2010 the Annual Report for the Paleoproterozoic Mineralization Research Group
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Podiform Chromite Deposits—Database and Grade and Tonnage Models
Podiform Chromite Deposits—Database and Grade and Tonnage Models Scientific Investigations Report 2012–5157 U.S. Department of the Interior U.S. Geological Survey COVER View of the abandoned Chrome Concentrating Company mill, opened in 1917, near the No. 5 chromite mine in Del Puerto Canyon, Stanislaus County, California (USGS photograph by Dan Mosier, 1972). Insets show (upper right) specimen of massive chromite ore from the Pillikin mine, El Dorado County, California, and (lower left) specimen showing disseminated layers of chromite in dunite from the No. 5 mine, Stanislaus County, California (USGS photographs by Dan Mosier, 2012). Podiform Chromite Deposits—Database and Grade and Tonnage Models By Dan L. Mosier, Donald A. Singer, Barry C. Moring, and John P. Galloway Scientific Investigations Report 2012-5157 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 This report and any updates to it are available online at: http://pubs.usgs.gov/sir/2012/5157/ 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 Suggested citation: Mosier, D.L., Singer, D.A., Moring, B.C., and Galloway, J.P., 2012, Podiform chromite deposits—database and grade and tonnage models: U.S. -
Chapter 9 Gold-Rich Porphyry Deposits: Descriptive and Genetic Models and Their Role in Exploration and Discovery
SEG Reviews Vol. 13, 2000, p. 315–345 Chapter 9 Gold-Rich Porphyry Deposits: Descriptive and Genetic Models and Their Role in Exploration and Discovery RICHARD H. SILLITOE 27 West Hill Park, Highgate Village, London N6 6ND, England Abstract Gold-rich porphyry deposits worldwide conform well to a generalized descriptive model. This model incorporates six main facies of hydrothermal alteration and mineralization, which are zoned upward and outward with respect to composite porphyry stocks of cylindrical form atop much larger parent plutons. This intrusive environment and its overlying advanced argillic lithocap span roughly 4 km vertically, an interval over which profound changes in the style and mineralogy of gold and associated copper miner- alization are observed. The model predicts a number of geologic attributes to be expected in association with superior gold-rich porphyry deposits. Most features of the descriptive model are adequately ex- plained by a genetic model that has developed progressively over the last century. This model is domi- nated by the consequences of the release and focused ascent of metalliferous fluid resulting from crys- tallization of the parent pluton. Within the porphyry system, gold- and copper-bearing brine and acidic volatiles interact in a complex manner with the stock, its wall rocks, and ambient meteoric and connate fluids. Although several processes involved in the evolution of gold-rich porphyry deposits remain to be fully clarified, the fundamental issues have been resolved to the satisfaction of most investigators. Explo- ration for gold-rich porphyry deposits worldwide involves geologic, geochemical, and geophysical work but generally employs the descriptive model in an unsophisticated manner and the genetic model hardly at all. -
The Sauropodomorph Biostratigraphy of the Elliot Formation of Southern Africa: Tracking the Evolution of Sauropodomorpha Across the Triassic–Jurassic Boundary
Editors' choice The sauropodomorph biostratigraphy of the Elliot Formation of southern Africa: Tracking the evolution of Sauropodomorpha across the Triassic–Jurassic boundary BLAIR W. MCPHEE, EMESE M. BORDY, LARA SCISCIO, and JONAH N. CHOINIERE McPhee, B.W., Bordy, E.M., Sciscio, L., and Choiniere, J.N. 2017. The sauropodomorph biostratigraphy of the Elliot Formation of southern Africa: Tracking the evolution of Sauropodomorpha across the Triassic–Jurassic boundary. Acta Palaeontologica Polonica 62 (3): 441–465. The latest Triassic is notable for coinciding with the dramatic decline of many previously dominant groups, followed by the rapid radiation of Dinosauria in the Early Jurassic. Among the most common terrestrial vertebrates from this time, sauropodomorph dinosaurs provide an important insight into the changing dynamics of the biota across the Triassic–Jurassic boundary. The Elliot Formation of South Africa and Lesotho preserves the richest assemblage of sauropodomorphs known from this age, and is a key index assemblage for biostratigraphic correlations with other simi- larly-aged global terrestrial deposits. Past assessments of Elliot Formation biostratigraphy were hampered by an overly simplistic biozonation scheme which divided it into a lower “Euskelosaurus” Range Zone and an upper Massospondylus Range Zone. Here we revise the zonation of the Elliot Formation by: (i) synthesizing the last three decades’ worth of fossil discoveries, taxonomic revision, and lithostratigraphic investigation; and (ii) systematically reappraising the strati- graphic provenance of important fossil locations. We then use our revised stratigraphic information in conjunction with phylogenetic character data to assess morphological disparity between Late Triassic and Early Jurassic sauropodomorph taxa. Our results demonstrate that the Early Jurassic upper Elliot Formation is considerably more taxonomically and morphologically diverse than previously thought. -
The Anatomy and Phylogenetic Relationships of Antetonitrus Ingenipes (Sauropodiformes, Dinosauria): Implications for the Origins of Sauropoda
THE ANATOMY AND PHYLOGENETIC RELATIONSHIPS OF ANTETONITRUS INGENIPES (SAUROPODIFORMES, DINOSAURIA): IMPLICATIONS FOR THE ORIGINS OF SAUROPODA Blair McPhee A dissertation submitted to the Faculty of Science, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master of Science. Johannesburg, 2013 i ii ABSTRACT A thorough description and cladistic analysis of the Antetonitrus ingenipes type material sheds further light on the stepwise acquisition of sauropodan traits just prior to the Triassic/Jurassic boundary. Although the forelimb of Antetonitrus and other closely related sauropododomorph taxa retains the plesiomorphic morphology typical of a mobile grasping structure, the changes in the weight-bearing dynamics of both the musculature and the architecture of the hindlimb document the progressive shift towards a sauropodan form of graviportal locomotion. Nonetheless, the presence of hypertrophied muscle attachment sites in Antetonitrus suggests the retention of an intermediary form of facultative bipedality. The term Sauropodiformes is adopted here and given a novel definition intended to capture those transitional sauropodomorph taxa occupying a contiguous position on the pectinate line towards Sauropoda. The early record of sauropod diversification and evolution is re- examined in light of the paraphyletic consensus that has emerged regarding the ‘Prosauropoda’ in recent years. iii ACKNOWLEDGEMENTS First, I would like to express sincere gratitude to Adam Yates for providing me with the opportunity to do ‘real’ palaeontology, and also for gladly sharing his considerable knowledge on sauropodomorph osteology and phylogenetics. This project would not have been possible without the continued (and continual) support (both emotionally and financially) of my parents, Alf and Glenda McPhee – Thank you. -
Platinum Group Minerals in Eastern Brazil GEOLOGY and OCCURRENCES in CHROMITITE and PLACERS
DOI: 10.1595/147106705X24391 Platinum Group Minerals in Eastern Brazil GEOLOGY AND OCCURRENCES IN CHROMITITE AND PLACERS By Nelson Angeli Department of Petrology and Metallogeny, University of São Paulo State (UNESP), 24-A Avenue, 1515, Rio Claro (SP), 13506-710, Brazil; E-mail: [email protected] Brazil does not have working platinum mines, nor even large reserves of the platinum metals, but there is platinum in Brazil. In this paper, four massifs (mafic/ultramafic complexes) in eastern Brazil, in the states of Minas Gerais and Ceará, where platinum is found will be described. Three of these massifs contain concentrations of platinum group minerals or platinum group elements, and gold, associated with the chromitite rock found there. In the fourth massif, in Minas Gerais State, the platinum group elements are found in alluvial deposits at the Bom Sucesso occurrence. This placer is currently being studied. The platinum group metals occur in specific Rh and Os occur together in minerals in various areas of the world: mainly South Africa, Russia, combinations. This particular PGM distribution Canada and the U.S.A. Geological occurrences of can also form noble metal alloys (7), and minerali- platinum group elements (PGEs) (and sometimes sation has been linked to crystallisation during gold (Au)) are usually associated with Ni-Co-Cu chromite precipitation of hydrothermal origin. sulfide deposits formed in layered igneous intru- In central Brazil there are massifs (Americano sions. The platinum group minerals (PGMs) are do Brasil and Barro Alto) that as yet are little stud- associated with the more mafic parts of the layered ied, and which are thought to contain small PGM magma deposit, and PGEs are found in chromite concentrations. -
The Pelvic and Hind Limb Anatomy of the Stem-Sauropodomorph Saturnalia Tupiniquim (Late Triassic, Brazil)
PaleoBios 23(2):1–30, July 15, 2003 © 2003 University of California Museum of Paleontology The pelvic and hind limb anatomy of the stem-sauropodomorph Saturnalia tupiniquim (Late Triassic, Brazil) MAX CARDOSO LANGER Department of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, BS8 1RJ Bristol, UK. Current address: Departamento de Biologia, Universidade de São Paulo (USP), Av. Bandeirantes, 3900 14040-901 Ribeirão Preto, SP, Brazil; [email protected] Three partial skeletons allow a nearly complete description of the sacrum, pelvic girdle, and hind limb of the stem- sauropodomorph Saturnalia tupiniquim, from the Late Triassic Santa Maria Formation, South Brazil. The new morphological data gathered from these specimens considerably improves our knowledge of the anatomy of basal dinosaurs, providing the basis for a reassessment of various morphological transformations that occurred in the early evolution of these reptiles. These include an increase in the number of sacral vertebrae, the development of a brevis fossa, the perforation of the acetabulum, the inturning of the femoral head, as well as various modifications in the insertion of the iliofemoral musculature and the tibio-tarsal articulation. In addition, the reconstruction of the pelvic musculature of Saturnalia, along with a study of its locomotion pattern, indicates that the hind limb of early dinosaurs did not perform only a fore-and-aft stiff rotation in the parasagittal plane, but that lateral and medial movements of the leg were also present and important. INTRODUCTION sisting of most of the presacral vertebral series, both sides Saturnalia tupiniquim was described in a preliminary of the pectoral girdle, right humerus, partial right ulna, right fashion by Langer et al. -
Geological Survey
DEPARTMENT OF THE INTERIOR UNITED STATES GEOLOGICAL SURVEY ISTo. 162 WASHINGTON GOVERNMENT PRINTING OFFICE 1899 UNITED STATES GEOLOGICAL SUEVEY CHAKLES D. WALCOTT, DIRECTOR Olf NORTH AMERICAN GEOLOGY, PALEONTOLOGY, PETROLOGY, AND MINERALOGY FOR THE YEAR 1898 BY FRED BOUG-HTOISr WEEKS WASHINGTON GOVERNMENT PRINTING OFFICE 1899 CONTENTS, Page. Letter of transmittal.......................................... ........... 7 Introduction................................................................ 9 List of publications examined............................................... 11 Bibliography............................................................... 15 Classified key to the index .................................................. 107 Indiex....................................................................... 113 LETTER OF TRANSMITTAL. DEPARTMENT OF THE INTERIOR, UNITED STATES GEOLOGICAL SURVEY. Washington, D. C., June 30,1899. SIR: I have the honor to transmit herewith the manuscript of a Bibliography and Index o'f North American Geology, Paleontology, Petrology, and Mineralogy for the Year 1898, and to request that it be published as a bulletin of the Survey. Very respectfully, F. B. WEEKS. Hon. CHARLES D. WALCOTT, Director United States Geological Survey. 1 I .... v : BIBLIOGRAPHY AND INDEX OF NORTH AMERICAN GEOLOGY, PALEONTOLOGY, PETROLOGY, AND MINERALOGY FOR THE YEAR 1898. ' By FEED BOUGHTON WEEKS. INTRODUCTION. The method of preparing and arranging the material of the Bibli ography and Index for 1898 is similar to that adopted for the previous publications 011 this subject (Bulletins Nos. 130,135,146,149, and 156). Several papers that should have been entered in the previous bulletins are here recorded, and the date of publication is given with each entry. Bibliography. The bibliography consists of full titles of separate papers, classified by authors, an abbreviated reference to the publica tion in which the paper is printed, and a brief summary of the con tents, each paper being numbered for index reference. -
PAL E1059.Pdf
Downloaded from rspb.royalsocietypublishing.org on November 23, 2010 A new transitional sauropodomorph dinosaur from the Early Jurassic of South Africa and the evolution of sauropod feeding and quadrupedalism Adam M. Yates, Matthew F. Bonnan, Johann Neveling, Anusuya Chinsamy and Marc G. Blackbeard Proc. R. Soc. B 2010 277, 787-794 first published online 11 November 2009 doi: 10.1098/rspb.2009.1440 Supplementary data "Data Supplement" http://rspb.royalsocietypublishing.org/content/suppl/2009/11/09/rspb.2009.1440.DC1.h tml References This article cites 24 articles, 5 of which can be accessed free http://rspb.royalsocietypublishing.org/content/277/1682/787.full.html#ref-list-1 Subject collections Articles on similar topics can be found in the following collections palaeontology (132 articles) taxonomy and systematics (296 articles) evolution (2213 articles) Receive free email alerts when new articles cite this article - sign up in the box at the top Email alerting service right-hand corner of the article or click here To subscribe to Proc. R. Soc. B go to: http://rspb.royalsocietypublishing.org/subscriptions This journal is © 2010 The Royal Society Downloaded from rspb.royalsocietypublishing.org on November 23, 2010 Proc. R. Soc. B (2010) 277, 787–794 doi:10.1098/rspb.2009.1440 Published online 11 November 2009 A new transitional sauropodomorph dinosaur from the Early Jurassic of South Africa and the evolution of sauropod feeding and quadrupedalism Adam M. Yates1,*, Matthew F. Bonnan2, Johann Neveling3, Anusuya Chinsamy4 and Marc G. Blackbeard1 1Bernard Price Institute for Palaeontological Research, University of the Witwatersrand, Johannesburg 2050, South Africa 2Department of Biological Sciences, Western Illinois University, Macomb, IL 61455, USA 3Council for Geoscience, Pretoria 0001, South Africa 4Zoology Department, University of Cape Town, Private Bag X3, Rhodes Gift 7700, South Africa Aardonyx celestae gen. -
Origin of Platinum Group Minerals (PGM) Inclusions in Chromite Deposits of the Urals
minerals Article Origin of Platinum Group Minerals (PGM) Inclusions in Chromite Deposits of the Urals Federica Zaccarini 1,*, Giorgio Garuti 1, Evgeny Pushkarev 2 and Oskar Thalhammer 1 1 Department of Applied Geosciences and Geophysics, University of Leoben, Peter Tunner Str.5, A 8700 Leoben, Austria; [email protected] (G.G.); [email protected] (O.T.) 2 Institute of Geology and Geochemistry, Ural Branch of the Russian Academy of Science, Str. Pochtovy per. 7, 620151 Ekaterinburg, Russia; [email protected] * Correspondence: [email protected]; Tel.: +43-3842-402-6218 Received: 13 August 2018; Accepted: 28 August 2018; Published: 31 August 2018 Abstract: This paper reviews a database of about 1500 published and 1000 unpublished microprobe analyses of platinum-group minerals (PGM) from chromite deposits associated with ophiolites and Alaskan-type complexes of the Urals. Composition, texture, and paragenesis of unaltered PGM enclosed in fresh chromitite of the ophiolites indicate that the PGM formed by a sequence of crystallization events before, during, and probably after primary chromite precipitation. The most important controlling factors are sulfur fugacity and temperature. Laurite and Os–Ir–Ru alloys are pristine liquidus phases crystallized at high temperature and low sulfur fugacity: they were trapped in the chromite as solid particles. Oxygen thermobarometry supports that several chromitites underwent compositional equilibration down to 700 ◦C involving increase of the Fe3/Fe2 ratio. These chromitites contain a great number of PGM including—besides laurite and alloys—erlichmanite, Ir–Ni–sulfides, and Ir–Ru sulfarsenides formed by increasing sulfur fugacity. Correlation with chromite composition suggests that the latest stage of PGM crystallization might have occurred in the subsolidus. -
Elachistosuchus Huenei Janensch, 1949 (Reptilia: Diapsida) from the Upper Triassic of Germany and Its Relevance for the Origin of Sauria
RESEARCH ARTICLE Anatomy of the Enigmatic Reptile Elachistosuchus huenei Janensch, 1949 (Reptilia: Diapsida) from the Upper Triassic of Germany and Its Relevance for the Origin of Sauria Gabriela Sobral1☯*, Hans-Dieter Sues2☯, Johannes Müller1☯ 1 Museum für Naturkunde Berlin, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Berlin, Germany, 2 Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, MRC 121, Washington, DC, United States of America ☯ These authors contributed equally to this work. * [email protected] OPEN ACCESS Citation: Sobral G, Sues H-D, Müller J (2015) Abstract Anatomy of the Enigmatic Reptile Elachistosuchus huenei Janensch, 1949 (Reptilia: Diapsida) from the The holotype and only known specimen of the enigmatic small reptile Elachistosuchus hue- Upper Triassic of Germany and Its Relevance for the nei Janensch, 1949 from the Upper Triassic (Norian) Arnstadt Formation of Saxony-Anhalt Origin of Sauria. PLoS ONE 10(9): e0135114. μ doi:10.1371/journal.pone.0135114 (Germany) is redescribed using CT scans of the material. This re-examination revealed new information on the morphology of this taxon, including previously unknown parts of the Editor: Shree Ram Singh, National Cancer Institute, UNITED STATES skeleton such as the palate, braincase, and shoulder girdle. Elachistosuchus is diagnosed especially by the presence of the posterolateral process of the frontal, the extension of the Received: January 27, 2015 maxillary tooth row to the posterior margin of the orbit, the free posterior process of the Accepted: July 19, 2015 jugal, and the notched anterior margin of the interclavicle. Phylogenetic analyses using two Published: September 9, 2015 recently published character-taxon matrices recovered conflicting results for the phyloge- Copyright: This is an open access article, free of all netic position of Elachistosuchus–either as an archosauromorph, as a lepidosauromorph or copyright, and may be freely reproduced, distributed, as a more basal, non-saurian diapsid. -
MINERALOGY and MINERAL CHEMISTRY of NOBLE METAL GRAINS in R CHONDRITES. H. Schulze, Museum Für Naturkunde, Institut Für Mineralogie, Invalidenstr
Lunar and Planetary Science XXX 1720.pdf MINERALOGY AND MINERAL CHEMISTRY OF NOBLE METAL GRAINS IN R CHONDRITES. H. Schulze, Museum für Naturkunde, Institut für Mineralogie, Invalidenstr. 43, D-10115 Berlin, Germany, hart- [email protected]. Introduction: Rumuruti-chondrites are a group of [1]. Mostly, NM grains can be encountered as mono- chondrites intermediate between ordinary and carbo- mineralic grains, but multiphase assemblages of two naceous chondrites [1]. The characteristic feature of or three phases were found as well. Host phase of most these chondrites is their highly oxidized mineral as- NM grains are sulfides, either intact like in Rumuruti semblage. Equilibrated olivine usually has a fayalite or weathered to Fe-hydroxides in the desert finds. content around ~39 mole-% Fa. There is almost no Also silicates are frequent host phases (mostly olivine free NiFe-metal in these chondrites [1]. As a conse- and plagioclase). Several grains were found in or ad- quence, noble metals form separate phases [1,2,3] jacent to chromite. which otherwise, due to their siderophilic behavior, Mineralogy and mineral chemistry: Table 1 lists certainly would be dissolved in the FeNi metal. De- the NM minerals detected in R chondrites. Summa- spite the occurrence of noble metal minerals the rizing the results for all R chondrites, tetraferroplati- chemistry does not show any enrichment in these ele- num, sperrylite, irarsite, and osmium are the most ments which are CI-like except for very volatile and abundant NM minerals. Gold seems to be a common chalcophile elements which are even lower [4]. Noble phase, too, but was not so frequently observed due to metal grains were described so far from carbonaceous the lower chemical abundance. -
ECONOMIC GEOLOGY RESEARCH INSTITUTE HUGH ALLSOPP LABORATORY University of the Witwatersrand Johannesburg
2 ECONOMIC GEOLOGY RESEARCH INSTITUTE HUGH ALLSOPP LABORATORY University of the Witwatersrand Johannesburg ! GEOLOGICAL CHARACTERISTICS OF PGE-BEARING LAYERED INTRUSIONS IN SOUTHWEST SICHUAN PROVINCE, CHINA Y.YAO, M.J. VILJOEN, R.P. VILJOEN, A.H. WILSON, H. ZHONG, B.G. LIU, H.L. YING, G.Z. TU and N. LUO ! INFORMATION CIRCULAR No. 358 3 UNIVERSITY OF THE WITWATERSRAND JOHANNESBURG GEOLOGICAL CHARACTERISTICS OF PGE-BEARING LAYERED INTRUSIONS IN SOUTHWEST SICHUAN PROVINCE, CHINA by Y. YAO1, M. J. VILJOEN2, R. P. VILJOEN2, A. H. WILSON3, H. ZHONG1, B. G. LIU4, H. L. YING4, G. Z. TU4 AND Y. N. LUO5, ( 1 Economic Geology Research Institute, School of Geosciences, University of the Witwatersrand, P/Bag 3, WITS 2050, Johannesburg, South Africa; 2 Department of Geology and CAMEG, School of Geosciences, University of the Witwatersrand, P/Bag 3, WITS 2050, Johannesburg, South Africa; 3 Department of Geology and Applied Geology, University of Natal, King George V Avenue, Durban, 4001; 4 Institute of Geology and Geophysics, Chinese Academy of Sciences, P.O. Box 9825, Qijiahuozhi, Deshengmenwai, Beijing 100029, P.R. China; 5 Geological Exploration Bureau of Sichuan Province, Renminglu, Chengdu 610081, P.R. China) ECONOMIC GEOLOGY RESEARCH UNIT INFORMATION CIRCULAR No. 358 December 2001 4 GEOLOGICAL CHARACTERISTICS OF PGE-BEARING LAYERED INTRUSIONS IN SOUTHWEST SICHUAN PROVINCE, CHINA ABSTRACT A number of platinum-group-element (PGE-bearing), layered, ultramafic-mafic intrusions in the Pan-Xi and Danba areas of the southwest Sichuan Province of China have been investigated. The two study areas are located, respectively, in the central and northern parts of the Kangding Axis on the western margin of the Yangtze Platform, a region geologically distinguished by late- Archaean to late-Proterozoic basement and by stable sedimentary sequences.