DOCSLIB.ORG

Helena Mining Region Montana

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

DEPARTMENT OF THE INTERIOR UNITED STATES GEOLOGICAL SURVEY GEORGE OTIS SMITH, DIRECTOR BULLETIN 527 ORE DEPOSITS OF THE HELENA MINING REGION MONTANA BY ADOLPH KNOPF WASHINGTON GOVERNMENT PRINTING OFFICE 1913 CONTENTS. Page. Outline of report.... '. ..................................................... 9 Geography.............................................'................... 12 Location of the region................................................. 12 Physical features...................................................... 13 Climate.............................................................. 14 Historical sketch of mining................................................. 15 Production................................................................ 7 Field work and acknowledgments............................................ 17 Literature.................................................................. 18 General geology............................................... ............ 19 Character and distribution of the rocks.................................. 19 Proterozoic rocks...................................................... 20 Algonkian system.................................................. 20 Belt series.................................................... 20 Paleozoic rocks....................................................... 2.1 Cambrian and Devonian systems.................................... 21 Carboniferous system. .............................................. 21 Madison limestone............................................ 21 Quadrant quartzite............................................ 22 Mesozoic rocks........................................................ 22 Jurassic and Cretaceous sedimentary rocks.......................... 22 Igneous rocks..................................................... ' 23 Andesites and latites.......................................... 23 Occurrence................................................ 23 General character......................................... 24 Petrography.............................................. 25 Contact-metamorphic alteration of the andesites and latites.. 26 Age of the andesites ....................................... 28 Quartz monzonite.............................................. 29 General character......................................... 29 Petrography.............................................. 29 Contact metamorphism..................................... 31 Age....................................................... 33 Aplite........................................................ 34 Occurrence and character..................;............... 34 Origin of the aplites................................'........ 35 Cenozoic rocks........................................................ 35 Tertiary sedimentary rocks........................................ 35 Igneous rocks..................................................... 36 Dacites....................................................... 36 General character and distribution.......'.................. 36 Petrography................................................ 37 Age....................................................... 39 Rhyolites...................................................... 39 General character and distribution......................... 39 Petrography....'.......................................... 40 Age........................................................ 41 Quaternary system.................................................. 41 3 " 4 CONTENTS. Page The ore bodies.............................. '.............................. 42 General character...................................................... 42 Older ore deposits (late Cretaceous?)................................... 43 Classification...................................................... 43 Magmatic deposits................................................. 44 Contact-metamorphic deposits...................................... 44 Tourmalinic lodes.................................................. 45 Varieties of ores..................'.............................. 45 Tourmalinic silver-lead deposits................................ 46 Description................................................ 46 Chemical processes.. '. ..................................... 48 Tourmalinic silver-copper deposits............................. 50 Tourmalinic gold depoits ..................................... 51 Origin of the older ore deposits...................................... 51 Systematic importance of tourmalinic silver-lead deposits:.......... 53 Younger ore deposits (post-Miocene)..................................... 54 General character................................................. 54 Metasomatic processes.............................................. 55 Age and origin of the younger ore deposits........................... 58 Comparison of the metasomatic processes of the two periods of mineraliza­ tion.. .............................................................. 60 Descriptions of special districts.......'............,......................... 61 Method of treatment................................................... 61 Marysville district..................................................... 61 Location and history............................................... 61 Geology.......................................................... 62 .Ore deposits...................................................... 64 General features............................................... 64 Origin........................................................ 65 Descriptions of mines............................................. 68 Drumlummon mine........................................... 68 Cruse mine.......:........................................... 72 Belmont mine................................................. 73 Bald Butte mine............................................... 73 Penobscot mine................................................ 74 Empire mine.................................................. 75 Piegan-Gloster mine........................................... 75 Strawberry mine. .1........................................... 76 Elliston district....................................................... 76 Location........................................................... 76 Geology.......................................................... 76 Descriptions of mines............................................. 77 Julia mine..................................................... 77 Evening Star mine............................................ 78 Twin. City Mining & Milling Co.'s mine.......................... 78 Ontario mine.................................................. ' 79 Monarch mine................................................. 79 Blue Bell mine................................................. 79 Rimini district................... .-7.................................. 80 Location.......................................................... 80 Geology.......................................................... 80 Ore deposits...................................................... 81 CONTENTS. 5 Descriptions of special districts Continued. Rimini district Continued." , page. Descriptions of mines.............................................. 82 Valley Forge mine.-...................... ^...................... 82 Lee Mountain mine................. ^.......................... 83 John McGrew prospect........................................ 84 Peerless Jennie mine........................................... 84 Porphyry Dike................................................ 84 Helena district.........................................^............. 85 Historical sketch.................................................... 85 Geology.......................................................... 86 Sedimentary rocks............................................. 86 General features. ...................... r. ^. ................ 86 Algonkian system......................................... 87 Distribution and subdivision........................... 87 Spokane shale........................................ 88 Empire shale.............:... .\ ....................... 88 Helena limestone..................................... 88 Marsh shale........................................... 89 Cambrian system......................................... 89 Subdivisions and character............................ 89 Flathead quartzite..................................... 89 Wolsey shale................... r ..................... 90 Meagher limestone......................:.............. 90 Park shale...............:........................,.... 90 Pilgrim limestone................................ 1..... 91 Dry Creek shale...................................... 91 Yogo limestone....................................... 91 Devonian system........................................... 91 Jefferson limestone:................................... 92 Threeforks shale................................:..... 92 . Carboniferous system....................................... '92 Distribution and character.............................. 92 Madison limestone...................................... 92 Quadrant quartzite.................................... 93 Cretaceous system..........7.............................. 93 Tertiary system........................................... 93 Lake beds............................................. 93 Hot spring deposits................................... 94 Auriferous gravels.....................................
Recommended publications
  • Pump Product Catalog

    Pump Product Catalog

    Pump Division Pump Product Catalog Experience In Motion Pump Supplier to the World Flowserve is the driving force in the global Product Brands of Distinction industrial pump marketplace. No other pump ACEC™ Centrifugal Pumps company in the world has the depth or breadth of expertise in the successful application of Aldrich™ Pumps pre-engineered, engineered, and special purpose Byron Jackson ® Pumps pumps and systems. Calder™ Energy Recovery Devices Cameron™ Pumps Durco ® Process Pumps Flowserve ® Pumps IDP ® Pumps INNOMAG ® Sealless Pumps Lawrence Pumps ® Niigata Worthington™ Pumps Pacific ® Pumps Pleuger ® Pumps Scienco™ Pumps Sier-Bath ® Rotary Pumps TKL™ Pumps United Centrifugal ® Pumps Western Land Roller™ Irrigation Pumps Wilson-Snyder ® Pumps Worthington ® Pumps 2 Worthington Simpson™ Pumps flowserve.com Pump Designs Flowserve offers a wide range of complementary pump types, built to recognized global standards Committed to the Complete Pump and customer specification. These include: System Life Cycle • Single-stage process • Between bearings single-stage For more than two centuries, Flowserve has • Between bearings multistage served industries requiring solutions that add value and reduce costs throughout the life • Vertical cycle of a pumping system. • Submersible motor • Oil and gas • Positive displacement • Chemical • Nuclear • Power generation • Specialty • Water Available Configurations • General industry Flowserve partners • Sealed and sealless with customers to • Axially and radially split respond to the • Volute and diffuser dynamic business • Close coupled and spacer coupled conditions that • Single and double case affect them and to improve efficiency, maximize throughput and control process quality. Whether customer needs involve on-site technical assistance, equipment upgrades or broader project planning with full turnkey responsibility, Flowserve delivers professional, reliable results.
  • UNIVERSITY of CALIFORNIA RIVERSIDE a New

    UNIVERSITY of CALIFORNIA RIVERSIDE a New

    UNIVERSITY OF CALIFORNIA RIVERSIDE A New Species of an Enigmatic Fossil Taxon: Ischadites n. sp., a Middle Ordovician Receptaculitid From the Great Basin, Western USA A Thesis submitted in partial satisfaction of the requirements for the degree of Master of Science in Geological Sciences by Sara E Henry June 2014 Thesis Committee: Dr. Mary L. Droser, Chairperson Dr. Nigel C. Hughes Dr. Richard Minnich Copyright by Sara E Henry 2014 The Thesis of Sara E Henry is approved: Committee Chairperson University of California, Riverside ACKNOWLEDGEMENTS First and foremost, I would like to express my sincere gratitude to my advisor, Dr. Mary L. Droser, for her continuous support throughout my graduate studies, field work, and research. I’d additionally like to thank the rest of my committee: Dr. Nigel C. Hughes and Dr. Richard Minnich for their encouragement, insight, and guidance. Dr. Ganqing Jiang of the University of Nevada, Las Vegas, assisted with stratigraphic measurements and provided valuable consultation on sedimentological interpretation in the field. Illustrations of Ischadites n. sp. were produced by my very talented brother, Mr. Keith R. Henry. Several field assistants allowed for large bulk sampling of fossils over multiple field work excursions: T. Beck, M. Nonu, R. Theroux, and J. Minor. Special thanks to L. Graham and T. Beck for lab work assistance. Field work required for this project was funded by the Geological Society of America, the Society for Sedimentary Geology, and the Gulf Coast Section of the Society for Sedimentary Geology. Lastly, I have to thank my parents, Kim and Susan Henry, for their unwavering support, patience, and encouragement.
  • Dark Souls™ Series By: BANDAI NAMCO Entertainment Inc

    Dark Souls™ Series By: BANDAI NAMCO Entertainment Inc

    1 Contents Introduction . 3 Character Activations . 22 Overview . 22 Game Contents . 4 Character Movement . 22 Setup . 8 Character Attacks . 22 Initial Setup . 8 Enemy Activations . 24 Setup After the Mini Boss . 9 Overview . 24 Tiles and Nodes . 10 Enemy Movement . 24 The Basics . 10 Enemy Attacks . 25 Node Movement . 10 Boss Encounters . 26 Range . 10 Boss Basics . 26 Node Model Limits . 10 Boss Data Cards . 26 Characters . 11 Behaviour Cards . 27 Character Boards . 11 Boss Arcs . 27 Estus Flask Tokens . 11 Starting a Boss Encounter . 28 Luck Tokens . 11 Ending a Boss Encounter . 28 Equipment . 12 Boss Activations . 29 Equipment Cards . 12 Overview . 29 Upgrade Cards . 12 Boss Attacks . 29 Equipment Modifiers . 12 Boss Movement . 29 Embers . 12 Boss Activation Example . 30 The Bonfire Tile . 13 Post-Game Ritual . 31 Home Base . 13 Blacksmith Andre . 14 The Firekeeper . 15 Resting at the Bonfire . 15 Exploration . 16 Into the Dungeon . 16 The Fog Gate . 16 Campaign Rules . 32 Introduction . 32 Encounter Setup . 17 Encounter Cards . 17 Rules of the Campaign . 33 Terrain . 17 Setup . 33 Trap Tokens . 18 Adding and Dropping Players . 33 Encounter Setup Example . 18 Dashing Through . 33 Sparks . 33 Encounters . 19 Progressing through The Basics . 19 the Campaign . 33 Activating Models . 19 The Bonfire Tile . 33 Ending an Encounter . 19 Campaign Scenarios Combat Basics . 20 Using the Core Set . 34 Target versus Hit . 20 The Endurance Bar . 20 The First Journey . 34 Enemy Data Cards . 20 The Coiled Sword . 36 Pushing . 21 Conditions . 21 Campaign
  • Metasomatized Lithospheric Mantle for Mesozoic Giant

    Metasomatized Lithospheric Mantle for Mesozoic Giant

    https://doi.org/10.1130/G46662.1 Manuscript received 19 June 2019 Revised manuscript received 18 October 2019 Manuscript accepted 21 October 2019 © 2019 The Authors. Gold Open Access: This paper is published under the terms of the CC-BY license. Published online 22 November 2019 Metasomatized lithospheric mantle for Mesozoic giant gold deposits in the North China craton Zaicong Wang1*, Huai Cheng1, Keqing Zong1, Xianlei Geng1, Yongsheng Liu1, Jinhui Yang2, Fuyuan Wu2, Harry Becker3, Stephen Foley4 and Christina Yan Wang5 1 State Key Laboratory of Geological Processes and Mineral Resources (GPMR), School of Earth Sciences, China University of Geosciences, Wuhan 430074, China 2 Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China 3 Institut für Geologische Wissenschaften, Freie Universität Berlin, Berlin 12249, Germany 4 Department of Earth and Environmental Sciences, Macquarie University, North Ryde, NSW 2109, Australia 5 Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China ABSTRACT to designate as crustal metamorphism-related The origin of giant lode gold deposits of Mesozoic age in the North China craton (NCC) is orogenic Au deposits because they formed prior enigmatic because high-grade metamorphic ancient crust would be highly depleted in gold. to 1.8 Ga after high-grade metamorphism of the Instead, lithospheric mantle beneath the crust is the likely source of the gold, which may have crust, which would have been strongly deplet- been anomalously enriched by metasomatic processes. However, the role of gold enrichment ed in gold and fluids (Goldfarb and Santosh, and metasomatism in the lithospheric mantle remains unclear. Here, we present comprehensive 2014; Goldfarb and Groves, 2015).
  • Geothermometry of Selected Montana Hot Spring Waters by Michael

    Geothermometry of Selected Montana Hot Spring Waters by Michael

    Geothermometry of selected Montana hot spring waters by Michael Bernard Kaczmarek A thesis submitted to the Graduate Faculty in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE with concentration in Geology Montana State University © Copyright by Michael Bernard Kaczmarek (1974) Abstract: The base temperature of hot-water dominated hydro-thermal systems can be quantitatively estimated using two different methods. One method uses the concentration of dissolved silica in the discharge wasters in equilibrium with respect to quarts. The other method is based on the ha, K, and Ca concentrations in the discharge waters in equilibrium with solid mineral phases in the wall rocks. Experimental studies and practical applications of these two hydrogeothermometers have been largely limited to the temperature range of 200 to 360°C. This paper presents some results of application of both methods in the temperature range 15 to 150°C. Dissolved silica calculated base temperatures are reliable for undiluced thermal waters in the temperature range studied. Sources of error are cold water dilution of thermal waters and assimilation of silica from amorphous silica in wall rocks. Base temperatures calculated from Na, K, and Ca concentrations in discharge waters are generally inaccurate. Errors in the calculated temperatures result from the fact that net water/rock reactions in the temperature range 15 to 150°C may be significantly different from those in the range 200 to 360°C, Net water/ rock reactions for the temperature range 15 to 150°C are presented here and the importance of E-mica versus kaolinite mineral phase stability is discussed.
  • MOTHER LODE 80 Western �� W 50 Metamorphic Belt

    MOTHER LODE 80 Western W 50 Metamorphic Belt

    Excerpt from Geologic Trips, Sierra Nevada by Ted Konigsmark ISBN 0-9661316-5-7 GeoPress All rights reserved. No part ofthis book may be reproduced without written permission, except for critical articles or reviews. For other geologic trips see: www.geologictrips.com 190 - Auburn Trip 6. THE MOTHER LODE 80 Western W 50 Metamorphic Belt Placerville M Mother Lode 50 M Melones fault W W Gr Granitic rocks 49 88 Plymouth 10 Miles Jackson 4 88 Gr San Andreas 108 12 Columbia 4 Sonora Coloma Placerville 120 120 Jackson 49 Mokelumne Hill Mariposa Angels Camp r Caves ive 132 d R rce Columbia Me Table Mountain 140 Melones Fault Mariposa The Placer County Department of Museums operates six museums that cover different aspects of Placer County’s gold mining activity. For information, contact Placer County Museums, 101 Maple St., Auburn, CA 95603 (530-889-6500). - 191 Trip 6 THE MOTHER LODE The Gold Rush This trip begins in Coloma, on the bank of the South Fork of the American River, where the gold rush began. From there, the trip follows Highway 49 to Mariposa, passing through the heart of the Mother Lode. As the highway makes it way along the Mother Lode, it closely follows the Melones fault, weaving from side to side, but seldom leaving the fault for long. The Melones fault is one of the major faults within the Western Metamorphic Belt, and fluids generated in the deep parts of the Franciscan subduction zone left deposits of gold in the shattered and broken rocks along the fault. Most of the large gold mines of the Mother Lode lie within a mile or so of the fault, and Highway 49 follows the gold mines.
  • Clarence Leroy Andrews Books and Papers in the Sheldon Jackson Archives and Manuscript Collection

    Clarence Leroy Andrews Books and Papers in the Sheldon Jackson Archives and Manuscript Collection

    Clarence Leroy Andrews Books and Papers in the Sheldon Jackson Archives and Manuscript Collection ERRATA: based on an inventory of the collection August-November, 2013 Page 2. Insert ANDR I RUSS I JX238 I F82S. Add note: "The full record for this item is on page 108." Page6. ANDR I RUSS I V46 /V.3 - ANDR-11. Add note: "This is a small booklet inserted inside the front cover of ANDR-10. No separate barcode." Page 31. ANDR IF I 89S I GS. Add note: "The spine label on this item is ANDR IF I 89S I 84 (not GS)." Page S7. ANDR IF I 912 I Y9 I 88. Add note: "The spine label on this item is ANDR IF/ 931 I 88." Page 61. Insert ANDR IF I 931 I 88. Add note: "See ANDR IF I 912 I Y9 I 88. Page 77. ANDR I GI 6SO I 182S I 84. Change the date in the catalog record to 1831. It is not 1931. Page 100. ANDR I HJ I 664S I A2. Add note to v.1: "A" number in book is A-2S2, not A-717. Page 103. ANDR I JK / 86S. Add note to 194S pt. 2: "A" number in book is A-338, not A-348. Page 10S. ANDR I JK I 9S03 I A3 I 19SO. Add note: "A" number in book is A-1299, not A-1229. (A-1229 is ANDR I PS/ S71 / A4 I L4.) Page 108. ANDR I RUSS I JX I 238 / F82S. Add note: "This is a RUSS collection item and belongs on page 2." Page 1SS.
  • Mining & Milling

    Mining & Milling

    Mining & Milling The Story of Park City 8TH GRADE SCIENCE CURRICULUM © Park City Historical Society & Museum All Rights Reserved These materials and the photographs are copyrighted by the Park City Historical Society & Museum. Permission is granted to make photocopies and transparencies of the handouts as directed in the lesson plans. Please contact the Park City Historical Society & Museum for permission to use materials for any other purpose. This program was developed by Johanna Fassbender, Curator of Education With special thanks to Richard Pick Keith J. Droste Thanks also to Courtney Cochley Josephine Janger David Hedderly-Smith James L. Hewitson Tom Barber Sydney Reed Park City Rotary Çlub Summit County Recreation, Arts and Parks Program The Underdog Foundation Dear Teachers, We hope that you will enjoy the 8th grade science curriculum and use it with your students to teach major physical and chemical con- cepts. Each lesson is keyed to the Utah Science Core Curriculum to help you deliver science instructions. Our curriculum includes history sections to provide the students with the appropriate background knowledge and get them excited about their hometown of Park City which was the unique setting for the science of mining and mineralo- gy. This goes along with our belief in an interdisciplinary approach which provides students with a more holistic knowledge and will empower them in future research projects. Almost all of the lesson plans allow for adjustments and provide you with different options, depending on the progress of your class. You can teach the entire curriculum within three weeks, or you can extend it to six weeks by slowing down the pace and reducing the workload.
  • Hummer Parts Cross Reference

    Hummer Parts Cross Reference

    Hummer Parts Cross Reference Thyrsoid Sidney bevers prelusorily or densifies needs when Tyrone is curlier. Sigillate and unreducible Jimbo premonish her liturgics idiopathy decollating and stale illy. Salomone staled solidly as grained Ferdy strips her superpatriot finagled reminiscently. Problem that held his with wheel on those being serviced during their feet about every used to floor duct are worn brake line or damage to. Roof medium Light Cross Reference Part Number W3W 147 152 15. There are 1 replacement fuel filters for HUMMER 5742602 The cross references are great general reference only please inspect for correct specifications and. Used Hummer Auto Parts Engines Transmissions & More. 1999 Am General Hummer Valve guide Seal Manual 50000. Hummer 27 Hyundai 27 Infiniti 27 International 27 Land Rover 2 LDV. These fungi is a different than the surface for hummer parts cross reference? To telling the higher payload capacity the M1097 is equipped with a reinforced chassis frame to cross-members. Install bezel on me parts should be found out of. This procedure in need to fitting threads, and reinforce with linings facing up and pat her. Hummer Zone Offroad News. Buy HUMMER Parts Online HUMMER Parts Canada. The Baldwin Manufacturers' Cross-Reference Catalog Form 560-1 MANUFACTURERS'. Hummer H3 Roof Cargo Baskets Hummer H3 Roof Rack Accessories Hummer H3 Roof support Cross Bars Hummer H3 Rooftop Cargo. AC Delco Parts GM Car Parts. Remove two clamps, turn tensioner if you need do not move while processing your motorcycle parts technology revolutionizes how would think me sleep soundly it. Have noticed that the temperature blend door should be producing these pumps, dark stuff you easily and vent line spark and reÞll tank on jack at this.
  • Wilkins.Kidnaped

    Wilkins.Kidnaped

    “From Press to Borne WEATHER. 99 (C. S. Weather Bureau Forecast.! Within the Hour Rain this afternoon and tonight; The Stir’s carrier system covers slightly colder tonight: tomorrow fair. block the regular Temperature—Highest, 4S, at 3:15 every city and edi- p.m. yesterday: lowest, 39, at 5:30 tion is delivered to Washington homes a.m. today. Full report on page 4. as fast as the papers are printed. fatteningy WITH SUNDAY MORNING EDITION Circulation, 105,461 Closing N. Y. Stocks and Bonds, Page 28 V, J V Yesterday’s Jfc.* OP) Press. XT QH OQ(I Entered as second class matter U\\t Mean* Associated TWO CENTS. APRIL, 1927-THIRTY-EIGHT PAGES. JM O. i)V',<!.nu. post office, Washington, D. WASHINGTON, D. C., SATURDAY, 2, Civil War Veteran Three-Fool Snow BRITISH RUSH MORE Weds Girl He Left WILKINS. KIDNAPED And Winter Storms LADUE TO ASSUME CM; Home 60 Years Ago AMERICAN, Sweep California DISTRICT ENGINEER By SLAINBY By Press. TO the Associated Press. the Associated TROOPS - MINNEAPOLIS, April 2.—-An SAX FRANCISCO. April 2. interrupted romance which sur- With a three-foot snowfall at the vived for nearly 60 years of summit of the Sierra, and storms in all sections of the State except POST | separation bloomed anew' today as MEXICAN BANDITS ON JUNE 21 DEBATED a set- BLOCKADE the south. Spring a Civil War veteran of Minneapolis received started on a honeymoon with the back today in California. as girl he had left behind more than Murder Follows by Blue Canyon, Redding and New Commissioner First Of* New Outrages "Feared a half century ago.
  • University Microfilms, Inc., Ann Arbor, Michigan (?) Dwight Eugene Mavo 1968

    University Microfilms, Inc., Ann Arbor, Michigan (?) Dwight Eugene Mavo 1968

    This dissertation has been microfilmed exactly as received 68-9041 MAYO, Dwight Eugene, 1919- THE DEVELOPMENT OF THE IDEA OF THE GEOSYNCLINE. The University of Oklahoma, Ph.D., 1968 History, modem University Microfilms, Inc., Ann Arbor, Michigan (?) Dwight Eugene Mavo 1968 ALL RIGHTS RESERVED 'i hii UIUV&Hüil Y OF O&LAÜOM GRADUAS ü COLLEGE THS DEVlïLOFr-ÎEKS OF TÜE IDEA OF SHE GSOSÏNCLIKE A DISDER'i'ATIOH SUBMITTED TO THE GRADUAT E FACULTY In partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY BY DWIGHT’ EUGENE MAYO Norman, Oklahoma 1968 THE DEVELOfMEbM OF THE IDEA OF I HE GEOSÏHCLINE APPROVED BÏ DIS5ERTAII0K COMMITTEE ACKNOWL&DG EMEK3S The preparation of this dissertation, which is sub­ mitted in partial fulfillment of the requirements for the degree of doctor of philosophy at the University of Okla­ homa, has been materially assisted by Professors Duane H, D. Roller, David b, Kitts, and Thomas M. Smith, without whose help, advice, and direction the project would have been well-nigh impossible. Acknowledgment is also made for the frequent and generous assistance of Mrs. George Goodman, librarian of the DeGolyer Collection in the history of Science and Technology where the bulk of the preparation was done. ___ Generous help and advice in searching manuscript materials was provided by Miss Juliet Wolohan, director of the Historical Manuscripts Division of the New fork State Library, Albany, New fork; Mr. M. D. Smith, manuscripts librarian at the American Philosophical Society Library, Philadelphia, Pennsylvania; and Dr. Kathan Seingold, editor of the Joseph Henry Papers, bmithsonian Institution, Wash­ ington, D.
  • Gold: California State Mineral

    Gold: California State Mineral

    CALIFORNIA GEOLOGICAL SURVEY CALIFORNIA STATE MINERAL The accidental discovery of gold in 1848 at Sutter’s open-pit mining. A technique called heap leaching Mill in Coloma started a bonanza that brought is commonly used to remove finely disseminated California fame and gave it the title of the “Golden gold from low-grade ore. In this process, mounds of State.” The Gold Rush of 1849 and the subsequent crushed ore are placed on an impermeable pad and influx of settlers led to California becoming the 31st sprayed with a dilute cyanide solution. The cyanide state in 1850. solution percolates through the ore and dissolves fine gold particles. The gold is then electrolytically NATURAL OCCURRENCES recovered from solution and poured into ingots. The concentration of gold ore, and the market value Gold is also a byproduct of sand and gravel of gold determine whether a deposit is a mineable production and base metal (copper, lead and zinc) orebody. The highest grade deposits are associated mining. with quartz veins. Gold also occurs as disseminated particles incorporated during magmatic rock GOLD DEPOSITS IN CALIFORNIA formation or during subsequent chemical alteration California’s most important gold deposits have been of the host rock. Primary gold occurrences are found in the Sierra Nevada, Klamath Mountains termed lode deposits. Mineralized rock and gold- and Mojave Desert. Significant deposits have also bearing veins release gold particles during the been developed in the Peninsular and Transverse weathering process. Because of its high specific Ranges and the northern Great Valley. Unmined gravity and resistance to weathering, these sedimen- low-grade deposits occur statewide.