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Report 2010–5070–F Occurrence Model for Volcanogenic Beryllium Deposits Chapter F of Mineral Deposit Models for Resource Assessment Scientific Investigation Report 2010–5070–F U.S. Department of the Interior U.S. Geological Survey COVER. Sample of large layered nodule from the Roadside pit showing fluorite, opal, and bertrandite mineralization. The nodule has an interior of fine-grained quartz, fluorite, and opal, an intermediate zone of black chalcedonic quartz, and an outer zone of white opal with minor fluorite. Beryllium is concentrated in the outer opal-fluorite zone; such samples can contain as much as 1-percent beryllium as bertrandite. Size of the sample is 16×12 centimeters (photograph by David A. Lindsey, Emeritus, U.S. Geological Survey). Occurrence Model for Volcanogenic Beryllium Deposits By Nora K. Foley, Albert H. Hofstra, David A. Lindsey, Robert R. Seal, II, Brian Jaskula, and Nadine M. Piatak Chapter F of Mineral Deposit Models for Resource Assessment Scientific Investigation Report 2010–5070–F 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: 2012 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, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner. Suggested citation: Foley, N.K., Hofstra, A.H., Lindsey, D.A., Seal, R.R., II, Jaskula, Brian, and Piatak, N.M., 2012, Occurrence model for volcanogenic beryllium deposits, chap. F of Mineral deposit models for resource assessment: U.S. Geological Survey Scientific Investigations Report 2010–5070–F, 43 p. iii Contents Abstract ...........................................................................................................................................................1 Introduction.....................................................................................................................................................1 Overview.................................................................................................................................................1 Scope and Purpose ..............................................................................................................................3 Deposit Type and Associated Commodities ..............................................................................................3 Name.... ...................................................................................................................................................3 Synonyms ...............................................................................................................................................3 Brief Description ...................................................................................................................................5 Associated Deposit Types ...................................................................................................................6 Fluorite Breccia Pipe Deposits ..................................................................................................6 Carbonate-Hosted Epithermal Beryllium Deposits ................................................................6 Volcanogenic Uranium Deposits ...............................................................................................6 Gem Beryl Deposits .....................................................................................................................8 Beryllium-Fluorine Skarn-Greisen Deposits ............................................................................8 Primary and Byproduct Commodities .......................................................................................9 Example Deposits..................................................................................................................................9 Metallogenic Provinces and Epochs ...............................................................................................10 Historical Evolution of Descriptive and Genetic Knowledge and Concepts ......................................10 Regional Environment .................................................................................................................................11 Geotectonic Environment ..................................................................................................................11 Geologic Setting of Spor Mountain Deposits ........................................................................12 Duration of the Magmatic-Hydrothermal System and Mineralizing Processes ......................16 Duration of Spor Mountain System ........................................................................................16 Relations to Structures ......................................................................................................................16 Relations to Igneous Rocks ...............................................................................................................17 Relations to Sedimentary Rocks ......................................................................................................17 Relations to Metamorphic Rocks .....................................................................................................17 Physical Description of Deposit ................................................................................................................17 Deposit Dimensions ............................................................................................................................17 Structural Setting(s) and Controls ...................................................................................................18 Geophysical Characteristics .............................................................................................................18 Hypogene Ore and Gangue Characteristics ...........................................................................................18 Mineralogy and Mineral Assemblages ...........................................................................................18 Paragenesis .........................................................................................................................................20 Zoning Patterns ...................................................................................................................................22 Hydrothermal Alteration .............................................................................................................................22 Argillic and Feldspathic Alteration ..................................................................................................23 Kaolinitization ......................................................................................................................................24 Supergene Ore Characteristics and Processes .....................................................................................24 Geochemical Characteristics ....................................................................................................................25 Trace Elements and Element Associations ....................................................................................25 Zoning Patterns ...................................................................................................................................25 Fluid-Inclusion Microthermometry ..................................................................................................25 iv Stable Isotope Geochemistry ...........................................................................................................25 Radiogenic Isotope Geochemistry of Ore .......................................................................................25 Depositional Process .........................................................................................................................26 Petrology of Associated Igneous Rocks ..................................................................................................27 Petrology of Associated Sedimentary Rocks ..........................................................................................28 Petrology of Associated Metamorphic Rocks ........................................................................................29 Theory of Deposit Formation ......................................................................................................................29 Sequence of Events ............................................................................................................................29 Genetic Model .....................................................................................................................................29 Geoenvironmental Features and Anthropogenic Mining Effects ........................................................32
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