DOCSLIB.ORG

Explanation for Plates 2

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Explanation for Plates 2 DIGITAL DATA SERIES U.S. DEPARTMENT OF THE INTERIOR DDS-57 U.S. GEOLOGICAL SURVEY PLATE 1 EXPLANATION FOR PLATES 2 - 5 A A' 2 Arbitrary well number, keyed to index map (below) WEST Hell Creek 5 EAST 1 Formation 2501521037 American Petroleum Institute (API) well number (API number is composed of several Fox Hills 9 Volcanic rocks 8 Montana Power Company Operator name parts as shown here: 1 Sandstone Judith River Formation (incomplete) 8-8 Hettrick Well number and name 25 State code for Montana Bearpaw 12 Shale 10 11 Sec. 08,T. 29 N., R. 14 E. Spot location of well 015 County code for Chouteau Co. 3 4 KB 3,065 ft Elevation of kelly bushing (feet above sea level) 21037 Number for well within county) Judith River Formation 13 Judith River Formation Wildcat Field in which well is located olcanic rocks V Claggett Shale 14 TD 3,675 Total depth of well (feet above sea level) Eagle Sandstone and Telegraph Creek Formation Mississippian Madison Limestone Formation at total depth 7 Drilled and Abandoned Status of well Niobrara Formation 6 Carlile Shale 1 olcanic rocks Bowdoin sandstone DST: 1,035-1,095 (Eagle) Drill-stem test information: interval and formation tested, V Greenhorn Formation SI 30 min., open 1 hour 30 min., shut-in and open times, recovery, pressures. See below for Mosby Sandstone Member Phillips sandstone1 SI 1 hour 30 min; rec. 500 ft MCW; abbreviations used Belle Fourche Shale FP 70-285, SIP 358-358, HP 590-582 Mowry Shale Shell Creek Shale Stratigraphic notes: 1 Notes on stratigraphic units in the well. These consist Muddy Sandstone of operator's picks of some stratigraphic units and Skull Creek Shale Basal silt unit of 1. Operator's pick of Virgelle Sandstone observations from sample descriptions. Notes are Skull Creek Shale Fall River Sandstone Member of Eagle Sandstone at 1,161 ft keyed to numbers along the right margins of the logs Kootenai Formation 1 Jurassic rocks Of subsurface usage Meters Feet B' Producing interval 5000 B 1500 EAST WEST 25 26 Fort Union Drill stem test interval Formation 4000 Hell Creek 20 24 Formation Geophysical logs: 19 23 1000 Fox Hills Sandstone 21 Log traces were scanned from the best 22 available copies of public domain wells. 3000 Bearpaw Shale 18 Most logs are varieties of electrical logs, which have spontaneous potential, resistivity, and conductivity curves. Some wells have caliper and gamma-ray curves on the left and Judith River Formation density porosity and neutron porosity 2000 Abbreviations 15 Claggett Shale on the right. 16 17 SI Shut-in 500 1500 Gammon Shale FP Flow pressure SIP Shut-in pressure All pressures are FSIP Final shut-in pressure reported in pounds Niobrara Formation HP Hydrostatic pressure 300 1000 Perfs. Perforated intervals Carlile Shale 1 MCFGPD Thousand cubic feet of gas per day 200 Bowdoin sandstone Greenhorn Formation 1 MCW Mud cut water 500 Phillips sandstone Belle Fourche Shale Mosby Sandstone Member GCM Gas cut mud 400 100 300 Mowry Shale GCW Gas cut water 50 200 SGCM Slightly gas cut mud 100 Shell Creek Shale 0 0 SGCMW Slightly gas cut muddy water Muddy Sandstone SMCW Slightly mud cut water Skull Creek Shale SWTR Salt water Basal silt unit of Skull Creek Shale Fall River Sandstone VSGCM Very slightly gas cut mud Kootenai Formation SWCM Salt water cut mud vertical scale: 1 inch = 800 ft 1Of subsurface usage WCM Water cut mud horizontal scale: 1 inch = 10 miles Jurassic rocks KB Kelly bushing vertical exaggeration = x66 GR Ground elevation TD Total depth DST Drill stem test GTS Gas to surface C C' 0 5 10 MILES SOUTH NORTH 28 29 0 5 10 KILOMETERS Fort Union Formation Hell Creek 35 and Formation 38 Hell Creek Formation 30 32 Hell Creek Formation (incomplete) 27 33 Fox Hills Sandstone Fox Hills Sandstone 36 Bearpaw Shale 34 31 37 Judith River Formation Claggett Shale 110o 109o 108o 107o 106o 105o 104o Gammon Shale 57 58 54 55 56 51 52 53 Saskatchewan 48 49 50 44 45 46 47 Niobrara Formation 41 42 43 37 38 39 40 32 33 34 35 36 CANADA 28 29 30 31 Montana o 21 22 23 24 25 26 27 37 Carlile Shale 49 111E 12 13 14 15 16 17 18 19 20 Bowdoin dome Greenhorn Formation UNITED STATES 36 Mosby Sandstone Member 35 Belle Fourche Shale D' 34 49 Mowry Shale Milk River 33 Fort Peck Indian Reservation Shell Creek Shale Basal silt unit of Skull Creek Shale Harlem 32 Muddy Sandstone 2 13 14 A' Saco B' Havre Skull Creek Shale 12 31 20 B 21 15 16 19 25 26 Fall River Sandstone 48 30 17 Kootenai Formation Malta 18 22 24 Culbertson 6 7 9 10 11 47 23 3 5 46 29 Jurassic rocks 8 A 1 2 Fort Belknap Glasgow Wolf Point Missouri River 4 Bears Paw Mountains Indian 191 45 28 Reservation 2 Rocky Boys 44 27 87 Fort Peck Indian Reservation Little 26 Rocky o Mountains 48 25 Sidney 66 24 43 D Missouri River 23 FORT PECK LAKE D' 22 SOUTH 39 NORTH 21 42 e Circle in Hell Creek l 38 Formation 41 20 41 re 40 o Fox Hills Sandstone 19 h Suffolk 40 Jordan S 42 e nd lin 18 39 ta ore Axis of tr D 38 s h 17 ow Glendive S s L 43 d C' ou n 16 ce Bearpaw Shale ta ta I-94 s ansg 37 re w 15 C o and Mo 36 y 44 45 L ression of Skull Creek rl 14 35 a o s Mosby E 46 47 u Judith River Formation o wr 13 e y sea 34 c Claggett Shale a 12 t 32 33 e r w 11 48 14 49 a 31 C ys Gammon Shale y 10 30 47 l I-94 r a 87 9 29 Niobrara Formation E ellowstone River 8 Y Musselshell River Carlile Shale 1 28 7 Greenhorn Formation Bowdoin sandstone Mosby Sandstone Member Phillips sandstone1 6 StudyArea Belle Fourche Shale Bull Mountains 5 Mowry Shale 4 Shell Creek Shale Muddy Sandstone 27 3 Skull Creek Shale o Dry hole 46 C 2 Gas-producing well Basal silt unit of Skull Creek Shale I-94 Oil-producing well Fall River Sandstone 1N Unclassified well Kootenai Formation Billings 1Of subsurface usage Jurassic rocks Base modified from U.S. Geological Survey 1:2,000,000-scale 10 0 10 20 30 40 50 MILES digital line graph data (1980), which was digitized from the 1970 National Atlas of the United States. Township grid modifed from Montana State Library data (1996). 20 0 20 40 60 80 100 KILOMETERS Universal Transverse Mercator projection, zone 13 Restored stratigraphic diagrams of cross sections A-A', B-B', C-C', and D-D'. Map showing the locations of cross sections in northeastern Montana. Axis of transgression of Skull Creek and Mowry seaways from Dolson and others (1991), lowstand shorelines from Porter and others (1998). STRATIGRAPHIC FRAMEWORK OF LOWER AND UPPER CRETACEOUS ROCKS IN CENTRAL AND EASTERN MONTANA By Steven M. Condon 2000.
Load more

Recommended publications
  • Post-Carboniferous Stratigraphy, Northeastern Alaska by R
    Post-Carboniferous Stratigraphy, Northeastern Alaska By R. L. DETTERMAN, H. N. REISER, W. P. BROSGE,and]. T. DUTRO,JR. GEOLOGICAL SURVEY PROFESSIONAL PAPER 886 Sedirnentary rocks of Permian to Quaternary age are named, described, and correlated with standard stratigraphic sequences UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON 1975 UNITED STATES DEPARTMENT OF THE INTERIOR ROGERS C. B. MORTON, Secretary GEOLOGICAL SURVEY V. E. McKelvey, Director Library of Congress Cataloging in Publication Data Detterman, Robert L. Post-Carboniferous stratigraphy, northeastern Alaska. (Geological Survey Professional Paper 886) Bibliography: p. 45-46. Supt. of Docs. No.: I 19.16:886 1. Geology-Alaska. I. Detterman, Robert L. II. Series: United States. Geological Survey. Professional Paper 886. QE84.N74P67 551.7'6'09798 74-28084 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 Stock Number 024-001-02687-2 CONTENTS Page Page Abstract __ _ _ _ _ __ __ _ _ _ _ _ _ _ _ _ _ _ _ __ __ _ _ _ _ _ _ __ __ _ _ __ __ __ _ _ _ _ __ 1 Stratigraphy__:_Continued Introduction __________ ----------____ ----------------____ __ 1 Kingak Shale ---------------------------------------- 18 Purpose and scope ----------------------~------------- 1 Ignek Formation (abandoned) -------------------------- 20 Geographic setting ------------------------------------ 1 Okpikruak Formation (geographically restricted) ________ 21 Previous work and acknowledgments ------------------ 1 Kongakut Formation ----------------------------------
    [Show full text]
  • Understanding and Mapping Variability of the Niobrara Formation
    UNDERSTANDING AND MAPPING VARIABILITY OF THE NIOBRARA FORMATION ACROSS WATTENBERG FIELD, DENVER BASIN by Nicholas Matthies A thesis submitted to the Faculty and the Board of Trustees of the Colorado School of Mines in partial fulfillment of the requirements for the degree of Master of Science (Geology). Golden, Colorado Date________________ Signed:____________________________________ Nicholas Matthies Signed:____________________________________ Dr. Stephen A. Sonnenberg Thesis Advisor Golden, Colorado Date:_______________ Signed:____________________________________ Dr. Paul Santi Professor and Head Department of Geology and Geological Engineering ii ABSTRACT Wattenberg Field has been a prolific producer of oil and gas since the 1970s, and a resurgence of activity in recent years in the Niobrara Formation has created the need for a detailed study of this area. This study focuses on mapping regional trends in stratigraphy, structure, and well log properties using digital well logs, 3D seismic data, and core X-ray diffraction data. Across Wattenberg, the Niobrara is divided into the Smoky Hill Member (made up of A Chalk, A Marl, B Chalk, B Marl, C Chalk, C Marl, and Basal Chalk/Marl) and the Fort Hays Limestone Member. Directly beneath the Niobrara, the Codell Sandstone is the uppermost part of the Carlile Formation. Stratigraphic trends in these units are primarily due to differential compaction and compensational sedimentation. The largest structural trend is a paleo-high that runs east-west to northeast-southwest across the middle of the field. It has a relief of about 100 ft, and is 20 mi wide. The A Chalk and A Marl show evidence of submarine erosion over this area. Faults mapped from 3D seismic data are consistent with previously published data on a proposed polygonal fault system in the Denver Basin.
    [Show full text]
  • Hydrogeology and Stratigraphy of the Dakota Formation in Northwest Iowa
    WATER SUPPLY HYDROGEOLOGY AND J.A. MUNTER BULLETIN G.A. LUDVIGSON NUMBER 13 STRATIGRAPHY OF THE B.J. BUNKER 1983 DAKOTA FORMATION IN NORTHWEST IOWA Iowa Geological Survey Donald L. Koch State Geologist and Director 123 North Capitol Street Iowa City, Iowa 52242 IOWA GEOLOGICAL SURVEY WATER-SUPPLY BULLETIN NO. 13 1983 HYDROGEOLOGY AND STRATIGRAPHY OF THE DAKOTA FORMATION IN NORTHWEST IOWA J. A. Munter G. A. Ludvigson B. J. Bunker Iowa Geological Survey Iowa Geological Survey Donald L. Koch Director and State Geologist 123 North Capitol Street Iowa City, Iowa 52242 Foreword An assessment of the quantity and quality of water available from the Dakota (Sandstone) Formation 1n northwest Iowa is presented in this report. The as sessment was undertaken to provide quantitative information on the hydrology of the Dakota aquifer system to the Iowa Natural Resources Council for alloca tion of water for irrigation, largely as a consequence of the 1976-77 drought. Most area wells for domestic, livestock, and irrigation purposes only partial ly penetrated the Dakota Formation. Consequently, the long-term effects of significant increases in water withdrawals could not be assessed on the basis of existing wells. Acquisition of new data was based upon a drilling program designed to penetrate the entire sequence of Dakota sediments at key loca tions, after a thorough inventory and analysis of existing data. Definition of the distribution, thickness, and lateral and vertical changes in composition of the Dakota Formation has permitted the recognition of two mem bers. Additionally, Identification of the rock units that underlie the Dakota Formation has contributed greatly to our knowledge of the regional geology of northwest Iowa and the upper midwest.
    [Show full text]
  • Stratigraphy of the Upper Cretaceous Fox Hills Sandstone and Adjacent
    Stratigraphy of the Upper Cretaceous Fox Hills Sandstone and AdJa(-erit Parts of the Lewis Sliale and Lance Formation, East Flank of the Rock Springs Uplift, Southwest lo U.S. OEOLOGI AL SURVEY PROFESSIONAL PAPER 1532 Stratigraphy of the Upper Cretaceous Fox Hills Sandstone and Adjacent Parts of the Lewis Shale and Lance Formation, East Flank of the Rock Springs Uplift, Southwest Wyoming By HENRYW. ROEHLER U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 1532 Description of three of/lapping barrier shorelines along the western margins of the interior seaway of North America UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1993 U.S. DEPARTMENT OF THE INTERIOR BRUCE BABBITT, Secretary U.S. GEOLOGICAL SURVEY Dallas L. Peck, Director Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government. Library of Congress Cataloging-in-Publication Data Roehler, Henry W. Stratigraphy of the Upper Cretaceous Fox Hills sandstone and adjacent parts of the Lewis shale and Lance formation, east flank of the Rock Springs Uplift, southwest Wyoming / by Henry W. Roehler. p. cm. (U.S. Geological Survey professional paper ; 1532) Includes bibliographical references. Supt.ofDocs.no.: I19.16:P1532 1. Geology, Stratigraphic Cretaceous. 2. Geology Wyoming. 3. Fox Hills Formation. I. Geological Survey (U.S.). II. Title. III. Series. QE688.R64 1993 551.7T09787 dc20 92-36645 CIP For sale by USGS Map Distribution Box 25286, Building 810 Denver Federal Center Denver, CO 80225 CONTENTS Page Page Abstract......................................................................................... 1 Stratigraphy Continued Introduction................................................................................... 1 Formations exposed on the east flank of the Rock Springs Description and accessibility of the study area ................
    [Show full text]
  • Niobrara Total Petroleum System in the Southwestern Wyoming Province
    Chapter 6 Niobrara Total Petroleum System in the Southwestern Wyoming Province By Thomas M. Finn and Ronald C. Johnson Volume Title Page Chapter 6 of Petroleum Systems and Geologic Assessment of Oil and Gas in the Southwestern Wyoming Province, Wyoming, Colorado, and Utah By USGS Southwestern Wyoming Province Assessment Team U.S. Geological Survey Digital Data Series DDS–69–D U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior Gale A. Norton, Secretary U.S. Geological Survey Charles G. Groat, Director U.S. Geological Survey, Denver, Colorado: Version 1, 2005 For sale by U.S. Geological Survey, Information Services Box 25286, Denver Federal Center Denver, CO 80225 For product and ordering information: World Wide Web: http://www.usgs.gov/pubprod Telephone: 1-888-ASK-USGS For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment: World Wide Web: http://www.usgs.gov Telephone: 1-888-ASK-USGS Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this report. Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government. Manuscript approved for publication May 10, 2005 ISBN= 0-607-99027-9 Contents Abstract ……………………………………………………………………………………… 1 Introduction …………………………………………………………………………………… 1 Acknowledgments ……………………………………………………………………………
    [Show full text]
  • North-Central Montana
    Petrology of the Eagle Sandstone, Bearpaw Mountains Area, North-Central Montana By DONALD L. GAUTIER INVESTIGATIONS OF SHALLOW GAS RESERVOIRS IN THE NORTHERN GREAT PLAINS GEOLOGICAL SURVEY BULLETIN 1521 Prepared in cooperation with the U. S. Depart1Tl£nt of Energy Composition and burial history of an important conventional shallow methane reservoir in the northern Great Plains UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1981 UNITED STATES DEPARTMENT OF THE INTERIOR JAMES G. WATT, Secretary GEOLOGICAL SURVEY Dallas L. Peck, Director Library of Congress Cataloging in Publication Data . Gautier, Donald L. Petrology of the Eagle Sandstone, Bearpaw Mountains area, north-central Montana. (Investigations of shallow gas reservoirs in the northern Great Plains) (Geological Survey Bulletin 1521) Bibliography: p. 52 1. Sandstone-Montana-Bearpaw Mountains region. 2. Gas, Natural-Geology­ Montana-Bearpaw Mountains region. I. Title. II. Series. III. Series: Geological Survey Bulletin 1521. QE75.B9 no. 1521 [QE471.15.S25] 557.3s 81-607963 [552'.5] AACR2 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 CONTENTS Page Absuact:---------------------------------------------------- 1 In~uction------------------------------------------------- 2 ~~un~--------------------------------------------- 4 Acknowledgments-------------------------------------- 5 Geologic Setting----------------------------------- 6 Hydrocarbons in the Eagle Sandstone------------------------ 8 Lithology----------------------------------------
    [Show full text]
  • FORT BELKNAP RESERVATION List of Topics
    FORT BELKNAP RESERVATION List of Topics BACKGROUND Reservation Overview Regional Geologic Overview GEOLOGIC OVERVIEW Geologic History Summary of Play Types CONVENTIONAL PLAY TYPES Play 1 - Shallow Cretaceous Biogenic Gas Play Play 2 - Northern Plains Biogenic Gas Play Plays 3,4,5 - Jurassic/Cretaceous and Mississippian Plays UNCONVENTIONAL / HYPOTHETICAL PLAY TYPES Plays 6,7 - Fractured Bakken and Cambrian Sandstone Plays REFERENCES Historical Background of the OVERVIEW (i.e. joint ventures) in contrast to procedures and regulatory minimums imposed Assiniboine and Gros Ventre Tribes at Fort Belknap by the previous 1938 Minerals Leasing Act. The 1982 Act further provides that FORT BELKNAP RESERVATION The Fort Belknap Indian Reservation was created in 1887 as the home for the individual Indian allottees may join agreements negotiated for tribal lands. The Assiniboine and Gros Ventre Tribes Assiniboine and Gros Ventre Indian Tribes. The ancestors of these tribes have section entitled Operating Regulations discusses the procedures for obtaining lived on the northern plains for several centuries. The Assiniboine were allottee participance in the negotiated agreement. recognized by Europeans as part of the great Sioux Nation and speak a Siouan Principal components for the formal corporate proposal should include the TRIBAL HEADQUARTERS: Fort Belknap Agency, Montana language. However, their name is taken from a Chippewa word referring to area(s) of interest, type of contract, elaboration of proposed agreement terms, GEOLOGIC SETTING: Williston Basin "those who cook with stones." At some point in time the Assiniboine bands points of potential negotiation, diligence commitments (i.e. drilling), bonus broke with the traditional Sioux and allied themselves with the Cree.
    [Show full text]
  • The Cretaceous System in Central Sierra County, New Mexico
    The Cretaceous System in central Sierra County, New Mexico Spencer G. Lucas, New Mexico Museum of Natural History, Albuquerque, NM 87104, [email protected] W. John Nelson, Illinois State Geological Survey, Champaign, IL 61820, [email protected] Karl Krainer, Institute of Geology, Innsbruck University, Innsbruck, A-6020 Austria, [email protected] Scott D. Elrick, Illinois State Geological Survey, Champaign, IL 61820, [email protected] Abstract (part of the Dakota Formation, Campana (Fig. 1). This is the most extensive outcrop Member of the Tres Hermanos Formation, area of Cretaceous rocks in southern New Upper Cretaceous sedimentary rocks are Flying Eagle Canyon Formation, Ash Canyon Mexico, and the exposed Cretaceous sec- Formation, and the entire McRae Group). A exposed in central Sierra County, southern tion is very thick, at about 2.5 km. First comprehensive understanding of the Cretaceous New Mexico, in the Fra Cristobal Mountains, recognized in 1860, these Cretaceous Caballo Mountains and in the topographically strata in Sierra County allows a more detailed inter- pretation of local geologic events in the context strata have been the subject of diverse, but low Cutter sag between the two ranges. The ~2.5 generally restricted, studies for more than km thick Cretaceous section is assigned to the of broad, transgressive-regressive (T-R) cycles of 150 years. (ascending order) Dakota Formation (locally deposition in the Western Interior Seaway, and includes the Oak Canyon [?] and Paguate also in terms of Laramide orogenic
    [Show full text]
  • Schmitz, M. D. 2000. Appendix 2: Radioisotopic Ages Used In
    Appendix 2 Radioisotopic ages used in GTS2020 M.D. SCHMITZ 1285 1286 Appendix 2 GTS GTS Sample Locality Lat-Long Lithostratigraphy Age 6 2s 6 2s Age Type 2020 2012 (Ma) analytical total ID ID Period Epoch Age Quaternary À not compiled Neogene À not compiled Pliocene Miocene Paleogene Oligocene Chattian Pg36 biotite-rich layer; PAC- Pieve d’Accinelli section, 43 35040.41vN, Scaglia Cinerea Fm, 42.3 m above base of 26.57 0.02 0.04 206Pb/238U B2 northeastern Apennines, Italy 12 29034.16vE section Rupelian Pg35 Pg20 biotite-rich layer; MCA- Monte Cagnero section (Chattian 43 38047.81vN, Scaglia Cinerea Fm, 145.8 m above base 31.41 0.03 0.04 206Pb/238U 145.8, equivalent to GSSP), northeastern Apennines, Italy 12 28003.83vE of section MCA/84-3 Pg34 biotite-rich layer; MCA- Monte Cagnero section (Chattian 43 38047.81vN, Scaglia Cinerea Fm, 142.8 m above base 31.72 0.02 0.04 206Pb/238U 142.8 GSSP), northeastern Apennines, Italy 12 28003.83vE of section Eocene Priabonian Pg33 Pg19 biotite-rich layer; MASS- Massignano (Oligocene GSSP), near 43.5328 N, Scaglia Cinerea Fm, 14.7 m above base of 34.50 0.04 0.05 206Pb/238U 14.7, equivalent to Ancona, northeastern Apennines, 13.6011 E section MAS/86-14.7 Italy Pg32 biotite-rich layer; MASS- Massignano (Oligocene GSSP), near 43.5328 N, Scaglia Cinerea Fm, 12.9 m above base of 34.68 0.04 0.06 206Pb/238U 12.9 Ancona, northeastern Apennines, 13.6011 E section Italy Pg31 Pg18 biotite-rich layer; MASS- Massignano (Oligocene GSSP), near 43.5328 N, Scaglia Cinerea Fm, 12.7 m above base of 34.72 0.02 0.04 206Pb/238U
    [Show full text]
  • Unconventional Shallow Biogenic Gas Systems
    Unconventional shallow AUTHORS George W. Shurr ϳ GeoShurr Resources, biogenic gas systems LLC, Rt. 1, Box 91A, Ellsworth, Minnesota, 56129; [email protected] George W. Shurr and Jennie L. Ridgley George W. Shurr is an independent geologist and partner in GeoShurr Resources, LLC. He recently retired from a thirty-year career of university teaching and consulting. His B.A. ABSTRACT degree is from the University of South Dakota, Unconventional shallow biogenic gas falls into two distinct systems his M.S. degree is from Northwestern that have different attributes. Early-generation systems have blan- University, and his Ph.D. is from the University of Montana. His research interests include ketlike geometries, and gas generation begins soon after deposition shallow gas systems on basin margins, of reservoir and source rocks. Late-generation systems have ringlike lineament block tectonics, and Cretaceous geometries, and long time intervals separate deposition of reservoir stratigraphy in the northern Great Plains. and source rocks from gas generation. For both types of systems, the gas is dominantly methane and is associated with source rocks Jennie L. Ridgley ϳ U.S. Geological Survey, that are not thermally mature. Box 25046, MS 939, Denver, Colorado, Early-generation biogenic gas systems are typified by produc- 80225-0046; [email protected] tion from low-permeability Cretaceous rocks in the northern Great Jennie Ridgley received her B.S. degree in Plains of Alberta, Saskatchewan, and Montana. The main area of mathematics from Pennsylvania State production is on the southeastern margin of the Alberta basin and University and M.S. degree in geology from the northwestern margin of the Williston basin.
    [Show full text]
  • Mesozoic Stratigraphy at Durango, Colorado
    160 New Mexico Geological Society, 56th Field Conference Guidebook, Geology of the Chama Basin, 2005, p. 160-169. LUCAS AND HECKERT MESOZOIC STRATIGRAPHY AT DURANGO, COLORADO SPENCER G. LUCAS AND ANDREW B. HECKERT New Mexico Museum of Natural History and Science, 1801 Mountain Rd. NW, Albuquerque, NM 87104 ABSTRACT.—A nearly 3-km-thick section of Mesozoic sedimentary rocks is exposed at Durango, Colorado. This section con- sists of Upper Triassic, Middle-Upper Jurassic and Cretaceous strata that well record the geological history of southwestern Colorado during much of the Mesozoic. At Durango, Upper Triassic strata of the Chinle Group are ~ 300 m of red beds deposited in mostly fluvial paleoenvironments. Overlying Middle-Upper Jurassic strata of the San Rafael Group are ~ 300 m thick and consist of eolian sandstone, salina limestone and siltstone/sandstone deposited on an arid coastal plain. The Upper Jurassic Morrison Formation is ~ 187 m thick and consists of sandstone and mudstone deposited in fluvial environments. The only Lower Cretaceous strata at Durango are fluvial sandstone and conglomerate of the Burro Canyon Formation. Most of the overlying Upper Cretaceous section (Dakota, Mancos, Mesaverde, Lewis, Fruitland and Kirtland units) represents deposition in and along the western margin of the Western Interior seaway during Cenomanian-Campanian time. Volcaniclastic strata of the overlying McDermott Formation are the youngest Mesozoic strata at Durango. INTRODUCTION Durango, Colorado, sits in the Animas River Valley on the northern flank of the San Juan Basin and in the southern foothills of the San Juan and La Plata Mountains. Beginning at the northern end of the city, and extending to the southern end of town (from north of Animas City Mountain to just south of Smelter Moun- tain), the Animas River cuts in an essentially downdip direction through a homoclinal Mesozoic section of sedimentary rocks about 3 km thick (Figs.
    [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]