DOCSLIB.ORG

Structural and Igneous Geology of the La Sal Mountains, Utah by CHARLES B

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Structural and Igneous Geology of the La Sal Mountains, Utah By CHARLES B. HUNT SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY GEOLOGICAL SURVEY PROFESSIONAL PAPER 294-1 With collaboration by Aaron C. Waters on the North La Sal stock and the origin and evolution of the magmas UNITED STATES GOVERNMENT PRINTING OFFICE WASHINGTON : 1958 UNITED STATES DEPARTMENT OF THE INTERIOR FRED A. SEATON, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U. S. Government Printing Office Washington 25, D. C. CONTENTS Page Page Abstract__._______._.__._..___.__________ 305 Intrusions and intrusive structures—Continued Introduction _______________________________________ 305 Intrusions on North Mountain—Continued Previous investigations._________________________ 306 Diorite porphyry laccoliths and related intru­ Present investigation and acknowledgments______ 307 sions—Continued General setting of the mountains _________________ 307 Laccoliths southwest of the stock — _—__ 320 Stratigraphy--- ———— ____ — ____.__________ 309 Haystack Mountain laccolith____ — — _ 322 Concealed formations.__________________________ 311 Mill Creek sill_-_._-------_________ 322 Precambrian complex_______________________ 311 Laccoliths northwest of the stock_______ 322 Carboniferous systems____________________ 311 Laccoliths northeast of the stock.________ 323 Pennsylvanian system_____________________ 311 Intrusions between Willow Basin and Bear Paradox member of the Hermosa forma­ Creek......___________-... 323 tion—____________________ 311 Beaver Creek laccolith---.-.-...-------- 323 Hermosa and Rico formations_________ 312 Round Mountain bysmalith________-_-_. 323 Exposed formations_____-_______________________ 312 Monzonite porphyry sills and dikes_____-----_ 324 Pennsylvanian and Permian systems________ 312 Petrography. __--_-_---_--_----_---_-_- 324 Cutler formation_____________________ 312 Placer Creek sill_______ ______—— 324 Triassic system_______________________________ 312 Other dikes and sills.______________ — __ 324 Lower and Middle(?) Triassic series________ 312 North La Sal stock, by Charles B. Hunt and Moenkopi formation.___________________ 312 Aaron C. Waters..-..-_—_———————— 325 Upper Triassic series____________________ 312 General features.----.---------.--—____ 325 Shinarump conglomerate and Chinle for­ Diorite porphyry._____-__-._____.._.— 325 mation. _____________________________ 312 Monzonite porphyry______________-----_ 326 Triassic and Jurassic systems__._-___--________. 312 Dike-swarm complex___-_-______-__---_- 326 Glen Canyon group and Entrada sandstone_ _ 312 Feldspathoidal and other soda-rich dikes— 328 Jurassic system_______________________________ 313 Soda syenite porphyry——————— ———— 328 Explosion breccias and associated aegirine Upper Jurassic series__-___________._________ 313 Morrison formation.....________________ 313 granite porphyry and aphanitic sheets. __ 331 Soda rhyolite porphyry dikes.____-_-----_ 333 Cretaceous system______________________________ 313 Summary of the structural history of the Lower(?) and Upper Cretaceous series_______ 313 North La Sal stock...._______... 333 Dakota sandstone____________________ 313 Rock alteration on North Mountain_„___—__-_ 334 Upper Cretaceous series.____________________ 313 Structural control of altered zones. _--____ 334 Mancos shale._________________________ 313 Degree of alteration....-----.----------- 335 Tertiary(?) system____________________ 314 Alteration minerals.___--_-_-___-_------ 335 Pliocene(?) series_____-______ —__- — _______- 314 Distribution of metals____-------_------- 338 Conglomerate in Castle Valley_________ 314 Source of the alteration products______--_ 339 Quaternary system____________________________ 314 Pleistocene and Recent deposits ______________ 314 Middle Mountain_____ _ _________————— 339 Brumley Creek laccolith___-_________--_---_- 340 Structural geology____________-_____________________ 314 Dorry Canyon laccolith.——________-_-_-._-- 341 Structural features surrounding the mountains. ____ 314 Mount Tukuhnikivatz laccolith________.---- 341 Details of folds adjacent to the mountains..... 315 Intrusions at head of La Sal Creek_______--_ 341 Castle Creek anticline_____-____.________ 315 Mount Peale laccolith-__-_-_---____--------- 342 Moab anticline and the Spanish Valley-Pack Mount Mellenthin laccoliths.__________----.- 343 Creek synclines_______________________ 315 Blue Lake laccolith-..-.-_-.-_—————— 343 Area adjacent to Middle Mountain.______ 316 Intrusions in Horse Canyon._________________ 344 Other folds nearby,.______.____.__ 316 Brumley Ridge noselite syenite porphyry. _____ 344 Structure of the La Sal Mountains.______________ 316 Middle Mountain stock——_________ — ___-_ 344 Relation between the La Sal Mountains and the South Mountain—___-__________--_ — -.-_------- 345 regional structures.-..-.__________________ 318 Pack Creek laccolith. ________———— 345 Intrusions and intrusive structures__________________ 318 Laccolith southeast of the stock——— _________ 345 Intrusions on North Mountain..-..__...___ 318 Intrusions south and west of the stock——_____ 346 Diorite porphyry laccoliths and related intru­ Intrusions northeast of the stock—— __________ 346 sions. ___________________________________ 319 South Mountain stock____________ —— __— 346 Petrography.-.________________ 319 Summary comparison of the volumes and positions of Laccoliths southeast of the stock _________ 320 the intrusions______._____--_.__.__._.__-_---- 346 in IV CONTENTS Page Page Origin and evolution of the magmas, by Aaron C. Waters Economic geology—Continued and Charles B. Hunt____________________ 348 Placer deposits__________-__..____-_--______.____ 355 Inadequacy of crystallization differentiation of Metalliferous deposits in the intrusions-___________ 355 basalt_______________________ 348 Mine descriptions_-_-__-___-______-__-__________ 356 Evidence from inclusions...-_-___--______-_______ 349 Dillon adit.._.__.________________ 356 Palingenesis of amphibolite______________________ 352 M. I. F. adit_____________________ 356 Some physical-chemical deductions._______________ 352 High Ore adit__._________________ 357 Field evidence________________________________ 353 Origin of the quartz-rich differentiate _____________ 353 Dewey adit. _____________________________ 357 Summary. _____________________________________ 354 McCoy adit__.__________________ 357 Economic geology_________-____-_________-_-_______- 355 Selected bibliography______________________________ 359 General__ ____________________________________ 355 Index. _________.______________________ 361 ILLUSTRATIONS [Plates 41-44 follow page 332} PLATE 39. Geologic map of La Sal Mountains______________________--_-_--___--___---_-_-_--_-_------_ — __ In pocket 40. Geologic map of the North La Sal stock, La Sal Mountains._---_-- — ________________________________ In pocket 41. Aerial view of North and Middle Mountains. 42. Green Mountain vent breccia. A. Northwest edge. B. East side. 43. View northwest along the vertically sheeted joints in the south part of Beaver Basin. 44. Aerial view of Middle Mountain. 45. Maps of adits in North La Sal Mountain._______________________________________________________ In pocket Page FIGUKE J 05. Index map showing location of the La Sal Mountains, Utah, and other igneous centers on the Colorado Plateau.- 306 106. Sketch of the La Sal Mountains; view from west------------------------------------------------------ 307 107. Generalized map of part of eastern Utah and western Colorado showing relation of the La Sal Mountains to other structural features._________________________________________________________________________ 308 108. Structure contour map of the La Sal Mountains.-- —___----------_--------_----------------------___-- 317 109. Thin sections of diorite porphyry and metadiorite____________________________________________________ 319 110. Thin sections of rocks from the dike-swarm complex in the North La Sal stock-___________________________ 327 111. Filter-press relations at contact between soda syenite porphyry and metadiorite in Snowslide Gulch, Mineral Mountain___________________.___________-----_-----_________-______-___ 329 112. Thin sections of soda syenite porphyry and feldspathoidal rocks, North Mountain.-__--__-__-____________- 330 113. Sketch of Precambrian schist partly replaced by soda syenite porphyry___________________________________ 331 114. Vesiculated syenite porphyry from vent breccia on Green Mountain_-__-_-_---_-__-_-_-__-_-_-___________ 332 115. Thin sections of soda rhyolite and aegirine granite porphyries.________-_______-_-_____-_-_-_-_-___-_-__- 333 116. Thin sections of altered rocks_ ________________________-_-__--___-_----____-_-_---_-_-_-----__----_-_ 336 117. Thin sections illustrating alteration of feldspar.___________________-_-_______-_-___-_--__-_-____--_____ 338 118. View west in Gold Basin______________________-___________---_-___---_-----_-------_--------_-----_- 340 J19. View west across cirque at head of North Fork of La Sal Creek______---_____-_-__--____________--____- 342 120. Graphs showing variations in alkali and silica content of the differentiation sequence in North Mountain. _____ 349 TABLES Page TABLE 1. Chemical analyses of diorite porphyry from the laccolithic mountains on the Colorado Plateau-_____-___--_--__ 321 2. Chemical analyses of monzonite porphyry from the laccolithic mountains on the Colorado Plateau___-__-_- — ___ 324 3. Dimensions, volume, and stratigraphic positions of intrusions
Recommended publications
  • Chapter 1 Section 1

    Chapter 1 Section 1

    COLORADO FLOODPLAIN AND STORMWATER CRITERIA MANUAL CHAPTER 1 GENERAL PROVISIONS SECTION 1 PURPOSE CHAPTER 1 GENERAL PROVISIONS SECTION 1 PURPOSE JANUARY 6, 2006 PURPOSE CH1-100 COLORADO FLOODPLAIN AND STORMWATER CRITERIA MANUAL CHAPTER 1 GENERAL PROVISIONS SECTION 1 PURPOSE TABLE OF CONTENTS 1.1 TITLE ............................................................................................................... CH1-102 1.2 PURPOSE ....................................................................................................... CH1-102 1.3 JURISDICTION................................................................................................CH1-103 1.3.1 VARIANCE PROCEDURES............................................................... CH1-103 CHAPTER 1 GENERAL PROVISIONS SECTION 1 PURPOSE JANUARY 6, 2006 PURPOSE CH1-101 COLORADO FLOODPLAIN AND STORMWATER CRITERIA MANUAL CHAPTER 1 GENERAL PROVISIONS SECTION 1 PURPOSE 1.1 TITLE The criteria and design standards presented herein together with all future amendments and revisions shall be known as the "COLORADO FLOODPLAIN AND STORMWATER CRITERIA MANUAL" (hereafter referred to as Statewide Manual or Manual). 1.2 PURPOSE The overall Manual contents have been prepared and organized into two volumes. Volume I of the Manual contains information and guidelines that are necessary for floodplain and stormwater management practices. Volume II contains guidelines and procedures for floodplain and stormwater engineering analyses and design. The criteria presented in Volume I of the Manual
  • Outreachnotice

    Outreachnotice

    OUTREACH NOTICE USDA FOREST SERVICE INTERMOUNTAIN REGION, R4 Manti-La Sal National Forest Phone (435) 636-3354 Natural Resource Specialist GS-0401-5/7/9 Response requested by December 7, 2016 Position Description The purpose of this outreach notice is to (1) gauge interest in the position, (2) to alert interested individuals of this upcoming employment opportunity. The position is expected to be advertised on www.usajobs.gov/ in the fall of 2016. (Interested persons should respond using the Outreach Response on page 6). The Moab/Monticello Ranger District of the Manti-La Sal National Forest will be seeking to fill two GS-0410-5/7/9 Natural Resource Specialist positions. The duty stations for the position will be Moab, Utah. Duties include but are not limited to the following: Duties: The duties of these position are varied and diverse. One appointee will perform work associated with the Lands and Recreation Special Uses Program, Minerals and Roads Programs and the other appointee will work primarily in the Recreation Program dealing with developed recreation, interpretation and Recreation Special Uses. Compiles material and supply estimates for recreation facilities, maintenance, and operation. Participates in the drafting of annual work action plans for carrying out recreation management 1 decisions. Participates in the implementation of recreation plan objectives and the full range of recreation uses, administration of special authorization for recreation events and concessionaire operations. Inspects campgrounds and other recreation areas to determine that improvements are properly maintained; gathers data for studies of campground use; conducts compliance checks; assists in preparation of recreation reports; and identifies potential recreation sites.
  • Research Natural Areas on National Forest System Lands in Idaho, Montana, Nevada, Utah, and Western Wyoming: a Guidebook for Scientists, Managers, and Educators

    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.
  • OUTREACH NOTICE Forestry Technician, Initial Attack Dispatcher GS-5/6/7 18/8

    OUTREACH NOTICE Forestry Technician, Initial Attack Dispatcher GS-5/6/7 18/8

    OUTREACH NOTICE Forestry Technician, Initial Attack Dispatcher GS-5/6/7 18/8 REGION 4 – MANTI-LA SAL NATIONAL FOREST DUTY STATION: Moab, UTAH POSITION: The Supervisors Office of the Manti-La Sal National Forest will soon be seeking applicants for a Forestry Technician, (Initial Attack Dispatcher), GS-0462-5/6/7 position at the Moab Interagency Fire Center (MIFC). This is a permanent part-time position (18/8) with the duty station in Moab, Utah. DUTIES: This position is located at MIFC where the incumbent will be an Initial Attack Dispatcher for the interagency center and assist with other fire center duties as assigned. The Moab Interagency Fire Center represents the five wildland fire agencies in Southeastern Utah, providing resource coordination between the Manti-La Sal National Forest, Division of Forestry, Fire and State Lands, Bureau of Land Management, National Park Service and Bureau of Indian Affairs. The MIFC dispatch area involves nearly 10 million acres of terrain that ranges from grasslands at 4,000 feet to forested lands above 10,000 feet in elevation. Land status throughout the area is highly fragmented. Resources include two 10-person crews, 11 engines and 1 Type 3 Helicopter with crew and the Red Rock Regulars (Type 2 IA Handcrew). MIFC resources respond to an average of 200 to 400 incidents per year, with a fire season that extends from March through Mid November. This position is located in an initial attack fire suppression organization where the employee performs a variety of staff and administrative duties relating to fire suppression activities and the support of fire management programs.
  • Frontier in Transition : a History of Southwestern Colorado

    Frontier in Transition : a History of Southwestern Colorado

    BLM LIBRARY 88014165 FRONTIER IN TRANSITION PAUL M. ,6F(pURKE A ffifflSTCDISW ©IF c 3®aJTT[H]M[ES iriSISI (C©L©IBAID)® TODSLEMJ (Q)LP (OTLLCM^ffi)® CULTURAL RESOURCES SERIES DUMBER TEN Bureau of Land Management Library g. 50, Denver Federal Center Denver, CO 8G225 FRONTIER IN TRANSITION A HISTORY OF SOUTHWESTERN COLORADO by Paul M. O'Rourke BUREAU OF LAND MANAGEMENT LIBRARY Denver, Colorado 88614165 Colorado State Office Bureau of Land Management U °fLandMana8ement 19eo LX B'dg. 50, Denver Feriorai r„ . 6nter Denver, CO 80225 COPIES OF THIS REPORT ARE AVAILABLE FROM: BUREAU OF LAND MANAGEMENT COLORADO STATE OFFICE RM. 700, COLORADO STATE BANK BUILDING 1600 BROADWAY DENVER, COLORADO 80202 FOREWORD This study represents the tenth volume in a series of cultural resource studies. It was prepared as part of the Bureau of Land Management's Cultural Resource Manage- ment Program and is the second complete history of a BLM district in Colorado. A major objective of the Bureau of Land Management, Department of the Interior, is the identification, evaluation and protection of the nation's historic heritage and values, particularly those under the management of the Bureau. The history of Southwestern Colorado is designed to provide a baseline narrative for Cultural Resource Management. Paul M. O'Rourke has written a new history of the southwest corner of Colorado and in doing so, has provided a timely and original view of Colorado's heritage and history. This study will become part of the over-all history of Colorado as prepared by the Bureau and as other volumes dealing with Colorado history are written, they too will be made available to the general public.
  • Implications for Porphyry Mo Genesis

    Implications for Porphyry Mo Genesis

    ©2013 Society of Economic Geologists, Inc. Economic Geology, v. 108, pp. 987–1013 The Metal Content of Silicate Melts and Aqueous Fluids in Subeconomically Mo Mineralized Granites: Implications for Porphyry Mo Genesis LINDA LERCHBAUMER† AND ANDREAS AUDÉTAT Bayerisches Geoinstitut, Universität Bayreuth, 95440 Bayreuth Abstract To better understand the factors leading to porphyry Mo mineralization, we studied melt and fluid inclusions in three subeconomically Mo mineralized granites in well-known Mo provinces: the Treasure Mountain dome in the Colorado mineral belt (USA), and the Drammen and Glitrevann granites in the Oslo rift (Norway). Melt and fluid inclusions were investigated in samples ranging from coarsely crystallized whole rocks to euhedral quartz crystals within miarolitic cavities. The major and trace element chemistry of individual inclusions was determined by laser ablation-inductively coupled plasma-mass spectrometry. Melt inclusions are rhyolitic in composition and record a clear trend of increasing Mo concentrations with increasing degree of melt differen- tiation as monitored by Cs, extending from ~5 to 10 ppm Mo at 5 ppm Cs to ~17 to 40 ppm Mo at 100 ppm Cs. Coexisting magmatic fluids were single phase, had a salinity of 4 to 6 wt % NaCl equiv and a density of 0.6 3 to 0.7 g/cm , and contained ~0.5 wt % S and up to 6 mol % CO2. Molybdenum concentrations in these fluids ranged from ~20 to ~200 ppm Mo, except for some highly evolved fluids that had lower Mo contents. Comparison of our data with published fluid and melt inclusion data from porphyry Mo deposits, porphyry Cu (Mo, Au) deposits, and barren intrusions reveals that most subduction-related magmas have lower Mo/Cs ratios than within-plate magmas, but that within these two groups there are no systematic differences between barren and productive intrusions.
  • Lands Suitable for Timber Management

    Lands Suitable for Timber Management

    C a S r l a en C Hefty, Mount d k Bushnell Hill z e g Fro r e e e C r k T ree r C C C e olts e r n C k e h e e k k e en e h Tuchuck Mountain r is ek C K re e n C T c tio u a r rv p Sta Th S om a Cr Creek eek Johnson T uc hu ck C T r rail C Bald Mountain ee reek k k e T ek e re r N t C C o Yakinikak Creek ef a k l tl i C o Trailcreek in C k ! Twin Buttes e Cleft Rock Mountain K re e k e r e k C e A T r o C k m o e d k r e a Lewis, Mount S o l ek F a e Cr Wedge Mountain C y r tle e n T e A k Hornet MountainHorne t Creek N Tepee Creek in T Thompson-Seton, Mount k o C T r ee In k u K y oop T a ee Cr Babb C eek Whale Buttes ! re Center Mountain e k k e TT re t Akinkoka Peak n C e m a ge k k na k e o a ree T M C e k k r e e le r n e b ha i r m C i W k T Locke, Mount C se r o o A f o y le M b t ta i Red Buttes T r Su H o ds a n w h La k S Cr eek Huntsberger Peak T Young, Mount T Nasukoin Mountain k n T e a k l e e t P e r s r re C C o F w e 6 c 8 o 9 Hoodoo Hill d u 1 Lake Mountain ea pr S M S p ed rin T R g C re Fortine ek ! T Polebridge !@ Link Mountain ! Ha WhiteTfish Mountain y C re ek Wetzel T ,000 ! k 5 ree 7 n C 1 ra : Mo 1 k e e k .
  • Acrobat Distiller, Job 6

    Acrobat Distiller, Job 6

    Magmatism in Western Cascades Arc Early Tertiary Magmatism • Active from 38 to 17 Ma • New volcanic activity west of Clarno Fm Part II and south into Oregon Reference: • Western Cascade volcanism was mostly andesitic DNAG v. 3, Ch. 7, pp 294-314 • Some rhyolitic ash-flow sheets • Broad curving continuous belt of volcanoes Cascade-John Day Washington Magmatism • Overlapped older Challis and Tuscarora belts – Numerous shallow batholiths – Snowqualamie Batholith – Tatoosh Pluton • Represent subvolcanic magmatism • Younger High Cascades follows the same trend Western Oregon Southern Oregon • Oligocene calc-alkaline volcanic rocks • No units younger than 17 Ma present – Unconformable on Eocene rocks • Mafic alkalic rocks developed in • Andesite-dacite-rhyolite erupted from front of the western Cascades numerous centers • Nepheline syenite, Camptonite, • Few shallow subvolcanic intrusives Ferrogabbro 1 Cascade-John Day Northern California • Basaltic to rhyolitic volcanism • Age range of 31 to 20 Ma • Andesite mudflow breccias in Sierra foothills – Cedarville Volcanics – Extend into Nevada – Andesite breccias and rhyolite tuffs Cascade-John Day John Day Magmatic Region • Age of 36 to 18 Ma • Much downwind fall out from Western Cascades volcanism • High-silica, alkali rhyolite is common • Local alkali basalt to trachyte eruptions Southern Oregon Other Locations • Rhyolite to bimodal rhyolite- • Lovejoy basalt in California trachyandesite – Alkali basalts and trachyandesites • Summer lake, Goose Lake, Albert Rim • Owyhee Mountains, Idaho – Rhyolites
  • Triangulation in Utah 1871-1934

    Triangulation in Utah 1871-1934

    UNITED STATES DEPARTMENT OF THE INTERIOR Harold L. Ickes, Secretary GEOLOGICAL SURVEY W. C. Mendenhall, Director Bulletin 913 TRIANGULATION IN UTAH 1871-1934 J. G. STAACK Chief Topographic Engineer UNITED STATES GOVERNMENT PRINTING OFFICE WASHINGTON: 1940 Tor sale by the Superintendent of Documents, Washington, D. C. Price 20 cents (paper) CONTENTS Page Introduction ______________________________________________________ 1 Scope of report------__-_-_---_----_------------ --__---__ _ 1 Precision __ _ ________________________ _ __________________ _ ___ 1 Instruments used._ _ _ _ _ _ _ _ _ 2 Station marks___- _ _.__ __ __ _ 2 Datum_-_-_-__ __________________________ ______ ______-___.__ 3 Methods of readjustment..._____.-.__..________.___._._...___.__ 4 Form of results__-.________________________ _.___-_____.______ 5 Arrangement__.______________________________ _ ___ _ ________ 6 Descriptions of stations._______________________________________ 6 Azimuths and distances.__ ____-_.._---_--_________ -____ __ __ ^ 7 Maps.__----__-----_-_---__-_--_-___-_-___-__-__-_-_-___.-.__ 7 Personnel_ _ __-----_-_-_---_---------_--__-____-__-_.--_.___ . 7 Projects 9 Uinta Forest Reserve, 1897-98_ 9 Cottonwood and Park City special quadrangles, 1903____ _ 19 Iron Springs special quadrangle, 1905____________________________ 22 Northeastern Utah, 1909.. -_. 26 Eastern Utah, 1910 - . 30 Logan quadrangle, 1913._________-__-__'_--______-___:_____.____ 42 Uintah County, 1913___-__. 48 Eastern Utah, 1914.. ... _ _ .. 55 Northern Utah, 1915 (Hodgeson)_____-___ __-___-_-_-__-_--. _. 58 Northern Utah, 1915 <Urquhart)_.
  • Summits on the Air – ARM for the USA (W7A

    Summits on the Air – ARM for the USA (W7A

    Summits on the Air – ARM for the U.S.A (W7A - Arizona) Summits on the Air U.S.A. (W7A - Arizona) Association Reference Manual Document Reference S53.1 Issue number 5.0 Date of issue 31-October 2020 Participation start date 01-Aug 2010 Authorized Date: 31-October 2020 Association Manager Pete Scola, WA7JTM Summits-on-the-Air an original concept by G3WGV and developed with G3CWI Notice “Summits on the Air” SOTA and the SOTA logo are trademarks of the Programme. This document is copyright of the Programme. All other trademarks and copyrights referenced herein are acknowledged. Document S53.1 Page 1 of 15 Summits on the Air – ARM for the U.S.A (W7A - Arizona) TABLE OF CONTENTS CHANGE CONTROL....................................................................................................................................... 3 DISCLAIMER................................................................................................................................................. 4 1 ASSOCIATION REFERENCE DATA ........................................................................................................... 5 1.1 Program Derivation ...................................................................................................................................................................................... 6 1.2 General Information ..................................................................................................................................................................................... 6 1.3 Final Ascent
  • Slickrock Foot Trail Provides an Opportunity for Beginners to Orient Themselves Dominating the Rest of the Scene Is the to Trails in Canyonlands National Park

    Slickrock Foot Trail Provides an Opportunity for Beginners to Orient Themselves Dominating the Rest of the Scene Is the to Trails in Canyonlands National Park

    Viewpoint 3 Viewpoint 4 Lower Little Spring Canyon Big Spring Canyon Slickrock Gifts from the Sea A Monumental Change The gray and purple rock layers visible in Grand View Point and Junction Butte, rising Foot Little Spring Canyon contrast sharply with a thousand feet above Big Spring Canyon, are the red and white rock that dominates most visible to the north. These landmarks show of The Needles district. Both, however, were erosional patterns typical of sedimentary derived from the same source — the ocean. rock. The various layers exhibit different Trail Millions of years ago this area was covered by degrees of resistance to weathering. Softer a shallow sea. Little Spring Canyon is pre- rocks, such as shales and mudstones, crumble TRAIL GUIDE dominately limestone, a hard sedimentary into slopes. Sandstones, limestones and other rock composed mostly of calcium harder rocks maintain vertical bluffs. The carbonate, the hard parts of massive Wingate cliffs, the most prominent tiny marine animals that layer, were once enormous sand dunes. settled to the ocean floor as they died. Fossilized The Canyonlands region re- remains of crinoids, mained near sea level during brachiopods and other the time these rock layers Navajo Ss. Brachiopod marine invertebrates were deposited. Change Kayenta Fm. give testimony came when massive forces to the ocean’s within the earth pushed Wingate Ss. Crinoid presence. these layers upward, forming the Monument The spires of The Needles district display Uplift and causing the Chinle Fm. the red-and-white banding of Cedar Mesa rock layers to fracture. Sandstone, which was formed as sandy Cracks and joints Moenkopi Sh.
  • My Interest in Amygdules and Cavity-Fill

    My Interest in Amygdules and Cavity-Fill

    BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA VOL. 41, PP. 383-404.4 FIGS. SEPTEMBER 30,1930 AMYGDULES AND PSETJDO-AMYGDULES1 BY FREDERICK K. MORRIS (Bead before the Geological Society December 26, 1929) CONTENTS Page Introduction ..................................................................................................................... 388 Classes of cavities arid cavity-fillings in igneous rocks................................... 384 Comments on certain te rm s........................................................................................ 385 Amygdaloidal dikes of the Liukiang coal field...................................................... 386 Coal-penetrated dike near C hinw angtao............................................................... 391 Amygdaloidal dikes of the Linsi coal field........................................................ 392 H si Shan am ygdaloid.................................................................................................... 394 The flow near N iangniang M iao............................................................................. 396 O ther examples of filling and pseudo-amygdules................................................ 397 Fillings in the norites of T sin an fu ........................................................................... 401 Amygdaloidal dike in Gasp6....................................................................................... 403 Conclusions ....................................................................................................................