Extrusive and Intrusive Komatiites and Komatiitic Basalts, Peperites, and Ore Genesis at the Dundonald Ni-Cu-(PGE) Deposit, Abitibi Greenstone Belt, Canada
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Geologic Storage Formation Classification: Understanding Its Importance and Impacts on CCS Opportunities in the United States
BEST PRACTICES for: Geologic Storage Formation Classification: Understanding Its Importance and Impacts on CCS Opportunities in the United States First Edition Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed therein do not necessarily state or reflect those of the United States Government or any agency thereof. Cover Photos—Credits for images shown on the cover are noted with the corresponding figures within this document. Geologic Storage Formation Classification: Understanding Its Importance and Impacts on CCS Opportunities in the United States September 2010 National Energy Technology Laboratory www.netl.doe.gov DOE/NETL-2010/1420 Table of Contents Table of Contents 5 Table of Contents Executive Summary ____________________________________________________________________________ 10 1.0 Introduction and Background -
Mantle Peridotite Xenoliths
Earth and Planetary Science Letters 260 (2007) 37–55 www.elsevier.com/locate/epsl Mantle peridotite xenoliths in andesite lava at El Peñon, central Mexican Volcanic Belt: Isotopic and trace element evidence for melting and metasomatism in the mantle wedge beneath an active arc ⁎ Samuel B. Mukasa a, , Dawnika L. Blatter b, Alexandre V. Andronikov a a Department of Geological Sciences, University of Michigan, Ann Arbor, MI 48109-1005, USA b Department of Earth and Planetary Science, University of California, Berkeley, CA 94720, USA Received 6 July 2006; received in revised form 3 May 2007; accepted 7 May 2007 Available online 13 May 2007 Editor: R.W. Carlson Abstract Peridotites in the mantle wedge and components added to them from the subducting slab are thought to be the source of most arc magmas. However, direct sampling of these materials, which provides a glimpse into the upper mantle beneath an active margin, is exceedingly rare. In the few arc localities where found, peridotite xenoliths are usually brought to the surface by basaltic magmas. Remarkably, the hornblende-bearing ultramafic xenoliths and clinopyroxene megaxenocrysts from El Peñon in the central Mexican Volcanic Belt were brought to the surface by a Quaternary high-Mg siliceous andesite, a rock type usually considered too evolved to be a direct product of mantle melting. The xenoliths and megaxenocrysts from El Peñon represent lithospheric mantle affected by significant subduction of oceanic lithosphere since as early as the Permian. Trace element and radiogenic isotope data we report here on these materials suggest a history of depletion by melt extraction, metasomatism involving a fluid phase, and finally, limited reaction between the ultramafic materials and the host andesite, probably during transport. -
Bedrock Geology Glossary from the Roadside Geology of Minnesota, Richard W
Minnesota Bedrock Geology Glossary From the Roadside Geology of Minnesota, Richard W. Ojakangas Sedimentary Rock Types in Minnesota Rocks that formed from the consolidation of loose sediment Conglomerate: A coarse-grained sedimentary rock composed of pebbles, cobbles, or boul- ders set in a fine-grained matrix of silt and sand. Dolostone: A sedimentary rock composed of the mineral dolomite, a calcium magnesium car- bonate. Graywacke: A sedimentary rock made primarily of mud and sand, often deposited by turbidi- ty currents. Iron-formation: A thinly bedded sedimentary rock containing more than 15 percent iron. Limestone: A sedimentary rock composed of calcium carbonate. Mudstone: A sedimentary rock composed of mud. Sandstone: A sedimentary rock made primarily of sand. Shale: A deposit of clay, silt, or mud solidified into more or less a solid rock. Siltstone: A sedimentary rock made primarily of sand. Igneous and Volcanic Rock Types in Minnesota Rocks that solidified from cooling of molten magma Basalt: A black or dark grey volcanic rock that consists mainly of microscopic crystals of pla- gioclase feldspar, pyroxene, and perhaps olivine. Diorite: A plutonic igneous rock intermediate in composition between granite and gabbro. Gabbro: A dark igneous rock consisting mainly of plagioclase and pyroxene in crystals large enough to see with a simple magnifier. Gabbro has the same composition as basalt but contains much larger mineral grains because it cooled at depth over a longer period of time. Granite: An igneous rock composed mostly of orthoclase feldspar and quartz in grains large enough to see without using a magnifier. Most granites also contain mica and amphibole Rhyolite: A felsic (light-colored) volcanic rock, the extrusive equivalent of granite. -
Neuro-Fuzzy Classification of Felsic Lava Geomorphology at Alarcon Rise, Mexico Christina Hefron Maschmeyer University of South Carolina
University of South Carolina Scholar Commons Theses and Dissertations 2016 Neuro-Fuzzy Classification of Felsic Lava Geomorphology at Alarcon Rise, Mexico Christina Hefron Maschmeyer University of South Carolina Follow this and additional works at: https://scholarcommons.sc.edu/etd Part of the Geology Commons Recommended Citation Maschmeyer, C. H.(2016). Neuro-Fuzzy Classification of Felsic Lava Geomorphology at Alarcon Rise, Mexico. (Master's thesis). Retrieved from https://scholarcommons.sc.edu/etd/3566 This Open Access Thesis is brought to you by Scholar Commons. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of Scholar Commons. For more information, please contact [email protected]. NEURO-FUZZY CLASSIFICATION OF FELSIC LAVA GEOMORPHOLOGY AT ALARCON RISE, MEXICO by Christina Hefron Maschmeyer Bachelor of Science College of Charleston, 2014 Bachelor of Arts College of Charleston, 2014 Submitted in Partial Fulfillment of the Requirements For the Degree of Master of Science in Geological Sciences College of Arts and Sciences University of South Carolina 2016 Accepted by: Scott White, Director of Thesis Michael Bizimis, Reader Brian Dreyer, Reader Lacy Ford, Senior Vice Provost and Dean of Graduate Studies © Copyright by Christina Hefron Maschmeyer, 2016 All Rights Reserved. ii DEDICATION This thesis is dedicated to Dr. Jim Carew for making me go to graduate school. iii ACKNOWLEDGEMENTS Data for this study were collected during cruises in 2012 aboard the R/V Zephyr and R/V Western Flyer and during 2015 on the R/V Rachel Carson and R/V Western Flyer from the Monterey Bay Aquarium Research Institute. I want to thank the captains, crews, ROV pilots and science parties for their work during these expeditions. -
Chapter 2 Alaska’S Igneous Rocks
Chapter 2 Alaska’s Igneous Rocks Resources • Alaska Department of Natural Resources, 2010, Division of Geological and Geophysical Surveys, Alaska Geologic Materials Center website, accessed May 27, 2010, at http://www.dggs.dnr.state.ak.us/?link=gmc_overview&menu_link=gmc. • Alaska Resource Education: Alaska Resource Education website, accessed February 22, 2011, at http://www.akresource.org/. • Barton, K.E., Howell, D.G., and Vigil, J.F., 2003, The North America tapestry of time and terrain: U.S. Geological Survey Geologic Investigations Series I-2781, 1 sheet. (Also available at http://pubs.usgs.gov/imap/i2781/.) • Danaher, Hugh, 2006, Mineral identification project website, accessed May 27, 2010, at http://www.fremontica.com/minerals/. • Digital Library for Earth System Education, [n.d.], Find a resource—Bowens reaction series: Digital Library for Earth System Education website, accessed June 10, 2010, at http://www.dlese.org/library/query.do?q=Bowens%20reaction%20series&s=0. • Edwards, L.E., and Pojeta, J., Jr., 1997, Fossils, rocks, and time: U.S. Geological Survey website. (Available at http://pubs.usgs.gov/gip/fossils/contents.html.) • Garden Buildings Direct, 2010, Rocks and minerals: Garden Buildings Direct website, accessed June 4, 2010, at http://www.gardenbuildingsdirect.co.uk/Article/rocks-and- minerals. • Illinois State Museum, 2003, Geology online–GeoGallery: Illinois State Museum Society database, accessed May 27, 2010 at http://geologyonline.museum.state.il.us/geogallery/. • Knecht, Elizebeth, designer, Pearson, R.W., and Hermans, Majorie, eds., 1998, Alaska in maps—A thematic atlas: Alaska Geographic Society, 100 p. Lillie, R.J., 2005, Parks and plates—The geology of our National parks, monuments, and seashores: New York, W.W. -
Geological Investigations in the Bird River Sill, Southeastern Manitoba (Part of NTS 52L5): Geology and Preliminary Geochemical Results by C.A
GS-19 Geological investigations in the Bird River Sill, southeastern Manitoba (part of NTS 52L5): geology and preliminary geochemical results by C.A. Mealin1 Mealin, C.A. 2006: Geological investigations in the Bird River Sill, southeastern Manitoba (part of NTS 52L5): geology and preliminary geochemical results; in Report of Activities 2006, Manitoba Science, Technology, Energy and Mines, Manitoba Geological Survey, p. 214–225. Summary and gravitational differentiation. In 2005, this study was initiated to examine the Bird Theyer (1985) identified unusual River Sill (BRS), a mafic-ultramafic layered intrusion cooling conditions requiring several magma pulses and located in the Bird River greenstone belt in southeastern cast doubt on a single magmatic intrusion theory. Manitoba. The BRS is currently an exploration target In 2005, this study was initiated to examine the for Ni-Cu–platinum group element (PGE) deposits and, controls on Ni-Cu-PGE mineralization and test the single in the past, hosted two Ni-Cu mines (Maskwa West and versus multiple injection hypothesis to establish the Dumbarton mines). relationship between mineralization and the magmatic Nickel-copper mineralization on the western half history. Specific objectives include of the BRS consists primarily of disseminated to blebby • detailed mapping of the Chrome, Page, Peterson pyrrhotite+chalcopyrite and is present in the ultramafic Block and National-Ledin properties (Figure GS-19-1); series of the Chrome and Page properties and the mafic • determination of the sulphur source for the Ni-Cu- series of the Wards property. During this study, several PGE mineralization; new sulphide-bearing localities in both the ultramafic and • delineation of the sill’s sulphur saturation history; mafic units of the sill have been identified. -
Geologic Influences on Apache Trout Habitat in the White Mountains of Arizona
GEOLOGIC INFLUENCES ON APACHE TROUT HABITAT IN THE WHITE MOUNTAINS OF ARIZONA JONATHAN W. LONG, ALVIN L. MEDINA, Rocky Mountain Research Station, U.S. Forest Service, 2500 S. Pine Knoll Dr, Flagstaff, AZ 86001; and AREGAI TECLE, Northern Arizona University, PO Box 15108, Flagstaff, AZ 86011 ABSTRACT Geologic variation has important influences on habitat quality for species of concern, but it can be difficult to evaluate due to subtle variations, complex terminology, and inadequate maps. To better understand habitat of the Apache trout (Onchorhynchus apache or O. gilae apache Miller), a threatened endemic species of the White Mountains of east- central Arizona, we reviewed existing geologic research to prepare composite geologic maps of the region at intermediate and fine scales. We projected these maps onto digital elevation models to visualize combinations of lithology and topog- raphy, or lithotopo types, in three-dimensions. Then we examined habitat studies of the Apache trout to evaluate how intermediate-scale geologic variation could influence habitat quality for the species. Analysis of data from six stream gages in the White Mountains indicates that base flows are sustained better in streams draining Mount Baldy. Felsic parent material and extensive epiclastic deposits account for greater abundance of gravels and boulders in Mount Baldy streams relative to those on adjacent mafic plateaus. Other important factors that are likely to differ between these lithotopo types include temperature, large woody debris, and water chemistry. Habitat analyses and conservation plans that do not account for geologic variation could mislead conservation efforts for the Apache trout by failing to recognize inherent differences in habitat quality and potential. -
Hydrated Peridotite – Basaltic Melt Interaction Part I: Planetary Felsic Crust Formation at Shallow Depth Anastassia Y
Hydrated Peridotite – Basaltic Melt Interaction Part I: Planetary Felsic Crust Formation at Shallow Depth Anastassia Y. BORISOVA1,2*, Nail R. ZAGRTDENOV1, Michael J. TOPLIS3, Wendy A. BOHRSON4, Anne NEDELEC1, Oleg G. SAFONOV2,5,6, Gleb S. POKROVSKI1, Georges CEULENEER1, Ilya N. BINDEMAN7, Oleg E. MELNIK8, Klaus Peter JOCHUM9, Brigitte STOLL9, Ulrike WEIS9, Andrew Y. BYCHKOV2, Andrey A. GURENKO10, Svyatoslav SHCHEKA11, Artem TEREHIN5, Vladimir M. POLUKEEV5, Dmitry A. VARLAMOV5, Kouassi E.A. CHARITEIRO1, Sophie GOUY1, Philippe de PARSEVAL1 1 Géosciences Environnement Toulouse, Université de Toulouse; UPS, CNRS, IRD, Toulouse, France 2 Geological Department, Lomonosov Moscow State University, Vorobievy Gory, 119899, Moscow, Russia 3 Institut de Recherche en Astrophysique et Planétologie (IRAP) UPS, CNRS, Toulouse, France 4 Central Washington University, Department of Geological Sciences, Ellensburg, WA 98926, USA 5 Korzhinskii Institute of Experimental Mineralogy, 142432, Chernogolovka, Moscow region, Russia 6 Department of Geology, University of Johannesburg PO Box 524, Auckland Park, 2006, Johannesburg, South Africa 7 Geological Sciences, University of Oregon, 1275 E 13th street, Eugene, OR, USA 8 Institute of Mechanics, Moscow State University, 1- Michurinskii prosp, 119192, Moscow, Russia 9 Climate Geochemistry Department, Max Planck Institute for Chemistry, P.O. Box 3060, D-55020 Mainz, Germany 10 Centre de Recherches Pétrographiques et Géochimiques, UMR 7358, Université de Lorraine, 54501 Vandœuvre-lès-Nancy, France 11 Bavarian Research -
Depth and Degree of Melting of Komatiites
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 97, NO. B4, PAGES 4521-4540, APRIL 10, 1992 Depth and Degree of Melting of Komatiites CLAUDE HERZBERG Departmentof GeologicalSciences, Rutgers University,New Brunswick,New Jersey Mineral PhysicsInstitute, State Universityof New York, StonyBrook, New York High pressuremelting experimentsßhove ." v .......... new constraintsto be placedon the depthand degreeof partial melting of komatiites. Komatiitesfrom GorgonaIsland were formed by relatively low degreesof pseudoinvariantmelting(< 30 %)involving L + O1 + Opx + Cpx + Gt on the solidusat 40 kbar, about 130 km depth. Munro-typekomatiites were separatedfrom a harzburgiteresidue (L + O1 + Opx) at pressuresthat are poorly constrained,but were probablyaround 50 kbar, about 165 km depth;the degreeof partial melting was <40%. Komatiites from the BarbertonMountain Land were formed by high degrees(-50 %) of pseudoinvariantmelting (L + O1 + Gt + Cpx) of fertile mantleperidotitc in the 80- to 100-kbarrange, about 260- to 330- km depth. Secularvariations in the geochemistryof komatiitescould have formed in response to a reductionin the temperatureand pressureof meltingwith time. The 3.5 Ga Barbertonkomatiites and the 2.7 Ga Munro-typekomatiites could have formedin plumesthat were hotterthan the present-daymantle by 500ø and 30(Y',respectively. When excesstemperatures are this size, melting is deeperand volcanismchanges from basalticto komatiitic. The komatiitesfrom Gorgona Island, which are Mesozoic in age, may be representativeof komatiitesthat are predictedto occur in oceanicplateaus of Cretaceousage throughoutthe Pacific [Storey et al., 1991]. 1. INTRODUCTION range of CaO and A1203contents in the 80- to 160-kbar range. A calibration has been made of the effect of pressure on Komatiites are high MgO volcanic rocks that can be CaO/(CaO + A1203)and MgO in komatiiticliquids formed on roughly explained by high degrees of melting of mantle the solidus, and an examinationhas been made of the effect of peridotitc,typically 50 to 100 % [e.g., Vi.ljoenand Vi.ljoen, FeO. -
The Science Behind Volcanoes
The Science Behind Volcanoes A volcano is an opening, or rupture, in a planet's surface or crust, which allows hot magma, volcanic ash and gases to escape from the magma chamber below the surface. Volcanoes are generally found where tectonic plates are diverging or converging. A mid-oceanic ridge, for example the Mid-Atlantic Ridge, has examples of volcanoes caused by divergent tectonic plates pulling apart; the Pacific Ring of Fire has examples of volcanoes caused by convergent tectonic plates coming together. By contrast, volcanoes are usually not created where two tectonic plates slide past one another. Volcanoes can also form where there is stretching and thinning of the Earth's crust in the interiors of plates, e.g., in the East African Rift, the Wells Gray-Clearwater volcanic field and the Rio Grande Rift in North America. This type of volcanism falls under the umbrella of "Plate hypothesis" volcanism. Volcanism away from plate boundaries has also been explained as mantle plumes. These so- called "hotspots", for example Hawaii, are postulated to arise from upwelling diapirs with magma from the core–mantle boundary, 3,000 km deep in the Earth. Erupting volcanoes can pose many hazards, not only in the immediate vicinity of the eruption. Volcanic ash can be a threat to aircraft, in particular those with jet engines where ash particles can be melted by the high operating temperature. Large eruptions can affect temperature as ash and droplets of sulfuric acid obscure the sun and cool the Earth's lower atmosphere or troposphere; however, they also absorb heat radiated up from the Earth, thereby warming the stratosphere. -
Complex Basalt-Mugearite Sill in Piton Des Neiges Volcano, Reunion
THE AMERICAN MINERALOGIST. VOL. 52, SEPTEMBER-OCTOBER, 1967 COMPLEX BASALT-MUGEARITE SILL IN PITON DES NEIGES VOLCANO, REUNION B. G. J. UetoN, Grant Institute oJ Geology,Uniaersi,ty oJ Ed.inburgh, Edinbwrgh, Scotland, AND W. J. WaoswoRru, Deportmentof Geology,The Un'it;ersity, Manchester,England.. ABsrRAcr An extensive suite of minor intrusions, contempcraneous with the late-stage differenti- ated lavas of Piton des Neiges volcano, occurs within an old agglomeratic complex. An 8-m sill within this suite is strongly difierentiated with a basaltic centre (Thorton Tuttle Index 27.6), residual veins of benmoreite (T. T. Index 75.2), and still more extreme veinlets of quartz trachyte. Although gravitative settling of olivine, augite and ore irz silzr is believed to be responsible for some of the observed variation, the over-all composition of the sill is con- siderably more basic than the mugearite which forms the chilled contacts. It is therefore concluded that considerable magmatic difierentiation must have preceded the emplacement of the sill. This probably took place in a dykeJike magma body with a compositional gra- dient from mugearite at the top to olivine basalt in the lower parts. INrnonucrroN The island of Reunion, in the western Indian Ocean, has the form of a volcanic doublet overlying a great volcanic complex rising from the deep ocean floor. The southeastern component of this doublet is still highly active and erupts relatively undifierentiated, olivine-rich basalts of mildly alkaline or transitional type (Coombs, 1963; Upton and Wads- worth, 1966). The northwestern volcano however has been inactive a sufficient time for erosionalprocesses to have hollowed out amphitheatre- headed valleys up to 2500 meters deep in the volcanic pile. -
Part 629 – Glossary of Landform and Geologic Terms
Title 430 – National Soil Survey Handbook Part 629 – Glossary of Landform and Geologic Terms Subpart A – General Information 629.0 Definition and Purpose This glossary provides the NCSS soil survey program, soil scientists, and natural resource specialists with landform, geologic, and related terms and their definitions to— (1) Improve soil landscape description with a standard, single source landform and geologic glossary. (2) Enhance geomorphic content and clarity of soil map unit descriptions by use of accurate, defined terms. (3) Establish consistent geomorphic term usage in soil science and the National Cooperative Soil Survey (NCSS). (4) Provide standard geomorphic definitions for databases and soil survey technical publications. (5) Train soil scientists and related professionals in soils as landscape and geomorphic entities. 629.1 Responsibilities This glossary serves as the official NCSS reference for landform, geologic, and related terms. The staff of the National Soil Survey Center, located in Lincoln, NE, is responsible for maintaining and updating this glossary. Soil Science Division staff and NCSS participants are encouraged to propose additions and changes to the glossary for use in pedon descriptions, soil map unit descriptions, and soil survey publications. The Glossary of Geology (GG, 2005) serves as a major source for many glossary terms. The American Geologic Institute (AGI) granted the USDA Natural Resources Conservation Service (formerly the Soil Conservation Service) permission (in letters dated September 11, 1985, and September 22, 1993) to use existing definitions. Sources of, and modifications to, original definitions are explained immediately below. 629.2 Definitions A. Reference Codes Sources from which definitions were taken, whole or in part, are identified by a code (e.g., GG) following each definition.