DOCSLIB.ORG

Lakamie Basin, Wyoming

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Lakamie Basin, Wyoming DEPARTMENT OF THE INTERIOR UNITED STATES GEOLOGICAL SURVEY GEORGE OTIS SMITH, DIRECTOR BULLETIN 364 GEOLOGY AND MINERAL RESOURCES OF THE LAKAMIE BASIN, WYOMING A PRELIMINARY REPORT BY N. H. DARTON AND C. E. SIEBENTHAL WASHINGTON GOVERNMENT PRINTING OFFICE 1909 CONTENTS. Page. Introduction............................................................. 7 Geography ............................................................... 8 Configuration........................................................ 8 Drainage ............................................................ 9 Climate ............................................................. 9 Temperature...................................................... 9 Precipitation..................................................... 10 Geology ................................................................. 11 Stratigraphy.......................................................... 11 General relations........................../....................... .11 Carboniferous system............................................. 13 Casper formation......................... .................... 13. General character........................................ 13 Thickness ............................................... 13 Local features............................................ 14 Erosion and weathering of limestone slopes ................ 18 Paleontology and age..................................... 19 Correlation .............................................. 20 Forelle limestone............................................. 20 Satanka shale................................................ 22 Triassic (?) system ............................................... 22 Chugwater formation......................................... 22 Character and distribution ................................ 22 Local features............................................ 23 Gypsiferous member ..................................... 25 Upper limestone ............i........... ................ 25 Age..................................................... 25 Jurassic system................................................... 26 Sundance formation .......................................... 26 Occurrence and relations.. -.._..................-......... 26 Fossils................................................... 27 Cretaceous system................................................ 27 Morrison formation........................................... 27 Distribution and general relations ........................'.. 27 Character................................................ 28 Fossils and age........................................... 29 Cloverly formation........................................... 30 Benton formation ............................................ 32 Distribution and general relations ......................... 32 Character................................................ 33 Fossils................................................... 34 Niobrara formation........................................... 34 Montana group............................................... 35 Distribution and general relations ......................... 35 Character................................................ 36 Fossils and age........................................... 37 3 4 CONTENTS. Geology Continued. Stratigraphy Continued. Page. Tertiary system.................................................. 43 Cooper Lake basin............................................ 43 Sheep Mountain Red Mountain region........................ 44 Little Medicine Bow Valley...................... ^............. 44 Quaternary system ............................................... 45 Glacial drift.................................................. 45 High terraces ................................................ 45 Alluvium.................................................... 46 Structure ............................................................ 46 Laramie mountain slopes.......................................... 46 Boulder Ridge anticline........................................... 47 Red Mountain Jelm Mountain area............................... 48 Centennial Valley................................................ 49 Sheep Mountain to Arlington.'..................................... 50 Rock River anticline........................................ ...... 51 Rock Creek anticline, .i........................... ................ 51 Coino anticline................................................... 52 Flattop anticline ................................................. 52 Freezeout uplift.................................................. 53 Mineral resources......................................................... 53 Coal................................................................. 53 Gypsum........................................ 1.................... 56 Rock gypsum ................................... 1................ 56 Gypsite ......................................................... 58 Bentonite... ... ...................................................... 58 Occurrence and character......................................... 58 Composition..................................................... 59 Use ............................................................. 60 Descriptions of localities.......................................... 60 Rock Creek region ........................................... 60 Chalk Bluffs................................................. 61 Hutton Lakes................................................ 61 Sand Creek.................................................. 61 Riverside.................................................... 61 Production and prices ............................................ 61 Sulphate of soda ...................................................... 61 Sulphate of magnesia................................................. 64 Volcanic ash......................................................... 65 Cement.............................................................. 65 Sand ................................................................ 65 Clay ................................................................ 66 Limestone........................................................... 66 Copper.............................................................. 66 Underground waters......................... ............................ 67 General conditions ................................................... 67 Description of wells .................................................. 68 Laramie......................................................... 68 Union Pacific Railroad............................................ 72 Pelton ranch..................................................... 73 Trabing ranch.................................................... 73 Downie ranch.................................................... 73 Alsop ranch....................................................... 73 CONTENTS. 5 Underground waters Continued. Description of wells Continued. Page. "Oilwell" ...................................................... 73 Mansfield ranch ......................^........................... 74 Homer ranch .......................... i.......................... 74 Button Creek .................................................... 74 Cooper Creek .................................................... 74 Arlington........................................................ 75 Springs............................................................... 75 Water analyses....................................................... 76 Index. .................................................................... 79 ILLUSTRATIONS. Page. PLATE I. Geological map of the Laramie Basin and adjacent portions of Albany County, Wyoming.................................... 7 II. A, Laramie Peak from the south; B, Cross-bedded sandstone of Casper formation on Sand Creek, Wyoming.................... 8 III. View across Laramie Plains looking southwest; Little Laramie River in the foreground....................................... 10 IV. Rock Creek valley near Rock River station...................... 12 V. A, Cross-bedded sandstone of Casper formation at Red Buttes, Wyoming; B, Pulpit Rock, south of Laramie, Wyoming........ 14 VI. Ay Sandstone in Montana group at Pine Ridge near Rock River station, Wyoming; J?, Sandstone in upper portion of Benton formation northwest of Medicine Bow, Wyoming............... 34 VII. A, Valley filled with Tertiary deposits at head of North Laramie River, summit of Laramie Mountains, Wyoming; li, Springs at fish hatchery south of Laramie, Wyoming...................... 44 VIII. Cross sections showing structure of the Laramie Basin, Wyoming.. 46 FIG. 1. Map of Wyoming, showing area treated in this report............... 7 U.S.GEOLOGICAL SURVEY GEORGE OTIS SMITH, DIRECTOR BULLETIN NO. 364 PL.I. GEOLOGIC MAP OF LARAMIE BASIX, WYOMING BY" X.H.DAHTOK AND C.E. SIEBENTHAL 5 o___________5 10 miles interval 25O feet. LEGEND TRIASSIC? PENNSYLVANIAN PRE- ' CRETACEOUS CRETACEOUS? JURASSIC PERMIAN MISSISSIPPIAN CAMBRIAN Gravels, sands.nnd. Aloutfma Montana. Uiobrara Benttm Gkn-eri^ Mairisoii Simdaaoe Chugwiiter Jasper Granite, dav;of several jJroup droup formation formation formation foiDialicm fopmatioTi tbrmation formation ^neiss.etc. formations f upper part) (lower part,) Satanka and. Mammad. -_-Fault. roreHemcltKkd : . 1908 GEOLOGY AND MINERAL RESOURCES OF LARAMIE BASIN, WYOMING: A PRELIMINARY REPORT. By N. H. DARTON and C. E. SIEBENTHAL. INTRODUCTION. The region
Load more

Recommended publications
  • The Black Hills Hydrology Study —By Janet M
    Prepared in cooperation with the South Dakota Department of Environment and Natural Resources and the West Dakota Water Development District The Black Hills Hydrology Study —By Janet M. Carter, Daniel G. Driscoll, and Joyce E. Williamson o Introduction 104o 45' 103 30' Indian Horse o Belle Fourche EXPLANATION 44 45' Reservoir Cr The Black Hills area is an impor- Owl Newell Outcrop of Madison Limestone BELLE Creek Creek tant resource center that provides an Nisland Outcrop of Minnelusa Formation F BELLE FOURCHE OU economic base for western South RCHE RIVER Approximate extent of the Black Hay Creek R E BUTTE CO Vale Hills area, represented by Dakota through tourism, agriculture, I V ER R MEADE CO REDWAT LAWRENCE CO generalized outer extent of the timber, and mineral resources. Water Cox the outcrop of Inyan Kara Saint Creek Lake Crow Onge Group originating from the area is used for Creek reek municipal, industrial, agricultural, and 30' Gulch Spearfish C Whitewood Bear x Gulch Butte Bottom Creek e recreational purposes throughout ls Bear a Creek F Whitewood Butte Higgins much of western South Dakota. The Cr Creek Squ STURGIS Spearfish a Central Tinton Cr w li Iron CityCr ka ood DEADWOOD l o Black Hills area also is an important Cr w A 103 ad 15' Beaver Cr e D Cr Lead Bear h nnie Cr s A berry recharge area for aquifers in the north- i traw f S r Cr Creek Tilford a hitetail e W p Cheyenne Elk S ern Great Plains. Crossing Little Creek Roubaix ek Creek N Elk re Elk Little C Population growth, resource devel- .
    [Show full text]
  • Taxonomic Overview of the Greater Fritillary Genus Speyeria Scudder
    INSECTA MUNDI A Journal of World Insect Systematics 0090 Taxonomic overview of the greater fritillary genus Speyeria Scudder and the atlantis hesperis species complexes, with species accounts, type images, and relevant literature (Lepidoptera: Nymphalidae) James C. Dunford McGuire Center for Lepidoptera and Biodiversity Florida Museum of Natural History, University of Florida PO Box 112710, Gainesville, FL 326112710, USA Date of Issue: September 26, 2009 CENTER FOR SYSTEMATIC ENTOMOLOGY, INC., Gainesville, FL James C. Dunford Taxonomic overview of the greater fritillary genus Speyeria Scudder and the atlantis hesperis species complexes, with species accounts, type images, and relevant literature (Lepidoptera: Nymphalidae) Insecta Mundi 0090: 174 Published in 2009 by Center for Systematic Entomology, Inc. P. O. Box 141874 Gainesville, FL 326141874 U. S. A. http://www.centerforsystematicentomology.org/ Insecta Mundi is a journal primarily devoted to insect systematics, but articles can be published on any nonmarine arthropod taxon. Manuscripts considered for publication include, but are not limited to, systematic or taxonomic studies, revisions, nomenclatural changes, faunal studies, book reviews, phylo genetic analyses, biological or behavioral studies, etc. Insecta Mundi is widely distributed, and refer- enced or abstracted by several sources including the Zoological Record, CAB Abstracts, etc. As of 2007, Insecta Mundi is published irregularly throughout the year, not as quarterly issues. As manuscripts are completed they are published and given an individual number. Manuscripts must be peer reviewed prior to submission, after which they are again reviewed by the editorial board to insure quality. One author of each submitted manuscript must be a current member of the Center for System- atic Entomology.
    [Show full text]
  • It's Unfair to the People of This Area for Us To
    “It’s unfair to the people of this area for us to collect taxes from our customers to help TVA [Tennessee Valley Authority] sell power at a lower price to their customers.” NEIL SIMPSON, President, Black Hills Power and Light Company 60 Expanding Futures on the Great Plains 4 EXPANDING FUTURES ON THE GREAT PLAINS Black Hills Power and Light continued to expand. The company absorbed smaller utilities. It offered power and transmission services to other areas in collaboration with public power agencies and rural electric cooperatives. But tensions with the rural cooperatives were building over territories and customers. As the federal government began to construct dams and hydroelectric facilities on the Missouri River, company officials scrambled to hold onto Black Hills Power and Light’s market and customers. 61 Expanding Futures on the Great Plains Govenor Peter Norbeck’s plan to build a dam dams on the river would revive the state’s proponents of the public power district bill were and hydroelectric facilities on the Missouri River economy. Their efforts to encourage the federal able to convince legislators that new districts after World War I died for lack of sufficient government to build a series of dams gained were needed to secure the power to be generated demand, but the idea lingered in the minds of momentum in 1943 after spring floods caused by Missouri River hydroelectric plants. The public many policymakers in Pierre and Washington, major damage to downstream communities, power district bill passed in 1950. D.C. After drought, depression and war, South especially Omaha, Nebraska.
    [Show full text]
  • Research Natural Areas on National Forest System Lands in Idaho, Montana, Nevada, Utah, and Western Wyoming: a Guidebook for Scientists, Managers, and Educators
    USDA United States Department of Agriculture Research Natural Areas on Forest Service National Forest System Lands Rocky Mountain Research Station in Idaho, Montana, Nevada, General Technical Report RMRS-CTR-69 Utah, and Western Wyoming: February 2001 A Guidebook for Scientists, Managers, and E'ducators Angela G. Evenden Melinda Moeur J. Stephen Shelly Shannon F. Kimball Charles A. Wellner Abstract Evenden, Angela G.; Moeur, Melinda; Shelly, J. Stephen; Kimball, Shannon F.; Wellner, Charles A. 2001. Research Natural Areas on National Forest System Lands in Idaho, Montana, Nevada, Utah, and Western Wyoming: A Guidebook for Scientists, Managers, and Educators. Gen. Tech. Rep. RMRS-GTR-69. Ogden, UT: U.S. Departmentof Agriculture, Forest Service, Rocky Mountain Research Station. 84 p. This guidebook is intended to familiarize land resource managers, scientists, educators, and others with Research Natural Areas (RNAs) managed by the USDA Forest Service in the Northern Rocky Mountains and lntermountain West. This guidebook facilitates broader recognitionand use of these valuable natural areas by describing the RNA network, past and current research and monitoring, management, and how to use RNAs. About The Authors Angela G. Evenden is biological inventory and monitoring project leader with the National Park Service -NorthernColorado Plateau Network in Moab, UT. She was formerly the Natural Areas Program Manager for the Rocky Mountain Research Station, Northern Region and lntermountain Region of the USDA Forest Service. Melinda Moeur is Research Forester with the USDA Forest Service, Rocky Mountain ResearchStation in Moscow, ID, and one of four Research Natural Areas Coordinators from the Rocky Mountain Research Station. J. Stephen Shelly is Regional Botanist and Research Natural Areas Coordinator with the USDA Forest Service, Northern Region Headquarters Office in Missoula, MT.
    [Show full text]
  • Black Hills Corporation Announces Acquisition of Cheyenne Light, Fuel & Power and Approval of Holding Company Application
    NEWS RELEASE Black Hills Corporation Announces Acquisition of Cheyenne Light, Fuel & Power and Approval of Holding Company Application 1/21/2005 RAPID CITY, S.D., Jan. 21 /PRNewswire-FirstCall/ -- Black Hills Corporation (NYSE: BKH) today announced the completion of its acquisition and the assumption of operational responsibility of Cheyenne Light, Fuel & Power Company (CLF&P). Black Hills Corporation purchased all the common stock of CLF&P, including the assumption of outstanding debt of approximately $25 million, for approximately $90 million, plus a working capital adjustment to be nalized in the second quarter of 2005. CLF&P was purchased from Xcel Energy Inc. (NYSE: XEL). Cheyenne Light, Fuel & Power serves approximately 38,000 electric and 31,000 natural gas customers in Cheyenne and other parts of Laramie County Wyoming. Its electric system peak load is 163 megawatts (MW), and power is supplied to the utility under an all-requirements contract with Public Service Company of Colorado, a subsidiary of Xcel Energy. The all-requirements contract expires in 2007. Annual gas distribution and transportation is approximately 5,000,000 MMBtu (million British thermal units). David R. Emery, President and Chief Executive Ocer of Black Hills Corporation, said, "We welcome this opportunity to serve our new customers in and around Cheyenne and to deliver reliable, value-priced energy. This acquisition increases the scope of our Wyoming-based energy endeavors, which includes power generation, wholesale and retail power delivery, coal mining and oil and natural gas production. We are very pleased with this acquisition and believe it increases our potential to expand our regional presence in the future." REGISTERED HOLDING COMPANY APPLICATION APPROVED The Company also announced that its application for nancing and investment authority in connection with its registration as a holding company under the Public Utilities Holding Company Act of 1935 was recently approved by the U.S.
    [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]
  • 5-Year Review Short Form Summary
    5-Year Review Short Form Summary Species Reviewed: Preble’s meadow jumping mouse (Zapus hudsonius preblei) FR Notice Announcing Initiation of This Review: March 31, 2004. 90-Day Finding for a Petition to Delist the Preble’s Meadow Jumping Mouse in Colorado and Wyoming and Initiation of a 5-Year Review (69 FR 16944-16946). Lead Region/Field Office: Region 6, Seth Willey, Recovery Coordinator, 303-236-4257. Colorado Field Office, Susan Linner, Field Supervisor, 303-236-4773. Name of Reviewer: Peter Plage, Colorado Field Office, 303-236-4750. Cooperating Field Office: Wyoming Field Office, Brian Kelly, Field Supervisor, 307-772-2374. Current Classification: Threatened rangewide. Current Recovery Priority Number: 9c. This recovery priority number is indicative of a subspecies facing a moderate degree of threat, a high recovery potential, and whose recovery may be in conflict with construction or other development projects or other forms of economic activity. Methodology used to complete the review: The 5-year review for the Preble’s meadow jumping mouse (Preble’s) was accomplished through the petition and rulemaking process. On December 23, 2003, we received two nearly identical petitions from the State of Wyoming’s Office of the Governor and from Coloradans for Water Conservation and Development, seeking to remove the Preble’s from the Federal List of Endangered and Threatened Wildlife. Both petitions were similar and maintained that the Preble’s should be delisted based on the taxonomic revision, and based on new distribution, abundance, and trends data that suggested the Preble’s was no longer threatened. On March 31, 2004, we published a notice announcing a 90-day finding that the petitions presented substantial information indicating that the petitioned action may be warranted and initiated a 5-year review (69 FR 16944-16946).
    [Show full text]
  • Denudation History and Internal Structure of the Front Range and Wet Mountains, Colorado, Based on Apatite-Fission-Track Thermoc
    NEW MEXICO BUREAU OF GEOLOGY & MINERAL RESOURCES, BULLETIN 160, 2004 41 Denudation history and internal structure of the Front Range and Wet Mountains, Colorado, based on apatite­fission­track thermochronology 1 2 1Department of Earth and Environmental Science, New Mexico Institute of Mining and Technology, Socorro, NM 87801Shari A. Kelley and Charles E. Chapin 2New Mexico Bureau of Geology and Mineral Resources, New Mexico Institute of Mining and Technology, Socorro, NM 87801 Abstract An apatite fission­track (AFT) partial annealing zone (PAZ) that developed during Late Cretaceous time provides a structural datum for addressing questions concerning the timing and magnitude of denudation, as well as the structural style of Laramide deformation, in the Front Range and Wet Mountains of Colorado. AFT cooling ages are also used to estimate the magnitude and sense of dis­ placement across faults and to differentiate between exhumation and fault­generated topography. AFT ages at low elevationX along the eastern margin of the southern Front Range between Golden and Colorado Springs are from 100 to 270 Ma, and the mean track lengths are short (10–12.5 µm). Old AFT ages (> 100 Ma) are also found along the western margin of the Front Range along the Elkhorn thrust fault. In contrast AFT ages of 45–75 Ma and relatively long mean track lengths (12.5–14 µm) are common in the interior of the range. The AFT ages generally decrease across northwest­trending faults toward the center of the range. The base of a fossil PAZ, which separates AFT cooling ages of 45– 70 Ma at low elevations from AFT ages > 100 Ma at higher elevations, is exposed on the south side of Pikes Peak, on Mt.
    [Show full text]
  • Published Proceedings from the CWD Forum
    PROCEEDINGS Jackson Hole Chronic Wasting Disease Forum December 7, 2016 National Museum of Wildlife Art Jackson, Wyoming INTRODUCTION The purpose of this Chronic Wasting Disease forum was to highlight CWD research and management considerations, with the goal to share current science-based information with the general public and all organizations concerned with the long-term health of elk and deer populations in the Jackson Hole Area. ABSTRACTS *Names of presenters in bold text Wyoming Chronic Wasting Disease Surveillance Mary Wood, State Veterinarian, Wildlife Veterinary Research Services, Wyoming Game and Fish Department, Laramie, Wyoming, USA Chronic Wasting Disease (CWD) was first described in captive mule deer from Colorado and Wyoming in the 1970’s (Williams 1980). After the initial discovery and description of this disease, the Wyoming Game and Fish Department (WGFD) began collaborative work with Dr. Elizabeth Williams in 1982 to investigate whether the disease was present in free-ranging populations (Williams 1992, Miller 2000). This was the beginning of a decades-long surveillance program to study the distribution and spread of this disease in free-ranging cervid populations. Between 1982 and 1997 a limited number of CWD samples were collected through local check stations near Laramie and Wheatland WY. WGFD surveillance began in earnest in 1997, with peak surveillance occurring between 2003 and 2011 when federal funding was available. Currently the WGFD Wildlife Health Laboratory tests between 1500 and 3500 samples for CWD each year with over 56,000 samples tested to date in Wyoming. Surveillance includes voluntary sample collection from hunter harvested animals as well as collection from road-killed animals and targeted animals showing signs consistent with CWD.
    [Show full text]
  • Grand Teton National Park Youngest Range in the Rockies
    GRAND TETON NATIONAL PARK YOUNGEST RANGE IN THE ROCKIES the town of Moran. Others recognized that dudes winter better than cows and began operating dude ranches. The JY and the Bar BC were established in 1908 and 1912, respectively. By the 1920s, dude ranch- ing made significant contributions to the valley’s economy. At this time some local residents real- ized that scenery and wildlife (especially elk) were valuable resources to be conserved rather than exploited. Evolution of a Dream The birth of present-day Grand Teton National Park involved controversy and a struggle that lasted several decades. Animosity toward expanding governmental control and a perceived loss of individual freedoms fueled anti-park senti- ments in Jackson Hole that nearly derailed estab- lishment of the park. By contrast, Yellowstone National Park benefited from an expedient and near universal agreement for its creation in 1872. The world's first national park took only two years from idea to reality; however Grand Teton National Park evolved through a burdensome process requiring three separate governmental Mt. Moran. National Park Service Photo. acts and a series of compromises: The original Grand Teton National Park, set Towering more than a mile above the valley of dazzled fur traders. Although evidence is incon- aside by an act of Congress in 1929, included Jackson Hole, the Grand Teton rises to 13,770 clusive, John Colter probably explored the area in only the Teton Range and six glacial lakes at the feet. Twelve Teton peaks reach above 12,000 feet 1808. By the 1820s, mountain men followed base of the mountains.
    [Show full text]
  • Late Pleistocene Glacial Equilibrium-Line Altitudes in the Colorado Front Range: a Comparison of Methods
    QUATERNARY RESEARCH l&289-310 (1982) Late Pleistocene Glacial Equilibrium-Line Altitudes in the Colorado Front Range: A Comparison of Methods THOMAS C. MEIERDING Department of Geography and Center For Climatic Research, University of Delaware, Newark, Delaware 19711 Received July 6, 1982 Six methods for approximating late Pleistocene (Pinedale) equilibrium-line altitudes (ELAs) are compared for rapidity of data collection and error (RMSE) from first-order trend surfaces, using the Colorado Front Range. Trend surfaces computed from rapidly applied techniques, such as glacia- tion threshold, median altitude of small reconstructed glaciers, and altitude of lowest cirque floors have relatively high RMSEs @I- 186 m) because they are subjectively derived and are based on small glaciers sensitive to microclimatic variability. Surfaces computed for accumulation-area ratios (AARs) and toe-to-headwall altitude ratios (THARs) of large reconstructed glaciers show that an AAR of 0.65 and a THAR of 0.40 have the lowest RMSEs (about 80 m) and provide the same mean ELA estimate (about 3160 m) as that of the more subjectively derived maximum altitudes of Pinedale lateral moraines (RMSE = 149 m). Second-order trend surfaces demonstrate low ELAs in the latitudinal center of the Front Range, perhaps due to higher winter accumulation there. The mountains do not presently reach the ELA for large glaciers, and small Front Range cirque glaciers are not comparable to small glaciers existing during Pinedale time. Therefore, Pleistocene ELA depression and consequent temperature depression cannot reliably be ascertained from the calcu- lated ELA surfaces. INTRODUCTION existed in alpine regions (Charlesworth, Glacial equilibrium-line altitudes (ELAs) 1957; ostrem, 1966; Flint, 1971; Andrews, have been widely used to infer present and 1975).
    [Show full text]
  • The Geology of New Mexico As Understood in 1912: an Essay for the Centennial of New Mexico Statehood Part 2 Barry S
    Celebrating New Mexico's Centennial The geology of New Mexico as understood in 1912: an essay for the centennial of New Mexico statehood Part 2 Barry S. Kues, Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, New Mexico, [email protected] Introduction he first part of this contribution, presented in the February Here I first discuss contemporary ideas on two fundamental areas 2012 issue of New Mexico Geology, laid the groundwork for an of geologic thought—the accurate dating of rocks and the move- exploration of what geologists knew or surmised about the ment of continents through time—that were at the beginning of Tgeology of New Mexico as the territory transitioned into statehood paradigm shifts around 1912. Then I explore research trends and in 1912. Part 1 included an overview of the demographic, economic, the developing state of knowledge in stratigraphy and paleontol- social, cultural, and technological attributes of New Mexico and its ogy, two disciplines of geology that were essential in understand- people a century ago, and a discussion of important individuals, ing New Mexico’s rock record (some 84% of New Mexico’s surface institutions, and areas and methods of research—the geologic envi- area is covered by sediments or sedimentary rocks) and which were ronment, so to speak—that existed in the new state at that time. advancing rapidly through the first decade of the 20th century. The geologic time scale and age of rocks The geologic time scale familiar to geologists working in New The USGS did not adopt the Paleocene as the earliest epoch of the Mexico in 1912 was not greatly different from that used by modern Cenozoic until 1939.
    [Show full text]