Feldspar Diagenesis in Cambrian Clastic Rocks Of

Total Page:16

File Type:pdf, Size:1020Kb

Feldspar Diagenesis in Cambrian Clastic Rocks Of Feldspar Diagenesis in Cambrian Clastic Rocks of the Southern Ozark Mountains and Reelfoot Rift, Southeastern Missouri and Northeastern Arkansas Implications for Mississippi Valley-Type Ore Genesis U.S. GEOLOGICAL SURVEY BULLETIN 1989-F AVAILABILITY OF BOOKS AND MAPS OF THE U.S. GEOLOGICAL SURVEY Instructions on ordering publications of the U.S. Geological Survey, along with prices of the last offerings, are given in the current-year issues of the monthly catalog "New Publications of the U.S. Geological Survey." Prices of available U.S. Geological Survey publications re­ leased prior to the current year are listed in the most recent annual "Price and Availability List." Publications that may be listed in various U.S. Geological Survey catalogs (see back inside cover) but not listed in the most recent annual "Price and Availability List" may no longer be available. Reports released through the NHS may be obtained by writing to the National Technical Information Service, U.S. Department of Commerce, Springfield, VA 22161; please include NTIS report number with inquiry. Order U.S. Geological Survey publications by mail or over the counter from the offices listed below. BY MAIL OVER THE COUNTER Books Books and Maps Professional Papers, Bulletins, Water-Supply Papers, Tech­ Books and maps of the U.S. Geological Survey are available niques of Water-Resources Investigations, Circulars, publications of over the counter at the following U.S. Geological Survey offices, all general interest (such as leaflets, pamphlets, booklets), single copies of which are authorized agents of the Superintendent of Documents. of Earthquakes & Volcanoes, Preliminary Determination of Epicen­ ters, and some miscellaneous reports, including some of the forego­ ing series that have gone out of print at the Superintendent of ANCHORAGE, Alaska-Rm. 101, 4230 University Dr. Documents, are obtainable by mail from LAKEWOOD, Colorado-Federal Center, Bldg. 810 VS. Geological Survey, Information Services Box 25286, Federal Center MENLO PARK, California-Bldg. 3, Rm. 3128, Denver, CO 80225 345 Middlefield Rd. Subscriptions to periodicals (Earthquakes & Volcanoes and RESTON, Virginia-USGS National Center, Rm. 1C402, Preliminary Determination of Epicenters) can be obtained ONLY 12201 Sunrise Valley Dr. from the SALT LAKE CITY, Utah-Federal Bldg., Rm. 8105, Superintendent of Documents 125 South State St. Government Printing Office Washington, DC 20402 SPOKANE, Washington-U.S. Post Office Bldg., Rm. 135, West 904 Riverside Ave. (Check or money order must be payable to Superintendent of Documents.) WASHINGTON, D.C.-Main Interior Bldg., Rm. 2650, 18th and C Sts., NW. Maps Maps Only For maps, address mail orders to Maps may be purchased over the counter at the following VS. Geological Survey, Information Services U.S. Geological Survey offices: Box 25286, Federal Center Denver, CO 80225 FAIRBANKS, Alaska-New Federal Bldg, 101 Twelfth Ave. Residents of Alaska may order maps from ROLLA, Missouri-1400 Independence Rd. US. Geological Survey, Earth Science Information Center 101 Twelfth Ave., Box 12 STENNIS SPACE CENTER, Mississippi-Bldg. 3101 Fairbanks, AK 99701 Chapter F Feldspar Diagenesis in Cambrian Clastic Rocks of the Southern Ozark Mountains and Reelfoot Rift, Southeastern Missouri and Northeastern Arkansas Implications for Mississippi Valley-Type Ore Genesis By S.F. DIEHL and M.B. GOLDHABER U.S. GEOLOGICAL SURVEY BULLETIN 1989 STRATEGIC AND CRITICAL MINERALS IN THE MIDCONTINENT REGION, UNITED STATES WARREN C. DAY AND DIANE E. LANE, Editors U.S. DEPARTMENT OF THE INTERIOR BRUCE BABBITT, Secretary U.S. GEOLOGICAL SURVEY Gordon P. Eaton, Director Published in the Central Region, Denver, Colo. Manuscript approved for publication March 11,1994. Photocomposition by Gayle M. Dumonceaux. 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. UNITED STATES GOVERNMENT PRINTING OFFICE: 1995 For sale by U.S. Geological Survey, Information Services Box 25286, Federal Center Denver, CO 80225 Library of Congress Cataloging-in-Publication Data Diehl, S. F. Feldspar diagenesis in Cambrian clastic rocks of the southern Ozark Mountains and Reelfoot Rift, southeastern Missouri and northeastern Arkansas: Implications for Mississippi Valley-type ore genesis / by S.F. Diehl and M.B. Goldhaber. p. cm. (U.S. Geological Survey bulletin: 1989) (Strategic and critical minerals in the midcontinent region, United States; ch. F) Includes bibliographical references. Supt. of Docs, no.: 119.3:1989F 1. Diagenesis Missouri. 2. Feldspar Missouri. 3. Geology, Stratigraphic Cambrian. 4. Lamotte Sandstone (Mo.) I. Goldhaber, Martin B. II. Title. III. Series. IV. Series: Strategic and critical minerals in the midcontinent region, United States: ch. F. QE75.B9 no. 1989-F [QE571] 557.3s dc20 94-12432 [552'.03] CIP CONTENTS Abstract Fl Introduction Fl Regional structure F2 Description of the Lamotte Sandstone and time-equivalent rocks in the Reelfoot Rift F3 Methods and materials F3 Petrographic descriptions of samples from core fence A-A' F4 Reelfoot Rift F4 Dow Chemical No. 1 Wilson drill hole F5 Dow Chemical No. 1 Garrigan drill hole F5 Strake Petroleum No. 1 Russell drill hole F6 Drill hole BT1 F7 Indian Creek Subdistrict Goose Creek Mine F7 Petrographic descriptions of samples from core fence B-B' F9 Drill hole 63W72 F9 Drill hole 63W5 F9 Results of petrographic studies of core from other drill holes F10 Discussion F10 Timing of feldspar precipitation relative to Mississippi Valley-type ore genesis Fll Contrasts between Reelfoot Rift and platform settings hi feldspar diagenesis F13 Formation and dissolution of potassium hi the Lamotte Sandstone outside the Reelfoot Rift F14 Additional evidence for a link between the Reelfoot Rift and lead-belt mineralization F15 The anomalous nature of the Strake well samples F15 Summary F15 References cited F16 FIGURES Fl. Map showing location of drill holes, major structural terrains, and ore districts in the study area F2 F2-F6. Photomicrographs showing: F2. Deuital microcline grain and partially dissolved overgrowth, Dow Chemi­ cal No. 1 Wilson drill hole F5 F3. Plagioclase grain and albite overgrowths, and authigenic albite enclosing remnants of carbonate minerals, Dow Chemical No. 1 Garrigan drill hole F6 F4. Inclusion-rich authigenic potassium feldspar overgrowths on deuital feld­ spar grains, Strake Petroleum No. 1 Russell drill hole F6 F5. Etched rhombic potassium feldspar overgrowths on a hematitic feldspar grain and an orthoclase grain and its overgrowth, drill hole BT1 F7 F6. Galena cement that partially encloses a detrital potassium feldspar grain and its overgrowth, and galena cement that invaded dissolution voids hi a partially dissolved potassium feldspar grain, Goose Creek Mine F8 F7. Scanning-electron photomicrographs of samples from Goose Creek Mine, in Contents III Indian Geek subdistrict F8 F8. Diagram showing mineral paragenetic sequence in Indian Creek subdistrict F9 F9. Photomicrograph showing two generations of potassium feldspar overgrowths on a microcline grain F9 F10. Photomicrograph of a detrital feldspar grain and two generations of potassium feldspar overgrowths that have undergone dissolution F10 Fl 1. Map showing abundance of potassium feldspar cement and the amount of dissolution of the cement plotted at the drill hole locations Fl 1 F12. Photomicrograph showing that different generations of potassium feldspar over­ growths may be differentially affected by dissolution F12 Fl 3. Plot of point-count data for albite and potassium feldspar from shallowly buried Lamotte Sandstone and deeply buried siliciclastic rocks versus depth F13 F14. Potassium feldspar stability diagram at 150°C. F14 TABLES Fl. Percent of bulk rock constituents in selected thin sections F4 F2. Estimation of composition of ore-forming fluid hi the study area F14 IV Contents STRATEGIC AND CRITICAL MINERALS IN THE MIDCONTINENT REGION, UNITED STATES Feldspar Diagenesis in Cambrian Clastic Rocks of the Southern Ozark Mountains and Reelfoot Rift, Southeastern Missouri and Northeastern Arkansas Implications for Mississippi Valley-Type Ore Genesis ByS.F. Diehl and M.B. Goldhaber Abstract potassium feldspar are significantly different in shallowly buried Lamotte Sandstone than in time-equivalent deeply The Upper Cambrian Lamotte Sandstone is consid­ buried sedimentary rocks in the Reelfoot Rift. Potassium ered to have been a major aquifer for warm basinal brines feldspar grains in the Reelfoot Rift samples show increas­ that formed the Mississippi Valley-type (MVT) mineral ingly greater alteration to albite with depth, and albitization deposits in Missouri. Petrographic studies of authigenic is an important process that enriches pore fluids in K+. potassium feldspar in the Lamotte Sandstone constrain the geochemistry of the ore-forming fluids. Authigenic potas­ sium feldspar is important because (1) it has been dated as INTRODUCTION late Paleozoic, which broadly coincides with the inferred time of ore genesis, (2) previous petrographic studies con­ The Upper Cambrian Lamotte Sandstone is of inter­ strain the relative time authigenic feldspar dissolved with est as a major aquifer that transported ore-bearing fluids respect to deposition of the lead-zinc ore, and (3) MVT for the Mississippi Valley-type (MVT) deposits of the ore fluids are typically anomalously rich in K+. southern midcontinent of the United States. We undertook a regional study of the Lamotte Sandstone to characterize
Recommended publications
  • Study of Geologic Structures and Rock Properties in the Standard Mine Vicinity, Gunnison County, Colorado
    Prepared in cooperation with the U.S. Environmental Protection Agency Characterization of Geologic Structures and Host Rock Properties Relevant to the Hydrogeology of the Standard Mine in Elk Basin, Gunnison County, Colorado Open-File Report 2010–1008 U.S. Department of the Interior U.S. Geological Survey Front cover: Photograph of upper Elk Basin looking east from the cirque ridge. Characterization of Geologic Structures and Host Rock Properties Relevant to the Hydrogeology of the Standard Mine in Elk Basin, Gunnison County, Colorado By Jonathan Saul Caine, Andrew H. Manning, Byron R. Berger, Yannick Kremer, Mario A. Guzman, Dennis D. Eberl, and Kathryn Schuller Prepared in cooperation with the U.S. Environmental Protection Agency Open-File Report 2010–1008 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior KEN SALAZAR, Secretary U.S. Geological Survey Marcia K. McNutt, Director U.S. Geological Survey, Reston, Virginia: 2010 For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment, visit http://www.usgs.gov or call 1-888-ASK-USGS For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprod To order this and other USGS information products, visit http://store.usgs.gov Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this report.
    [Show full text]
  • Structure and Emplacement of Cretaceous Plutons in Northwest Yosemite National Park, California
    San Jose State University SJSU ScholarWorks Master's Theses Master's Theses and Graduate Research Spring 2014 Structure and Emplacement of Cretaceous Plutons in Northwest Yosemite National Park, California Ashley Van Dyne San Jose State University Follow this and additional works at: https://scholarworks.sjsu.edu/etd_theses Recommended Citation Van Dyne, Ashley, "Structure and Emplacement of Cretaceous Plutons in Northwest Yosemite National Park, California" (2014). Master's Theses. 4442. DOI: https://doi.org/10.31979/etd.akfj-5ha8 https://scholarworks.sjsu.edu/etd_theses/4442 This Thesis is brought to you for free and open access by the Master's Theses and Graduate Research at SJSU ScholarWorks. It has been accepted for inclusion in Master's Theses by an authorized administrator of SJSU ScholarWorks. For more information, please contact [email protected]. STRUCTURE AND EMPLACEMENT OF CRETACEOUS PLUTONS, NORTHWEST YOSEMITE NATIONAL PARK, CALIFORNIA A Thesis Presented to The Faculty of the Department of Geology San José State University In partial Fulfillment of the Requirements for the Degree Master of Science by Ashley L. Van Dyne May 2014 © 2014 Ashley L. Van Dyne ALL RIGHTS RESERVED The Designated Thesis Committee Approves the Thesis Titled STRUCTURE AND EMPLACEMENT OF CRETACEOUS PLUTONS, NORTHWEST YOSEMITE NATIONAL PARK, CALIFORNIA by Ashley L. Van Dyne APPROVED FOR THE DEPARTMENT OF GEOLOGY SAN JOSE STATE UNIVERSITY April 2014 Dr. Robert Miller Department of Geology Dr. Jonathan Miller Department of Geology Dr. Ellen Metzger Department of Geology ABSTRACT STRUCTURE AND EMPLACEMENT OF CRETACEOUS PLUTONS, NORTHWEST YOSEMITE NATIONAL PARK, CALIFORNIA by Ashley L. Van Dyne The ~103-98 Ma Yosemite Valley Intrusive Suite, younger Granodiorite North of Tuolumne Peak, and ~97 Ma Yosemite Creek Granodiorite intrude plutonic and metasedimentary host rocks of the central Sierra Nevada batholith.
    [Show full text]
  • An Investigation Into the UV Fluorescence of Feldspar Group
    An Investigation into UV Fluorescence in Feldspar Group Minerals Natasha Morrison Submitted in Partial Fulfillment of the Requirement for the Degree of Honours Bachelor of Science, Department of Earth Sciences At Dalhousie University Halifax, Nova Scotia March 17th, 2013 Submitted to: Dr. Richard Cox Dr. Martin Gibling 1 Distribution License DalSpace requires agreement to this non-exclusive distribution license before your item can appear on DalSpace. NON-EXCLUSIVE DISTRIBUTION LICENSE You (the author(s) or copyright owner) grant to Dalhousie University the non-exclusive right to reproduce and distribute your submission worldwide in any medium. You agree that Dalhousie University may, without changing the content, reformat the submission for the purpose of preservation. You also agree that Dalhousie University may keep more than one copy of this submission for purposes of security, back-up and preservation. You agree that the submission is your original work, and that you have the right to grant the rights contained in this license. You also agree that your submission does not, to the best of your knowledge, infringe upon anyone's copyright. If the submission contains material for which you do not hold copyright, you agree that you have obtained the unrestricted permission of the copyright owner to grant Dalhousie University the rights required by this license, and that such third-party owned material is clearly identified and acknowledged within the text or content of the submission. If the submission is based upon work that has been sponsored or supported by an agency or organization other than Dalhousie University, you assert that you have fulfilled any right of review or other obligations required by such contract or agreement.
    [Show full text]
  • A Survey of Ice Nucleating Properties Across the Feldspar Group Of
    Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-136, 2016 Manuscript under review for journal Atmos. Chem. Phys. Published: 19 February 2016 c Author(s) 2016. CC-BY 3.0 License. 1 Not all feldspar is equal: a survey of ice nucleating 2 properties across the feldspar group of minerals 3 4 Alexander D. Harrison1ǂ, Thomas F. Whale1ǂ*, Michael A. Carpenter2, Mark A. 1 1 1 1 5 Holden , Lesley Neve , Daniel O’Sullivan , Jesus Vergara Temprado , Benjamin 6 J. Murray1* 7 1School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK 8 2 Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 9 3EQ, UK 10 Correspondence to: T. F. Whale ([email protected]) and B. J. Murray 11 ([email protected]) 12 13 ǂ Both authors contributed equally to the paper 14 15 Abstract 16 Mineral dust particles from wind-blown soils are known to act as effective ice nucleating 17 particles in the atmosphere and are thought to play an important role in the glaciation of 18 mixed phase clouds. Recent work suggests that feldspars are the most efficient nucleators of 19 the minerals commonly present in atmospheric mineral dust. However, the feldspar group of 20 minerals is complex, encompassing a range of chemical compositions and crystal structures. 21 To further investigate the ice-nucleating properties of the feldspar group we measured the ice 22 nucleation activities of 15 well-characterised feldspar samples. We show that alkali feldspars, 23 in particular the potassium feldspars, generally nucleate ice more efficiently than feldspars 24 containing significant amounts of calcium in the plagioclase series.
    [Show full text]
  • Production, Reserves, and Processing of Feldspar and Feldspathoid Rocks in the Czech Republic from 2005 to 2019—An Overview
    minerals Article Production, Reserves, and Processing of Feldspar and Feldspathoid Rocks in the Czech Republic from 2005 to 2019—An Overview Jan Zahradník 1,2 , Jakub Jirásek 3,*, Jaromír Starý 4 and Martin Sivek 2 1 LB MINERALS, s.r.o., Tovární 431, 330 12 Horní Bˇríza, Czech Republic; [email protected] 2 Department of Geological Engineering, Faculty of Mining and Geology, Vysoká Škola Báˇnská-Technical University of Ostrava, 17. listopadu 15/2172, 708 00 Ostrava-Poruba, Czech Republic; [email protected] 3 Department of Geology, Faculty of Science, Palacký University Olomouc, 17. listopadu 1192/12, 771 46 Olomouc, Czech Republic 4 Czech Geological Survey, Klárov 3, 118 21 Praha, Czech Republic; [email protected] * Correspondence: [email protected] Received: 5 July 2020; Accepted: 10 August 2020; Published: 17 August 2020 Abstract: This paper aims to characterize and interpret the trends in reserves, resources, and mine production of feldspar and feldspathoid rocks during 2005–2019 in the Czech Republic. With over 101 Mt of total resources and 22 Mt of reserves, feldspar belongs to the crucial industrial minerals of the Czech Republic. With annual outputs of approximately 400–450 kt of feldspars and 20–35 kt of feldspathoid rocks (nepheline syenite), the Czech Republic ranks among the top European and world feldspar producers. Most of the production comes from leucocratic granitoid rocks (key active deposit: Krásno-Vysoký Kámen), followed by sedimentary rocks (key active deposit: Halámky), and granitic pegmatites (key active deposit: Luženiˇcky).Nepheline syenite is mined at a single deposit. All deposits are extracted from open pits (quarries).
    [Show full text]
  • Formation of the Yosemite Creek Granodiorite: a Field and Geochemical Study
    Formation of the Yosemite Creek Granodiorite: a field and geochemical study 14 12 10 8 6 4 15 2 14 phonolite0 13 40 50 60 70 80 12 tephri- trachyte (q<20%) phonolite 11 trachydacite (q>20%) foidite 10 phono- tephrite trachy- 9 andesite rhyolite 8 tephrite ba sa ltic (ol<10%) trachy- 7 andesite basanite trachy- 6 (ol>10%) basalt 5 4 dacite 3 asalt andesite b ba sa ltic 2 picro- andesite basalt 1 0 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71 73 75 77 1000 syn-COLG WPG 100 10 VAG 250 1 200 1 10 100 1000 150 100 50 0 0 500 1000 1500 2000 by Erik Bliekendaal Master of Science Thesis Solid Earth Vrije Universiteit Amsterdam 2012 [..] Preface My personal interests in geology developed towards the debate of crust-mantle differentiation during my master. The processes involved in crust-mantle differentiation makes the Earth as it is nowadays. The scale of this phenomena exceed all human proportions with a time-scale that spans the complete history of Earth and will continue far into the future. Length and depth scales of the crust-mantle processes are immense with respect to human proportions. I feel it to be a honour to work with and attribute to such a important and interesting subject. The scientific debate is firm and spreads over a numerous geological disciplines. In my opinion the most interesting of these disciplines are the petrology and geochemistry. Especially the debate with respect to these disciplines is heated and firm due to new geochemical analytical techniques.
    [Show full text]
  • SELECTIVE SEPARATION of Na- and K-FELDSPAR from WEATHERED GRANITES by FLOTATION in HF MEDIUM
    Original papers SELECTIVE SEPARATION OF Na- AND K-FELDSPAR FROM WEATHERED GRANITES BY FLOTATION IN HF MEDIUM CENGIZ DEMIR Karadeniz Technical University, Mining Engineering Department, Trabzon, Turkey E-mail: [email protected] Submitted October 9, 2009 ; accepted January 21, 2010 Keywords: Feldspar, Selective separation, Weathered granites, Flotation, Monovalent salts Granite and granodiorite deposits are widely scattered throughout in Eastern Black Sea region of Turkey. These granitic bodies also contain considerable amounts of quartz, Na-feldspar, K-feldspar, mica and other color-imparting ferruginous impurities. Average chemical composition of these rocks are SiO2 = 65.00 ±5.60; K2O = 3.05 ±1.35; Na2O = 3.50 ±1.47 %. Modally, these rocks contain 21.5 ±5.2 quartz; 19.3 ±4.8 K-feldspar and 48.3 ±10.2 % plagioclase. Although the chemical composition of these run-of-mine granite masses cannot meet the specifications required for the glass and ceramic industry, application of some mineral processing methods may recover quartz, Na-feldspar and K-feldspar as separate products. This study deals with the selective separation of sodium feldspar from potassium feldspar from weathered granite using cationic flotation technique (HF + amine) in the presence of NaCl. The most striking result in this experimental study is the depressive effect of NaCl on Na-feldspar. NaCl addition controls amine adsorption on sodium feldspar through adsorption of Na+ ions onto mineral surfaces. The use of NaCl in flotation was found to increase the K-feldspar grade in the concentrate. This study clearly demonstrates that an effective separation of sodium feldspar from potassium feldspar from a weathered granite can be achieved by cationic flotation in HF medium using NaCl as a depressant.
    [Show full text]
  • Geological Interpretive Trail City of Rocks National Reserve
    Geological Interpretive Trail City of Rocks National Reserve A self‐guided journey to discovering secrets in the rocks at City of Rocks City of Rocks National Reserve is a partnership between the National Park Service and the Idaho Department of Parks and Recreation Geological Interpretive Trail City of Rocks National Reserve A self‐guided journey to discovering A self‐guided journey to discovering the secrets in the rocks of City of Rocks Prepared by Idaho Department of Parks and Recreation and the National Park Service City of Rocks National Reserve PO Box 169 Almo, Idaho 83312 http://parksandrecreation.idaho.gov www.nps.gov/ciro January 2012 Contents What’s in store before you explore? There are twelve interpretive stations along the 0.6 mile trail. The trail rises 160 feet in elevation, makes a loop at the end, and retraces much of the same route for a total of 1.2 miles. Trail Map 3 Introduction 4 Green Creek Complex 5 Almo Pluton 6 Where Granites Meet 7 Geologic Map of Trail Vicinity 8 Overlook: Anticlines, Hogbacks, Upland Basins 9 Physiography of City of Rocks and Castle Rocks 10 Stop 1 Granitic Weathering 11 Stop 2 Panholes 12 Stop 3 Tafoni 13 Stop 4 Joints 14 Geologic Map of City of Rocks 15 Stop 5 Panholes 17 Stop 6 Intrusive Contact 18 Stop 7 Xenolith/Contact 19 Stop 8 Green Creek Window 20 Stop 9 Boulders 21 Stop 10 Joints 22 Stop 11 Pickelhaube 23 Stop 12 Pinnacles 24 Other Points of Geologic Interest 25 Glossary (words underlined) 28 For Further Study 29 Credits 29 Quiz 30 2 3 Introduction City of Rocks National Reserve is part of the Basin and Range geologic province.
    [Show full text]
  • Episodic Fluid Flow in an Active Fault
    Episodic fluid flow in an active fault Sarah Louis1,3, Elco Luijendijk1*, Istvan Dunkl1, and Mark Person2 1University of Göttingen, Goldschmidtstrasse 3, 37077, Göttingen, Germany 2New Mexico Institute of Mining & Technology, 810 Leroy Place, MSEC 248, Socorro NM 87801 USA. 3RWTH Aachen University, Wüllnerstraße 2, 52062 Aachen, Germany *Corresponding author, [email protected] ABSTRACT We present a 250 ky record of episodic fluid flow along the Malpais fault which hosts the Beowawe hydrothermal system, Nevada, USA. Samples show partial resetting of the apatite (U-Th)/He thermochronometer in a 40 m wide zone around the Malpais fault. Numerical models indicate that, using current fluid temperatures and discharge rates, fluid flow events lasting 2000 years or more would lead to fully reset samples. Episodic fluid pulses lasting 1000 years resulted in partially reset samples, with ~36 individual fluid pulses required to match the data. Episodic fluid flow is also supported by an overturned geothermal gradient in a borehole that crosses the fault, and by breaks in stable isotope trends in hydrothermal sinter deposits that coincide with two independently dated earthquakes in the last 20 ky. This suggests a system where fluid flow is triggered by repeated seismic activity and seals itself over ~1000 years due to formation of clay minerals and silicates in the fault damage zone. Hydrothermal activity is younger than the 6-10 Ma age of the fault. This suggests that the onset of deep (~5 km) fluid flow was initiated only after a large part of the total of 230 m offset took place. INTRODUCTION Fault hosted transient fluid flow and hydrothermal activity plays an important role in a wide range of geologic processes, including metalogenesis (Weis et al., 2012), oil migration (Boles et al., 2004), fault mechanics and metamorphism (Magee and Zoback, 1993).
    [Show full text]
  • Evolution of Magmatic and Subsolidus AFM Mineral Assemblages In
    American Mineralogist, Volume 77, pages 821-833, 1992 Evolution of magmatic and subsolidusAFM mineral assemblagesin granitoid rocks: Biotite, muscovite,and garnet in the Cuffytown Creek pluton, South Carolina J. Ar.nx.qxrnn Spnnn Department of Marine, Earth, and Atmospheric Sciences,Box 8208, North Carolina State University, Raleigh,North Carolina27695-8208, U.S.A. SusaN W. Bncxnn l0l YeonasCircle SE,Vienna, Virginia 22180,U.S.A. Ansrnlcr The Cufttown Creek pluton is a leucocratic alkali feldspar granite with (F + Mn)-rich biotite, muscovite, garnet, and fluorite as varietal minerals. Bt + Ms is preserved as inclusion assemblagesin quartz; Bt + Ms + Grt and Ms + Grt are matrix assemblages. The inclusion assemblagesare interpreted as early magmatic, and the matrix assemblages as late magmatic with superimposedsubsolidus partial reequilibration. In sequence,the AFMMn crystallization reactions are liquid : Bt, liquid : Bt + Ms, liquid + Bt : Ms * Grt, and liquid : Grt + Ms. Inclusion biotite showsFeMg-, and Mn(Fe,Mg)-' exchanges, which may reflect both changein melt composition and cooling along an,fo, buffer. Inclu- sions of white mica are nearly end-member muscovite. Evolution from inclusion to matrix mica compositions shows narrowing of the compositional gap between the dioctahedral and trioctahedral micas, as well as OHF-, and MnMg-, exchangesin the biotite and (Fe2*,Mg,Mn)Sil6lAl'lolAl-' (celadonite),NaIL', OHF-r, and Ti enrichmentin the white micas. Garnets are spessartine-almandine. The liquid line of descentindicates that the melt becameincreasingly rich in Fel(Fe + Mg) and Mn/(Fe + Mn) with decreasingtemperatures, but each at differing rates at dif- fering stagesduring crystallization. Peraluminosity of the melt increasedrapidly at first, then decreasedslightly before increasing at a much slower rate.
    [Show full text]
  • MICROCLINE in Pegmatite (Poindexter Et Al., 1939)
    Dickinson County: 1. Near Foster City: In pegmatite (Poindexter et al., 1939). 2. Near Felch: MICROCLINE In pegmatite (Poindexter et al., 1939). 3. KAlSi3O8 Metronite quarry, 4 km east-northeast of Felch: Found in an aplite-pegmatite dike cutting marble (Heinrich, 1962b). 4. East of Randville, approx- imately a kilometer east of Groveland mine: As graphic granite adjacent to the quartz core of a pegmatite (Pratt, 1954). 5. Pegmatite quarry, SE ¼ section 19, T42N, R29W: Perthitic pink microcline in a post-Animikie pegmatite occurs with quartz, albite, muscovite, biotite, beryl, ferrocolumbite, tourmaline, and garnet (James et al., 1961). 6. In a pegmatite dike, “6.4 km northeast of Randville near Tom Kings Creek, a tributary of the West Branch, Sturgeon River” (Hawke, 1976). 7. Road cut on Highway 69, on west end of the village of Felch: Small crystals of pale, orange-pink “adularia” line cavities in brecciated ferruginous sandstone. Gogebic County: 1. Near Lake Gogebic: In pegmatite (Poindexter et al., 1939). 2. Section 2, Figure 102: Microcline (variety “adularia”) crystals T46N, R41W: Pink crystals 12 to 15 cm long and coating wire copper from the Osceola mine, Calumet, sometimes as large as 35 cm are found (Allen, Houghton County. 2 x 5 cm. A. E. Seaman Mineral 1920). 3. Peterson mine, between Ironwood and Museum specimen No. JTR 957, Jeffrey Scovil Bessemer: Pinkish twinned crystals of “adularia” photograph. up to 3 mm occur in cavities in soft hematite ore. Gratiot County: Near Ithaca, T10N, R2W in A low-temperature, triclinic potassium feldspar Michigan Basin Deep Drill Hole in the lower commonly found in granitic rocks.
    [Show full text]
  • Geology, Ground Water Chemistry, and Hydrogeology of the Murphy Area, Josephine County, Oregon
    AN ABSTRACT OF THE THESIS OF Gregory Stebbins Mack for the degree of Master of Science in Geology presented on 3 June 1982 Title: Geology, Ground Water Chemistry, and Hydrogeology of the Murphy Area, Josephine County, Oregon Redacted- for Privacy Abstract approved: J. Dasch The Grants Pass Batholith of Cretaceous age has intrudedthe Triassic Applegate Group and metasedimentary rocks of the Jurassic Galice Formation in the Murphy area of Josephine County,southwest Oregon. The Applegate Group, mafic volcanic and sedimentary rock, has been partially (nonequilibrium) metamorphosedunder greenschist facies conditions. The batholith, a hornblende-biotite granodi- orite, has produced a contact aureole (hornblende-hornfelsfacies) in the country rocks. Electrical conductance (EC), pH, temperature, and HCO3 were measured on 43 samples of well water and ApplegateRiver water in + ++ _ - the field. Analyses forNa+, K+, Mg, Ca , Cl, F ,SO4, total Fe, and SiO (aq) were performed in the laboratory. Two water types 2 based on EC are apparent. A low EC type (< 500 ffIho /cm @ 25°C) is characteristic of HCOwaters; high EC is associated with Clwaters. 3 Grus from the weathered pluton formssatisfactory aquifers with low EC. Applegate Group rocks form a clay-richaquifer containing both high and low EC water. Wells located within the contact aureolein the Galice Formation yield high EC waters. Low EC waters are associatedwith areas of high recharge equiva- lent to the "Local" zone, the shallowest zoneof Toth's (1963) model. Water quality enigmatically is characterized also by a molar Mg/Ca ratio of unity. High EC waters are associated with the emergence of deeper water along hydrogeologic boundaries.
    [Show full text]