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Editorial for Special Issue “Ore Genesis and Metamorphism: Geochemistry, Mineralogy, and Isotopes”
minerals Editorial Editorial for Special Issue “Ore Genesis and Metamorphism: Geochemistry, Mineralogy, and Isotopes” Pavel A. Serov Geological Institute of the Kola Science Centre, Russian Academy of Sciences, 184209 Apatity, Russia; [email protected] Magmatism, ore genesis and metamorphism are commonly associated processes that define fundamental features of the Earth’s crustal evolution from the earliest Precambrian to Phanerozoic. Basically, the need and importance of studying the role of metamorphic processes in formation and transformation of deposits is of great value when discussing the origin of deposits confined to varied geological settings. In synthesis, the signatures imprinted by metamorphic episodes during the evolution largely indicate complicated and multistage patterns of ore-forming processes, as well as the polygenic nature of the mineralization generated by magmatic, postmagmatic, and metamorphic processes. Rapid industrialization and expanding demand for various types of mineral raw ma- terials require increasing rates of mining operations. The current Special Issue is dedicated to the latest achievements in geochemistry, mineralogy, and geochronology of ore and metamorphic complexes, their interrelation, and the potential for further prospecting. The issue contains six practical and theoretical studies that provide for a better understanding of the age and nature of metamorphic and metasomatic transformations, as well as their contribution to mineralization in various geological complexes. The first article, by Jiang et al. [1], reports results of the first mineralogical–geochemical Citation: Serov, P.A. Editorial for studies of gem-quality nephrite from the major Yinggelike deposit (Xinjiang, NW China). Special Issue “Ore Genesis and The authors used a set of advanced analytical techniques, that is, electron probe microanaly- Metamorphism: Geochemistry, sis, X-ray fluorescence (XRF) spectrometry, inductively coupled plasma mass spectrometry Mineralogy, and Isotopes”. -
Washington Division of Geology and Earth Resources Open File Report 86-2, 34 P
COAL MATURATION AND THE NATURAL GAS POTENTIAL OF WESTERN AND CENTRAL WASHINGTON By TIMOTHY J. WALSH and WILLIAMS. LINGLEY, JR. WASHINGTON DIVISION OF GEOLOGY AND EARTH RESOURCES OPEN FILE REPORT 91-2 MARCH 1991 This report has not been edited or reviewed for conformity with Division of Geology and Earth Resources standards and nomenclature. ''llailal WASHINGTONNatural STATE Resources DEPARTMENT OF Brian Boyle ~ Comm1SSioner ol Public Lands Art Stearns Supervisor Division of Geology and Earth Resources Raymond Lasmanis. State Geologist CONTENTS Page Abstract ...................................................... 1 Introduction 1 Tertiary stratigraphy .............................................. 3 Structure as determined from mine maps ................................. 8 Thermal maturation as determined from coal data . 8 Timing of thermal maturation . 16 Mechanisms of heat flow . 17 Exploration significance ............................................ 17 Conclusions 19 References cited . 20 ILLUSTRATIONS Figure 1: Map showing distribution of Ulatisian and Narizian fluvial and deltaic rocks in western and central Washington . 2 Figure 2: Plot of porosity versus depth, selected wells, Puget and Columbia Basins 4 Figure 3: Correlation chart of Tertiary rocks and sediments of western and central Washington . 5 Figure 4: Isopach of Ulatisian and Narizian surface-accumulated rocks in western and central Washington . 7 Figure 5: Isorank contours plotted on structure contours, Wingate seam, Wilkeson-Carbonado coalfield, Pierce County . 9 Figure -
Volcanism and Igneous Intrusion
PNL-2882 UC-70 3 3679 00053 2145 .. ' Assessment of Effectiveness of Geologic Isolation Systems DISRUPTIVE EVENT ANALYSIS: VOLCANISM AND IGNEOUS INTRUSION B. M. Crowe Los Alamos Scientific. Laboratory August 1980 Prepared for the Office of Nuclear Waste Isolation under its Contract with the U.S. Department of Energy Pacific Northwest Laboratory Richland, Washington 99352 PREFACE Associated with commercial nuclear power production in the United States is the generation of potentially hazardous radioactive waste products. The Department of Energy (DOE), through the National Waste Terminal Storage (NWTS) Program and the Office of Nuclear Waste Isolation (ONWI), is seeking to develop nuclear waste isolation systems in geologic formations. These underground waste isolation systems will preclude contact with the biosphere of waste radionuclides in concentrations which are sufficient to cause deleterious impact on humans or their environments. Comprehensive analyses'of specific isolation systems are needed to assess the post-closure expectations of the systems. The Assessment of Effectiveness of Geologic Isolation Systems (AEGIS) .' Program has been established for developing the capability of making those analys;s! Among the analysis'required for the system evaluation is the detailed assessment of the post-closure performance of nuclear waste repositories in geologic formations. This assessment is concerned with aspects of the nuclear program which previously have not been addressed. The nature of the isolation systems (e.g., involving breach scenarios and transport through the geosphere) and the great length of time for which the wastes must be controlled dictate the development, demonstration, and application of novel assessment capabili ties. The assessment methodology must be thorough, flexible, objective, and scientifically defensible. -
06Metamorphs.Pdf
Clicker • The transformation of one rock into another by solid-state Metamorphism and recrystallization is known as Metamorphic Rocks – a) Sedimentation – b) Metamorphism – c) Melting – d) Metasomatism – e) Hydrothermal alteration Metamorphism • Metamorphism is the solid- state transformation of pre- existing rock into texturally or mineralogically distinct new rock as the result of high temperature, high pressure, or both. Diamond is Metamorphic Metamorphism • The mineralogy of a metamorphic rock changes with temperature and pressure. • In general, the highest temperature mineral assemblage is preserved. • It is possible to infer the highest P- T conditions from the mineralogy. 1 Metamorphic Environments Metamorphic Environments • Regional metamorphism • Where do you find metamorphic involves the burial and rocks? metamorphism of entire regions • In the mountains and in continental (hundreds of km2) shield areas. • Contact metamorphism results from local heating adjacent to • Why? igneous intrusions. (several meters) • Because elsewhere they are covered by sediments. Metamorphic Environments Regional Metamorphism • Because the tectonic forces required to bury, metamorphose, and re- exhume entire regions are slow, • most regionally metamorphosed terranes are old (> 500 MY), and • most Precambrian (> 500 MY) terranes are metamorphosed. Regional Metamorphism Regional Metamorphism • Regional metamorphism is typically • Regional metamorphism is typically isochemical (composition of rock isochemical (composition of rock does not change), although water does not change), although water may be lost. may be lost. • Metasomatism is a term for non- • Metasomatism is a term for non- isochemical metamorphism. isochemical metamorphism. • Contact metamorphism is typically • Contact metamorphism is typically metasomatic. metasomatic. 2 Effect of Increasing Conditions of Metamorphism Temperature • Changing the mineralogy of a sediment requires temperature > • Increases the atomic vibrations 300ºC and pressures > 2000 • Decreases the density (thermal atmospheres (~6 km deep). -
OCR Document
AN INTRODUCTORY PROSPECTING MANUAL K N A O S I A T B N A O S N I I T K A F R Prepared by: J. R. Parker (Staff Geologist, Red Lake Resident Geologist Office, Ministry of Northern Development and Mines) Revised in 2004 and 2007 by: D. P. Parker and B. V. D'Silva (D'Silva Parker Associates) Discover Prospecting July 2007 Original Acknowledgments The author would like to thank K.G. Fenwick, Manager, Field Services Section (Northwest) and M.J. Lavigne, Resident Geologist, Thunder Bay, for initiating this prospecting manual project. Thanks also to the members of the Prospecting Manual Advisory Committee: P. Sangster, Staff Geologist, Timmins; M. Smyk, Staff Geologist, Schreiber-Hemlo; M. Garland, Regional Minerals Specialist, Thunder Bay; P. Hinz, Industrial Minerals Geologist, Thunder Bay; E. Freeman, Communications Project Officer, Toronto; R. Spooner, Mining Recorder, Red Lake; R. Keevil, Acting Staff Geologist, Dorset; and T. Saunders, President, N.W. Ontario Prospector's Association, Thunder Bay for their comments, input and advice. The author also thanks R. Spooner, Mining Recorder, Red Lake, for writing the text on the Mining Act in the "Acquiring Mining Lands" section of this manual. Thanks to B. Thompson, Regional Information Officer, Information and Media Section, Thunder Bay, for assistance in the preparation of slides and his advice on the presentation of the manual. Thanks also to B.T. Atkinson, Resident Geologist, Red Lake; H. Brown, Acting Staff Geologist, Red Lake; M. Garland, Regional Minerals Specialist, Thunder Bay; and M. Smyk, Staff Geologist, Schreiber-Hemlo for editing the manuscript of the manual. -
Metasomatic Alteration Associated with Regional Metamorphism: an Example from the Willyama Supergroup, South Australia
Lithos 54Ž. 2000 33±62 www.elsevier.nlrlocaterlithos Metasomatic alteration associated with regional metamorphism: an example from the Willyama Supergroup, South Australia A.J.R. Kent a,),1, P.M. Ashley a,2, C.M. Fanning b,3 a DiÕision of Earth Sciences, UniÕersity of New England, Armidale, NSW, 2351, Australia b Research School of Earth Sciences, The Australian National UniÕersity, Canberra, ACT, 0200, Australia Received 20 October 1998; accepted 12 May 2000 Abstract The Olary Domain, part of the Curnamona Province, a major Proterozoic terrane located within eastern South Australia and western New South Wales, Australia, is an excellent example of geological region that has been significantly altered by metasomatic mass-transfer processes associated with regional metamorphism. Examples of metasomatically altered rocks in the Olary Domain are ubiquitous and include garnet±epidote-rich alteration zones, clinopyroxene- and actinolite-matrix breccias, replacement ironstones and albite-rich alteration zones in quartzofeldspathic metasediments and intrusive rocks. Metasomatism is typically associated with formation of calcic, sodic andror iron-rich alteration zones and development of oxidised mineral assemblages containing one or more of the following: quartz, albite, actinolite±hornblende, andradite-rich garnet, epidote, magnetite, hematite and aegerine-bearing clinopyroxene. Detailed study of one widespread style of metasomatic alteration, garnet±epidote-rich alteration zones in calc-silicate host rocks, provides detailed information on the timing of metasomatism, the conditions under which alteration occurred, and the nature and origin of the metasomatic fluids. Garnet±epidote-bearing zones exhibit features such as breccias, veins, fracture-controlled alteration, open space fillings and massive replacement of pre-existing calc-silicate rock consistent with formation at locally high fluid pressures and fluidrrock ratios. -
Controls on the Expression of Igneous Intrusions in Seismic Reflection Data GEOSPHERE; V
Research Paper GEOSPHERE Controls on the expression of igneous intrusions in seismic reflection data GEOSPHERE; v. 11, no. 4 Craig Magee, Shivani M. Maharaj, Thilo Wrona, and Christopher A.-L. Jackson Basins Research Group (BRG), Department of Earth Science and Engineering, Imperial College, 39 Prince Consort Road, London SW7 2BP, UK doi:10.1130/GES01150.1 14 figures; 2 tables ABSTRACT geometries in the field is, however, hampered by a lack of high-quality, fully CORRESPONDENCE: [email protected] three-dimensional (3-D) exposures and the 2-D nature of the Earth’s surface The architecture of subsurface magma plumbing systems influences a va- (Fig. 1). Geophysical techniques such as magnetotellurics, InSAR (interfero- CITATION: Magee, C., Maharaj, S.M., Wrona, T., riety of igneous processes, including the physiochemical evolution of magma metric synthetic aperture radar), and reflection seismology have therefore and Jackson, C.A.-L., 2015, Controls on the expres- sion of igneous intrusions in seismic reflection data: and extrusion sites. Seismic reflection data provides a unique opportunity to been employed to either constrain subsurface intrusions or track real-time Geosphere, v. 11, no. 4, p. 1024–1041, doi: 10 .1130 image and analyze these subvolcanic systems in three dimensions and has magma migration (e.g., Smallwood and Maresh, 2002; Wright et al., 2006; /GES01150.1. arguably revolutionized our understanding of magma emplacement. In par- Biggs et al., 2011; Pagli et al., 2012). Of these techniques, reflection seismol- ticular, the observation of (1) interconnected sills, (2) transgressive sill limbs, ogy arguably provides the most complete and detailed imaging of individual Received 11 November 2014 and (3) magma flow indicators in seismic data suggest that sill complexes intrusions and intrusion systems. -
Are Plutons Assembled Over Millions of Years by Amalgamation From
1996; Petford et al., 2000). If plutons are emplaced by bulk magmatic flow, then during emplacement, the magma must Are plutons assembled contain a melt fraction of at least 30–50 vol% (Vigneresse et al., 1996). At lower melt fractions, crystals in the melt are welded to their neighbors; thus, a low melt-fraction material over millions of years by probably is better regarded not as magma but as a solid with melt-filled pore spaces because bulk flow of such a material requires pervasive solid-state deformation. amalgamation from small The concept of plutons as large ascending molten blobs (Fig. 1) is widespread in geologic thought and commonly magma chambers? guides interpretation of field relations (e.g., Buddington, 1959; Miller et al., 1988; Clarke, 1992; Bateman, 1992; Miller and Paterson, 1999). A contrasting view is that diapiric as- Allen F. Glazner, Department of Geological Sciences, cent of magma is too slow and energetically inefficient to be CB#3315, University of North Carolina, Chapel Hill, North geologically important, and large magma bodies only form Carolina 27599, USA, [email protected] at the emplacement level where they are fed by dikes (e.g., John M. Bartley, Department of Geology and Geophysics, Clemens and Mawer, 1992; Petford et al., 2000). Several lines University of Utah, Salt Lake City, Utah 84112, USA of evidence indicate that, regardless of the ascent mechanism, Drew S. Coleman, Walt Gray*, and Ryan Z. Taylor*, at least some plutons were emplaced incrementally over time Department of Geological Sciences, CB#3315, University of spans an order of magnitude longer than the thermal lifetime North Carolina, Chapel Hill, North Carolina 27599, USA of a large magmatic mass (Coleman et al., 2004). -
The Nakhlite Meteorites: Augite-Rich Igneous Rocks from Mars ARTICLE
ARTICLE IN PRESS Chemie der Erde 65 (2005) 203–270 www.elsevier.de/chemer INVITED REVIEW The nakhlite meteorites: Augite-rich igneous rocks from Mars Allan H. Treiman Lunar and Planetary Institute, 3600 Bay Area Boulevard, Houston, TX 77058-1113, USA Received 22 October 2004; accepted 18 January 2005 Abstract The seven nakhlite meteorites are augite-rich igneous rocks that formed in flows or shallow intrusions of basaltic magma on Mars. They consist of euhedral to subhedral crystals of augite and olivine (to 1 cm long) in fine-grained mesostases. The augite crystals have homogeneous cores of Mg0 ¼ 63% and rims that are normally zoned to iron enrichment. The core–rim zoning is cut by iron-enriched zones along fractures and is replaced locally by ferroan low-Ca pyroxene. The core compositions of the olivines vary inversely with the steepness of their rim zoning – sharp rim zoning goes with the most magnesian cores (Mg0 ¼ 42%), homogeneous olivines are the most ferroan. The olivine and augite crystals contain multiphase inclusions representing trapped magma. Among the olivine and augite crystals is mesostasis, composed principally of plagioclase and/or glass, with euhedra of titanomagnetite and many minor minerals. Olivine and mesostasis glass are partially replaced by veinlets and patches of iddingsite, a mixture of smectite clays, iron oxy-hydroxides and carbonate minerals. In the mesostasis are rare patches of a salt alteration assemblage: halite, siderite, and anhydrite/ gypsum. The nakhlites are little shocked, but have been affected chemically and biologically by their residence on Earth. Differences among the chemical compositions of the nakhlites can be ascribed mostly to different proportions of augite, olivine, and mesostasis. -
Evidence for a Carbonatite-Influenced Source Assemblage for Intraplate
minerals Article Evidence for a Carbonatite-Influenced Source Assemblage for Intraplate Basalts from the Buckland Volcanic Province, Queensland, Australia Joshua J. Shea * and Stephen F. Foley Department Earth and Planetary Sciences and ARC Centre of Excellence for Core to Crust Fluid Systems, Macquarie University, North Ryde 2109, New South Wales, Australia * Correspondence: [email protected] Received: 20 June 2019; Accepted: 7 September 2019; Published: 10 September 2019 Abstract: Eastern Australia contains a widespread suite of primitive (MgO 7.5 wt.%) intraplate ≥ basaltic provinces, including those sited along the longest continental hotspot track on Earth ( 2000 km), the Cosgrove track. The Buckland volcanic province is the most southerly basaltic ≈ province on the Cosgrove track before a >1600 km stretch that contains only sparse leucitite volcanism. Buckland is also situated just northeast of the edge of thick cratonic lithosphere where it transitions to a thinner continental lithosphere (<110 km) to the east, which may influence the production of plume-derived melts. Here, analysis of minor and trace elements in olivines in alkali basalts and basanites from the Buckland Province are combined with whole-rock compositions to elucidate the mantle source assemblages, and to calibrate minor and trace element indicators in olivine for application to source mineralogy. Olivine xenocrysts show element concentration ranges typical for peridotites; Mn and Al concentrations indicate that the ambient mantle is spinel, rather than garnet, peridotite. High modal pyroxene content is indicated by high Ni, Zn/Fe, and Fe/Mn in olivines, while high Ti/Sc is consistent with amphibole in the source. Residual phlogopite in the source of the basanites is indicated by low K/Nb in whole rocks, while apatite contains high P2O5 and low Rb/Sr ( 0.015) and Sr/La ( 13). -
Magmatic and Tectonic History of the Leech
Geological Society of America Special Paper 371 2003 Magmatic and tectonic history of the Leech River Complex, Vancouver Island, British Columbia: Evidence for ridge-trench intersection and accretion of the Crescent Terrane Wesley G. Groome* Derek J. Thorkelson Department of Earth Sciences, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada Richard M. Friedman James K. Mortensen Department of Earth and Ocean Sciences, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada Nick W.D. Massey British Columbia Geological Survey Branch, Ministry of Energy and Mines, Victoria, British Columbia, V8W 9N3, Canada Daniel D. Marshall Department of Earth Sciences, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada Paul W. Layer Geophysical Institute, University of Alaska, Fairbanks, Alaska, 99775, USA ABSTRACT The Leech River Complex, part of the Pacifi c Rim Terrane, is a Cretaceous metasedimentary and metaigneous assemblage on southern Vancouver Island. The Leech River Complex is fault-bounded between the Eocene Metchosin Igneous Com- plex to the south (part of the Crescent Terrane) and the Paleozoic to Jurassic Wrangel Terrane to the north and provides critical information on the evolution of the central part of the western North American forearc in Cretaceous through Eocene time. Sin- gle detrital zircons from the metasedimentary component, known as the Leech River Schist, give U-Pb interpreted ages that range from Precambrian to ca. 103 Ma, indi- cating a varied source region and a probable Early Cretaceous depositional age. U-Pb geochronology and fi eld investigations indicate at least two magmatic-metamorphic events in the Leech River Complex: one during the Late Cretaceous, and the other during the early Middle Eocene. -
How Is Radon Related to Rocks, Soils, and Uranium?
Earth Science Unit Radon Alert TEACHER'S NOTES 1 HOW IS RADON RELATED TO ROCKS, SOILS, AND URANIUM? BACKGROUND In preparation for this lesson, students should have basic knowledge of: • three basic rock types • difference between rocks and minerals • rock formation processes • movement of geologic materials in groundwater. Rocks are the solid materials, or building blocks, that make up the earth’s crust. Each rock is made up of one or more different minerals. For example, granite might be composed of the minerals quartz, orthoclase feldspar, mica, and hornblende. Limestone is an example of a rock that consists of only one kind of mineral: calcite. Although there are 2000 or more kinds of minerals in the earth, only about a dozen or so are common. These include plagioclase feldspar, orthoclase feldspar, quartz, augite, hornblende, and mica. Each rock type varies somewhat in its mineral content. All granites, for example, contain quartz and feldspar; these are essential minerals in granite. Granite may or may not contain hornblende, an accessory mineral in granite. Furthermore, the proportions of the different minerals can vary from sample to sample. Thus, granites can be different colors. Those high in quartz and feldspar tend to be lighter in color. Those containing greater amounts of darker minerals, like biotite mica, will be darker in color. Igneous rocks that harden from magma under the surface are called intrusive rocks. Those that form by hardening of lava above ground are called extrusive, or volcanic. Intrusive and extrusive igneous rocks differ in texture, which is determined by the size and arrangement of the mineral crystals in the rock.