exhibits and a brief description of what is on display. The dinosaurs are a Museum Hours: major focus of the museum’s exhibits. Everyday 9:00 a.m. - 10:00 p.m. Summer Hours (May-August) Please find the Map on the back 7:00 a.m. - 9:30 p.m. Tours available. cover to locate various displays. For further information about Western or the Natural History Museum please call 307-382-1600 Cenozoic Era Paleozoic Present to 66 million years ago 245 to 570 million years ago Yellowstone has had 3 major Sea deposits phosphates in explosive eruptions. west, red sand deposits in the east. Global extinction of 2 mill. yrs. Uplift of the western U.S. many marine invertebrates. Buffalo, Bull Lake, Pinedale glaciations. 286 mill. yrs. Wind blown sand forms the Mammals dominate the land. Tensleep, Weber, Casper, Minnelusa formations 24 mill. yrs. Sediments from the Miocene (all oil and gas producers). and Pliocene (2 to 24 mill. yrs.) is preserved in central 360 mill. yrs. Shallow sea covers the entire Wyoming Sweetwater Hills state forming the fossil rich area. End of the Laramide Madison Limestone. mountain building episode. 408 mill. yrs. Uplift in southwest 37 mill. yrs. Time of major deposites of Wyoming, diamond bearing coal, oil shale, and trona.
    [Show full text]
  • Incised Valley-Fill System Development and Stratigraphic
    INCISED VALLEY-FILL SYSTEM DEVELOPMENT AND STRATIGRAPHIC ANALYSIS OF THE LOWER CRETACEOUS KOOTENAI FORMATION, NORTHWEST MONTANA by Casey Ryan Reid A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Earth Sciences MONTANA STATE UNIVERSITY Bozeman, Montana April 2015 ©COPYRIGHT by Casey Ryan Reid 2015 All Rights Reserved ii ACKNOWLEDGEMENTS I would like to thank the Big Sky Carbon Sequestration Partnership and Vecta Oil and Gas for the financial and technical support received during this project. I would also like to thank my committee Dr. Jim Schmitt, Dr. Dave Bowen and Dr. Dave Lageson for their support and guidance throughout the duration of this thesis. Montana State University and the American Association of Petroleum Geologists are also acknowledged for financial support received and continued excellence in the geosciences. Without the support of my family and friends this project would surely never have been completed. While I am indebted to numerous people a number of specific words of thanks are necessary: to my parents whose love, guidance, and unwavering encouragement has never yielded, to my sisters who always supplied a welcome break from work and to my fellow geoscientists Jack Borksi, Nick Atwood, Nate Corbin, Ryan Hillier, and Colter Anderson. iii TABLE OF CONTENTS 1. INTRODUCTION, OBJECTIVES, & SIGNIFICANCE OF STUDY ...........................1 Introduction ......................................................................................................................1
    [Show full text]
  • Evolution of the Cordilleran Foreland Basin System in Northwestern Montana, U.S.A
    Evolution of the Cordilleran foreland basin system in northwestern Montana, U.S.A. Facundo Fuentes†, Peter G. DeCelles, Kurt N. Constenius, and George E. Gehrels Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA ABSTRACT episode of marine inundation and black shale 1989; Fermor and Moffat, 1992; Stockmal et al., deposition (Marias River Shale) occurred be- 1992; Beaumont et al., 1993; Plint et al., 1993; New lithostratigraphic and chronostrati- tween the Cenomanian and mid-Santonian, Ross et al., 2005; Miall et al., 2008; Yang and graphic, geochronologic, and sedimentary and was followed by a regressive succession Miall, 2009). This bimodal focus was mainly petrologic data illuminate the history of represented by the Upper Santonian–mid- driven by either the presence of anomalously development of the North American Cor- Campanian Telegraph Creek, Virgelle, and good surface exposures, as in the case of the dilleran foreland basin system and adjacent Two Medicine Formations. Provenance data western interior United States, or by hydro- thrust belt from Middle Jurassic through do not resolve the timing of individual thrust carbon exploration and a large subsurface data- Eocene time in northwestern Montana. The displacements during Cenomanian–early base, as in Canada (Miall et al., 2008). The oldest deposits in the foreland basin system Campanian time. The Upper Campanian ~300-km-long segment of the foreland basin consist of relatively thin, regionally tabu- Bearpaw Formation represents the last major lying within and east of the Cordilleran belt in lar deposits of the marine Ellis Group and marine inundation in the foreland basin . By northwestern Montana remains comparatively fl uvial-estuarine Morrison Formation, which latest Campanian time, a major epi sode of poorly understood in terms of its stratigraphy, accumulated during Bajocian to Kimmerid- slip on the Lewis thrust system had com- basin evolution, and relationship with the kine- gian time.
    [Show full text]
  • Triassic-Jurassic 'Red Beds' of the Rocky Mountain Region": a Discussion
    University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln USGS Staff -- Published Research US Geological Survey 1929 "Triassic-Jurassic 'Red Beds' of the Rocky Mountain Region": A Discussion John B. Reeside Jr. U.S. Geological Survey Follow this and additional works at: https://digitalcommons.unl.edu/usgsstaffpub Part of the Earth Sciences Commons Reeside, John B. Jr., ""Triassic-Jurassic 'Red Beds' of the Rocky Mountain Region": A Discussion" (1929). USGS Staff -- Published Research. 498. https://digitalcommons.unl.edu/usgsstaffpub/498 This Article is brought to you for free and open access by the US Geological Survey at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in USGS Staff -- Published Research by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. The Journal of Geology, Vol. 37, No. 1 (Jan. - Feb., 1929), pp. 47-63 "TRIASSIC-JURASSIC 'RED BEDS' OF THE ROCKY MOUNTAIN REGION": A DISCUSSION' JOHN B. REESIDE, JR. U.S. Geological Survey ABSTRACT The conclusion drawn by Professor E. B. Branson in a recent paper on the "Red Beds" of the Rocky Mountain region that parts of these beds are marine is considered likely. The conclusion that there exists no basis for subdivision of the beds is not accepted, and a division of the Mesozoic part into Lower Triassic, Upper Triassic, and Jurassic units is advocated. The conclusion that no eolian deposits are present likewise is not accepted, and the interpretation of important parts of the Jurassic unit as eolian is advocated. Disagreement is expressed with much of Professor Branson's correlation table, and a substitute is offered.
    [Show full text]