DOCSLIB.ORG

Geochronology and Geochemistry of the Nantianwan Mafic–Ultramafic

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Geochronology and Geochemistry of the Nantianwan Mafic–Ultramafic This article was downloaded by: [China University of Geosciences], [Mr Zhaochong Zhang] On: 15 October 2012, At: 20:59 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK International Geology Review Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/tigr20 Geochronology and geochemistry of the Nantianwan mafic–ultramafic complex, Emeishan large igneous province: metallogenesis of magmatic Ni–Cu sulphide deposits and geodynamic setting Meng Wang a , Zhaochong Zhang a , John Encarnacion b , Tong Hou a & Wenjuan Luo a a State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing, 100083, China b Department of Earth and Atmospheric Sciences, Saint Louis University, 3642 Lindell Boulevard, St. Louis, MO, 63108, USA Version of record first published: 08 Mar 2012. To cite this article: Meng Wang, Zhaochong Zhang, John Encarnacion, Tong Hou & Wenjuan Luo (2012): Geochronology and geochemistry of the Nantianwan mafic–ultramafic complex, Emeishan large igneous province: metallogenesis of magmatic Ni–Cu sulphide deposits and geodynamic setting, International Geology Review, 54:15, 1746-1764 To link to this article: http://dx.doi.org/10.1080/00206814.2012.668766 PLEASE SCROLL DOWN FOR ARTICLE Full terms and conditions of use: http://www.tandfonline.com/page/terms-and-conditions This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae, and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand, or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material. International Geology Review Vol. 54, No. 15, November 2012, 1746–1764 Geochronology and geochemistry of the Nantianwan mafic–ultramafic complex, Emeishan large igneous province: metallogenesis of magmatic Ni–Cu sulphide deposits and geodynamic setting Meng Wanga , Zhaochong Zhanga*, John Encarnacionb , Tong Houa and Wenjuan Luoa aState Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing 100083, China; bDepartment of Earth and Atmospheric Sciences, Saint Louis University, 3642 Lindell Boulevard, St. Louis, MO 63108, USA (Accepted 17 February 2012) The Nantianwan mafic–ultramafic complex is situated in the northwest part of the Panxi district, southwest China. It consists predominantly of gabbros, gabbronorites, and lherzolites. LA–ICP–MS U–Pb zircon dating of the gabbronorites yields an age of 259.7 ± 0.6 million years, consistent with the ages of other mafic–ultramafic intrusions in the Emeishan large igneous province (ELIP). Gabbronorites and lherzolites host Cu–Ni sulphide ores. Cumulus texture is pronounced in these rocks, containing magnesium-rich olivine (up to 81.4% forsterite). SiO2 contents of the lherzolites range from 42.93 to 44.18 wt.%, whereas those of the gabbronorites vary between 44.89 and 52.76 wt.%. Analysed samples have low rare earth element (REE) contents (23.22–30.16 ppm for lherzolites and 25.21–61.05 ppm for gabbronorites). Both lherzolites and gabbronorites have similar chondrite-normalized REE patterns, suggesting that they are comagmatic. All samples are slightly enriched in large ion lithophile elements (LILEs, e.g. Rb, Ba, and Sr) relative to high field strength elements (HFSEs, e.g. Nb, Ta, and Ti), very similar to those of ocean island basalts (OIBs). The presence of cumulus textures and geochemical signatures indicates that 87 86 fractional crystallization played an important role in the petrogenesis of these rocks. Initial ( Sr/ Sr)t (t = 260 Ma) ratios and εNd(t) values of the mafic–ultramafic suite vary from 0.70542 to 0.70763, and −0.4 to 1.7, respectively. Compared to the Cu–Ni-bearing Baimazhai and Limahe intrusions in the ELIP, which were considerably contaminated by variable crustal 87 86 materials, the Nantianwan complex exhibits much lower ( Sr/ Sr)t.TheirεNd(t) versus (Th/Nb)PM ratios also indicate that the ore-bearing magmas did not undergo significant crustal contamination. In combination with (Tb/Yb)PM versus (Yb/Sm)PM modelling, we infer that the magmas originated from an incompatible elements-enriched spinel-facies lherzolite that itself formed by interaction between the Emeishan plume and the lithospheric mantle. Most plots of NiO versus Fo contents of olivine suggest that sulphides are separated from the parental magma by liquid immiscibility, which is also supported by bulk-rock Cu/Zr ratios of the lherzolites (7.04–102.67) and gabbronorites (0.88–5.56). We suggest that the gabbronorites and lherzolites experienced undersaturation to oversaturation of sulphur; the latter may be due to fractional crystallization in a high-level magma chamber, accounting for the sulphide segregation. Keywords: Nantianwan complex; geochemistry; metallogenesis; Cu–Ni sulphide; Panxi region Introduction (platinum group element) sulphide deposits (e.g. Hou et al. The Emeishan igneous complex is a unique large igneous 2011). Particularly, it is well known for the presence of province (LIP) in China, widely recognized by the inter- the world’s largest Fe–Ti–V oxide ore cluster in the Panxi national geoscientific community. It is one of the three region (e.g. Zhang et al. 2009), where the scale of Cu–Ni– LIPs on Earth that formed near the end of the Permian in (PGE) mineralization is relatively small. In contrast, the widely separated locations, the others being the Siberian Siberian LIP is characterized by the world-class Noril’sk Traps (Sharma 1997; Dobretsov 2005) and the Panjal Cu–Ni–(PGE) sulphide deposits. The difference in miner- Traps of northwestern India (e.g. Bhat et al. 1981). The alization between these two Permian LIPs raises an impor- Emeishan large igneous province (ELIP) is thought to be tant question: what caused the different features of the ∼ Downloaded by [China University of Geosciences], [Mr Zhaochong Zhang] at 20:59 15 October 2012 genetically related to a major 260 Ma plume event (e.g. ore deposits: geologic settings, source composition, depth Thompson et al. 2001; Xu et al. 2004; Ali et al. 2010). of melting, lithospheric/crustal contamination, or magma Although the Permian ELIP is not as large as other LIPs chamber processes? (e.g. Zhang et al. 2006), it is one of the richest in min- Recently, small-scale Cu–Ni–(PGE) sulphide miner- eral resources and the only province in the world that hosts alization has been recognized in the Nantianwan mafic– both magmatic Fe–Ti–V oxide ores and Cu–Ni–(PGE) ultramafic complex in the Pingchuan area, Yanyuan *Corresponding author. Email: [email protected] ISSN 0020-6814 print/ISSN 1938-2839 online © 2012 Taylor & Francis http://dx.doi.org/10.1080/00206814.2012.668766 http://www.tandfonline.com International Geology Review 1747 county of Sichuan province, in the western part of the of clastic, carbonate, and metavolcanic rocks (SBGMR ELIP. Current exploration drilling is in progress by the 1991). The early Sinian consists of clastic rocks and 604 Geological Team, Geological and Mineral Resources felsic volcanic rocks, while the late Sinian Dengying Bureau, Sichuan, China. Sparsely disseminated Cu–Ni Formations consist of clastic rocks in the lower part and sulphide ores with a thickness of ∼350 m were recog- phosphorous-bearing carbonate rocks in the upper part. nized in one borehole. Unlike other Cu–Ni–(PGE) sulphide The Early Cambrian strata are characterized by clastic and deposits in the ELIP, such as the Limahe, Zhubu, and carbonate rocks, whereas the Middle–Late Cambrian strata Baimazhai, which are hosted by small sills, the volume are characterized by limestones (Zhulinping Formation) of the Nantianwan mafic–ultramafic intrusion is relatively and dolomitic limestones (Gaojiaping Formation). The large (39 km2). The prospect for large-scale Cu–Ni–(PGE) Early Silurian strata mainly consist of argillaceous rocks sulphide mineralization resembling those large Cu–Ni– and sandstones (Zhongcao Formation). The Ordovician (PGE) sulphide deposits such as Noril’sk and Sudbury strata consist of carbonate (Hongshiya Formation) and (Naldrett 1997, 1999) has aroused extensive interest. argillaceous rocks, whereas the Carboniferous strata con- However, except for a limited geological survey conducted sist of silicalites (Daopingzi Formation) and limestones at the scale of 1:50,000 and 1:200,000 in the Pingchuan (Maping Formation). The Permian Emeishan basaltic suc- area, no other detailed information has been documented cession unconformably overlies the limestones of the Early to date. Permian Maokou Formation (YBGMR 1990). In the Panxi In this article, we present the first geochronology, min- region, extensive erosion and thinning of the Middle eral chemical, bulk-rock major + trace element, and Sr–Nd Permian limestone in the central part of the ELIP indi- isotopic compositions, aimed at constraining the nature of cate kilometre-scale regional uplift linked to the rising the sources of the intrusions and the petrogenesis, which plume (He et al. 2003; Xu et al. 2004). Numerous in turn provide some key constraints on the metalloge- mafic–ultramafic intrusions are exposed along several nesis of Cu–Ni sulphide mineralization. These new data N–S-trending faults. These intrusions host major world- not only shed new light on the petrogenesis of the ELIP class Fe–Ti oxide deposits (Zhou et al. 2005, 2008). that we can apply to other provinces, but may also allow refinement of previously proposed exploration models for the same type of deposits in the region and around the Geology of the Nantianwan complex and associated world.
Load more

Recommended publications
  • Guadalupian, Middle Permian) Mass Extinction in NW Pangea (Borup Fiord, Arctic Canada): a Global Crisis Driven by Volcanism and Anoxia
    The Capitanian (Guadalupian, Middle Permian) mass extinction in NW Pangea (Borup Fiord, Arctic Canada): A global crisis driven by volcanism and anoxia David P.G. Bond1†, Paul B. Wignall2, and Stephen E. Grasby3,4 1Department of Geography, Geology and Environment, University of Hull, Hull, HU6 7RX, UK 2School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK 3Geological Survey of Canada, 3303 33rd Street N.W., Calgary, Alberta, T2L 2A7, Canada 4Department of Geoscience, University of Calgary, 2500 University Drive N.W., Calgary Alberta, T2N 1N4, Canada ABSTRACT ing gun of eruptions in the distant Emeishan 2009; Wignall et al., 2009a, 2009b; Bond et al., large igneous province, which drove high- 2010a, 2010b), making this a mid-Capitanian Until recently, the biotic crisis that oc- latitude anoxia via global warming. Although crisis of short duration, fulfilling the second cri- curred within the Capitanian Stage (Middle the global Capitanian extinction might have terion. Several other marine groups were badly Permian, ca. 262 Ma) was known only from had different regional mechanisms, like the affected in equatorial eastern Tethys Ocean, in- equatorial (Tethyan) latitudes, and its global more famous extinction at the end of the cluding corals, bryozoans, and giant alatocon- extent was poorly resolved. The discovery of Permian, each had its roots in large igneous chid bivalves (e.g., Wang and Sugiyama, 2000; a Boreal Capitanian crisis in Spitsbergen, province volcanism. Weidlich, 2002; Bond et al., 2010a; Chen et al., with losses of similar magnitude to those in 2018). In contrast, pelagic elements of the fauna low latitudes, indicated that the event was INTRODUCTION (ammonoids and conodonts) suffered a later, geographically widespread, but further non- ecologically distinct, extinction crisis in the ear- Tethyan records are needed to confirm this as The Capitanian (Guadalupian Series, Middle liest Lopingian (Huang et al., 2019).
    [Show full text]
  • Wrangellia Flood Basalts in Alaska, Yukon, and British Columbia: Exploring the Growth and Magmatic History of a Late Triassic Oceanic Plateau
    WRANGELLIA FLOOD BASALTS IN ALASKA, YUKON, AND BRITISH COLUMBIA: EXPLORING THE GROWTH AND MAGMATIC HISTORY OF A LATE TRIASSIC OCEANIC PLATEAU By ANDREW R. GREENE A THESIS SUBMITTED iN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE STUDIES (Geological Sciences) UNIVERSITY OF BRITISH COLUMBIA (Vancouver) August 2008 ©Andrew R. Greene, 2008 ABSTRACT The Wrangellia flood basalts are parts of an oceanic plateau that formed in the eastern Panthalassic Ocean (ca. 230-225 Ma). The volcanic stratigraphy presently extends >2300 km in British Columbia, Yukon, and Alaska. The field relationships, age, and geochemistry have been examined to provide constraints on the construction of oceanic plateaus, duration of volcanism, source of magmas, and the conditions of melting and magmatic evolution for the volcanic stratigraphy. Wrangellia basalts on Vancouver Island (Karmutsen Formation) form an emergent sequence consisting of basal sills, submarine flows (>3 km), pillow breccia and hyaloclastite (<1 1cm), and subaerial flows (>1.5 km). Karmutsen stratigraphy overlies Devonian to Permian volcanic arc (—‘380-355 Ma) and sedimentary sequences and is overlain by Late Triassic limestone. The Karmutsen basalts are predominantly homogeneous tholeiitic basalt (6-8 wt% MgO); however, the submarine part of the stratigraphy, on northern Vancouver Island, contains picritic pillow basalts (9-20 wt% MgO). Both lava groups have overlapping initial and ENd, indicating a common, ocean island basalt (OIB)-type Pacific mantle source similar to the source of basalts from the Ontong Java and Caribbean Plateaus. The major-element chemistry of picrites indicates extensive melting (23 -27%) of anomalously hot mantle (‘—1500°C), which is consistent with an origin from a mantle plume head.
    [Show full text]
  • Large Igneous Provinces and Mass Extinctions: an Update
    Downloaded from specialpapers.gsapubs.org on April 29, 2015 OLD G The Geological Society of America Special Paper 505 2014 OPEN ACCESS Large igneous provinces and mass extinctions: An update David P.G. Bond* Department of Geography, Environment and Earth Science, University of Hull, Hull HU6 7RX, UK, and Norwegian Polar Institute, Fram Centre, 9296 Tromsø, Norway Paul B. Wignall School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UK ABSTRACT The temporal link between mass extinctions and large igneous provinces is well known. Here, we examine this link by focusing on the potential climatic effects of large igneous province eruptions during several extinction crises that show the best correlation with mass volcanism: the Frasnian-Famennian (Late Devonian), Capi- tanian (Middle Permian), end-Permian, end-Triassic, and Toarcian (Early Jurassic) extinctions. It is clear that there is no direct correlation between total volume of lava and extinction magnitude because there is always suffi cient recovery time between individual eruptions to negate any cumulative effect of successive fl ood basalt erup- tions. Instead, the environmental and climatic damage must be attributed to single- pulse gas effusions. It is notable that the best-constrained examples of death-by- volcanism record the main extinction pulse at the onset of (often explosive) volcanism (e.g., the Capitanian, end-Permian, and end-Triassic examples), suggesting that the rapid injection of vast quantities of volcanic gas (CO2 and SO2) is the trigger for a truly major biotic catastrophe. Warming and marine anoxia feature in many extinc- tion scenarios, indicating that the ability of a large igneous province to induce these proximal killers (from CO2 emissions and thermogenic greenhouse gases) is the single most important factor governing its lethality.
    [Show full text]
  • Illawarra Reversal: the fingerprint of a Superplume That Triggered Pangean Breakup and the End-Guadalupian (Permian) Mass Extinction
    Gondwana Research 15 (2009) 421–432 Contents lists available at ScienceDirect Gondwana Research journal homepage: www.elsevier.com/locate/gr Illawarra Reversal: The fingerprint of a superplume that triggered Pangean breakup and the end-Guadalupian (Permian) mass extinction Yukio Isozaki Department of Earth Science and Astronomy, The University of Tokyo, Komaba, Meguro, Tokyo 153-8902, Japan article info abstract Article history: The Permian magnetostratigraphic record demonstrates that a remarkable change in geomagnetism occurred in Received 22 July 2008 the Late Guadalupian (Middle Permian; ca. 265 Ma) from the long-term stable Kiaman Reverse Superchron Received in revised form 10 December 2008 (throughout the Late Carboniferous and Early-Middle Permian) to the Permian–Triassic Mixed Superchron with Accepted 11 December 2008 frequent polarity changes (in the Late Permian and Triassic). This unique episode called the Illawarra Reversal Available online 24 December 2008 probably reflects a significant change in the geodynamo in the outer core of the planet after a 50 million years of Keywords: stable geomagnetism. The Illawarra Reversal was likely led by the appearance of a thermal instability at the – Illawarra Reversal 2900 km-deep core mantle boundary in connection with mantle superplume activity. The Illawarra Reversal Permian and the Guadalupian–Lopingian boundary event record the significant transition processes from the Paleozoic Superplume to Mesozoic–Modern world. One of the major global environmental changes in the Phanerozoic occurred Geodynamo almost simultaneously in the latest Guadalupian, as recorded in 1) mass extinction, 2) ocean redox change, 3) Mass extinction sharp isotopic excursions (C and Sr), 4) sea-level drop, and 5) plume-related volcanism.
    [Show full text]
  • Evaporite Interactions with Magma Part 3 of 3
    www.saltworkconsultants.com Salty MattersJohn Warren - Saturday April 13, 2019 Evaporite interactions with magma Part 3 of 3: On-site evaporite and major extinction events? Introduction 60 The previous two articles in this series Siberian Traps dealt with heating evaporites, vola- tiles expelled into the atmosphere, 50 and major biotal extinction events. Emeishan Traps I argued that short-term heating of 40 Deccan Traps a megaevaporite mass during em- Cental Atlantic (+ Yucatan bolide) placement of a Large Igneous Prov- 30 Magmatic Province ince (LIP) or heating of evaporities at atmosphere into volatiles the site of a large bolide impact, will 20 of evaporitic volumes Large Carribean-Columbian move vast volumes of sulphurous Generic extinctions (%) Columbia Karoo Traps and halocarbon volatiles, as well as 10 Paraná Traps River Brito-Arctic Ontong-Java solids, CO2 and CH4 into the earth's No on-site upper atmosphere (Figure 1a). The Ethiopian Traps evaporites resulting catastrophic climatic effects 0 1 2 3 4 19 20 link in time and probable causes to A. Volume of ood basalts (x 106 km3) earth-scale major extinction hori- Emeishan Traps Siberian Traps zons. (Figure 1b). In this article shall (269-265Ma) (253-250Ma) examine how three of the five major Deccan Traps CAMP, Brazil Phanerozoic extinction events have 50 3. End-Permian (67-65Ma) an evaporite association, starting with (201.5Ma) the most intense extinction event of 40 1. Late Ordovican Capitanian 5. End-Cretaceous the Phanerozoic; the end-Permian 4.Late Triassic and its link to LIP emplacement into 30 two separate sequences of massive 2.
    [Show full text]
  • Farming with Crops and Rocks to Address Global Climate, Food and Soil Security
    PERSPECTIVE https://doi.org/10.1038/s41477-018-0108-y Farming with crops and rocks to address global climate, food and soil security David J. Beerling 1*, Jonathan R. Leake 1, Stephen P. Long 2,3,4, Julie D. Scholes1, Jurriaan Ton 1, Paul N. Nelson 5, Michael Bird 5, Euripides Kantzas1, Lyla L. Taylor 1, Binoy Sarkar 1, Mike Kelland1, Evan DeLucia2,3, Ilsa Kantola2, Christoph Müller 6, Greg H. Rau7 and James Hansen8 The magnitude of future climate change could be moderated by immediately reducing the amount of CO2 entering the atmo- sphere as a result of energy generation and by adopting strategies that actively remove CO2 from it. Biogeochemical improve- ment of soils by adding crushed, fast-reacting silicate rocks to croplands is one such CO2-removal strategy. This approach has the potential to improve crop production, increase protection from pests and diseases, and restore soil fertility and struc- ture. Managed croplands worldwide are already equipped for frequent rock dust additions to soils, making rapid adoption at scale feasible, and the potential benefits could generate financial incentives for widespread adoption in the agricultural sector. However, there are still obstacles to be surmounted. Audited field-scale assessments of the efficacy of CO2 capture are urgently required together with detailed environmental monitoring. A cost-effective way to meet the rock requirements for CO2 removal must be found, possibly involving the recycling of silicate waste materials. Finally, issues of public perception, trust and accep- tance must also be addressed. ising concentrations of atmospheric CO2, and other green- needed for meeting the United Nations targets requires rapid phas- house gases (GHGs) emitted by human activities, are already ing out of fossil fuel emissions and the deployment of scalable having substantial adverse climate impacts that threaten approaches for CO2 removal (CDR) from the atmosphere with so- R 1,2 global food security .
    [Show full text]
  • Late Paleozoic Glaciation and Ice Sheet
    University of Wisconsin Milwaukee UWM Digital Commons Theses and Dissertations May 2013 Late Paleozoic Glaciation and Ice Sheet Collapse Over Western and Eastern Gondwana: Sedimentology and Stratigraphy of Glacial to Post- Glacial Strata in Western Argentina and Tasmania, Australia Lindsey C. Henry University of Wisconsin-Milwaukee Follow this and additional works at: https://dc.uwm.edu/etd Part of the Geology Commons Recommended Citation Henry, Lindsey C., "Late Paleozoic Glaciation and Ice Sheet Collapse Over Western and Eastern Gondwana: Sedimentology and Stratigraphy of Glacial to Post-Glacial Strata in Western Argentina and Tasmania, Australia" (2013). Theses and Dissertations. 112. https://dc.uwm.edu/etd/112 This Dissertation is brought to you for free and open access by UWM Digital Commons. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of UWM Digital Commons. For more information, please contact [email protected]. LATE PALEOZOIC GLACIATION AND ICE SHEET COLLAPSE OVER WESTERN AND EASTERN GONDWANA: SEDIMENTOLOGY AND STRATIGRAPHY OF GLACIAL TO POST-GLACIAL STRATA IN WESTERN ARGENTINA AND TASMANIA, AUSTRALIA by Lindsey C. Henry A Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Geosciences at The University of Wisconsin-Milwaukee May 2013 ABSTRACT LATE PALEOZOIC GLACIATION AND ICE SHEET COLLAPSE OVER WESTERN AND EASTERN GONDWANA: SEDIMENTOLOGY AND STRATIGRAPHY OF GLACIAL TO POST-GLACIAL STRATA IN WESTERN ARGENTINA AND TASMANIA, AUSTRALIA by Lindsey C. Henry The University of Wisconsin-Milwaukee, 2013 Under the supervision of Professors Margaret L. Fraiser and John L. Isbell The late Paleozoic ice age (LPIA; 345-280 million years ago) provides the last complete record of a major deglaciation on a vegetated Earth, and therefore can serve as a proxy for Earth’s inevitable transition out of its present glaciated state.
    [Show full text]
  • On the Ages of Flood Basalt Events Sur L'âge Des Trapps Basaltiques
    C. R. Geoscience 335 (2003) 113–140 Geodynamics / Géodynamique On the ages of flood basalt events Sur l’âge des trapps basaltiques Vincent E. Courtillot a,∗,PaulR.Renneb,c a Institut de physique du Globe de Paris, 4, place Jussieu, 75252 Paris cedex 05, France b Berkeley Geochronology Center, Berkeley, CA, USA c Department of Earth and Planetary Science, University of California, Berkeley, CA, USA Received 18 July 2002; accepted 22 October 2002 Written on invitation of the Editorial Board Abstract We review available data constraining the extent, volume, age and duration of all major Phanerozoic continental flood basalts (CFB or traps) and oceanic plateaus (OP), together forming the group of large igneous provinces (LIP), going from the smallest Columbia flood basalts at ∼16 Ma to the as yet ill-known remnants of a possible trap at ∼360 Ma in eastern Siberia. The 16 traps (CFB and OP) reviewed form a rather unimodal distribution with an initial modal volume of the order of 2.5 Mkm3.Most provinces agree with a rather simple first order model in which volcanism may have lasted of the order of 10 Ma, often resulting in continental break-up, but where most of the volume was erupted in about 1 Ma or sometimes less. This makes CFBs/OPs (LIPs) major geodynamic events, with fluxes exceeding the total output of present day hot spots and even possibly exceeding over short times the entire crustal production of mid-ocean ridges. The proposed correlation between trap ages and the ages of several geological events, including mass extinctions and oceanic anoxia, is found to have improved steadily as more data have become available, to the point that the list of trap ages may coincide with many major divisions in the geological time scale.
    [Show full text]
  • Large Igneous Provinces, Mantle Plumes and Metallogeny in the Earth’S History
    A.P. Vinogradov Institute of Geochemistry, Siberian Branch, Russian Academy of Sciences (IGC SB RAS) LARGE IGNEOUS PROVINCES, MANTLE PLUMES AND METALLOGENY IN THE EARTH’S HISTORY ABSTRACT VOLUME September 1–8, 2015 Irkutsk – Listvyanka, Russia IRKUTSK 2015 УДК 552.3 ББК Д342.56 К84 Large Igneous Provinces, Mantle Plumes and Metallogeny in the Earth’s History (Abstract Volume). – Irkutsk: Publishing House of V.B. Sochava institute of Geography SB RAS, 2015. – 153 p. The publication contains abstracts of international conference “Large Igneous Provinces, Mantle Plumes and Metallogeny in the Earth’s History” organized by A.P. Vinogradov Institute of Geochemistry of the Siberian Branch of the Russian Academy of Sciences (Irkutsk – Listvyanka, September 1–8, 2015). The proceeding will be interesting for geologists dealing with mafic/felsic igneous complexes and their metallogenic specialization. Compliers of the Abstract volume: Academician of RAS Mikhail I. Kuzmin PhD Vasiliy A. Belyaev PhD Yulia I. Tarasova Abstracts are published in author’s edition. International conference “Large Igneous Provinces, Mantle Plumes and Metallogeny in the Earth’s History” and publication of Abstract volume are supported by the Russian Foundation for Basic Research (Grant 15-05-20655). © The authors of abstracts, 2015 © A.P. Vinogradov Institute of Geochemistry of the Siberian Branch of the Russian Academy of Sciences ISBN 978-5-94797-252-8 2 CONTENTS Akhundjanov R., Zenkova S.O., Karimovа F.B., Saydiganiev S.S. ORE-MAGMATIC SYSTEM OF ULTRABASIC-BASIC INTRUSIONS OF THE 9 MIDDLE AND SOUTHERN TIEN-SHAN (UZBEKISTAN) Antipin V.S., Gerel О., Perepelov А.B., Odgerel D. LATE PALEOZOIC AND EARLY MESOZOIC RARE-METAL GRANITES OF 11 LARGE IGENOUS PROVINCES OF BAIKAL REGION AND MONGOLIA: COMPARATIVE GEOCHEMISTRY AND MAGMA SOURCES Ashchepkov I.V., Vladykin N.V., Spetsius Z.V., Logvinova A.M., Downes H., Ntaflos T.
    [Show full text]
  • Reply to Comment by Ali, J.R. and Wignall, P. on Ota, A. and Isozaki, Y., 2006
    Journal of Asian Earth Sciences 30 (2007) 201–203 www.elsevier.com/locate/jaes Reply to Comment by Ali, J.R. and Wignall, P. on Ota, A. and Isozaki, Y., 2006. Fusuline biotic turnover across the Guadalupian–Lopingian (Middle–Upper Permian) boundary in mid-oceanic carbonate buildups: Biostratigraphy of accreted limestone, Japan. Journal of Asian Earth Sciences 26, 353–368 Yukio Isozaki *, Ayano Ota Department of Earth Science and Astronomy, The University of Tokyo, Tokyo 153-8902, Japan Received 19 October 2006; accepted 15 November 2006 We appreciate the comment by Ali and Wignall, as it Wuchiapingian (Lower Lopingian) Wujiaping Formation provides us with an appropriate opportunity to explain in its type locality in Shaanxi (Lu, 1956; Isozaki et al., in the link between volcanism and extinction at the Guadalu- preparation), in Sichuan (Isozaki et al., 2004), and in pian–Lopingian boundary (G–LB) event that was not the Hunan (Li et al., 1991), indicating no survival of the Guad- main topic of the commented article (Ota and Isozaki, alupian fauna after the Wangpo volcanism. This unique 2006). Continental flood basalts (CFB) have often been bed is also recognized at Qingying and at Xinchang near regarded as the ultimate cause of mass extinctions on Mt. Emei(shan) in central Sichuan; above the Maokou account of their apparent chronological coincidence with Formation and below the Emeishan Traps (Fig. 1). As the extinction-related boundaries of the Phanerozoic (e.g., no other thick tuff occurs around the G–LB horizon in Courtillot, 1999; Wignall, 2001; Ernst and Buchan, 2003). South China, the Wangpo tuff represents a prime strati- For the Permo-Triassic boundary (P-TB), the Siberian graphical and chronological marker bed of the G–LB with Traps are the most popular candidate (e.g., Renne and high-precision synchronism.
    [Show full text]
  • From Flood Basalts to the Inception of Oceanization: Example from the 40Ar/39Ar High-Resolution Picture of the Karoo Large Igneous Province Fred Jourdan, G
    From flood basalts to the inception of oceanization: example from the 40Ar/39Ar high-resolution picture of the Karoo large igneous province Fred Jourdan, G. Féraud, Hervé Bertrand, M.K Watkeys To cite this version: Fred Jourdan, G. Féraud, Hervé Bertrand, M.K Watkeys. From flood basalts to the inception of oceanization: example from the 40Ar/39Ar high-resolution picture of the Karoo large igneous province. Geochemistry, Geophysics, Geosystems, AGU and the Geochemical Society, 2007, 8 (2), 20 p. 10.1029/2006GC001392. hal-00095813 HAL Id: hal-00095813 https://hal.archives-ouvertes.fr/hal-00095813 Submitted on 6 Jul 2017 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Article Geochemistry 3 Volume 8, Number 2 Geophysics 8 February 2007 Q02002, doi:10.1029/2006GC001392 GeosystemsG G ISSN: 1525-2027 AN ELECTRONIC JOURNAL OF THE EARTH SCIENCES Published by AGU and the Geochemical Society From flood basalts to the inception of oceanization: Example from the 40Ar/39Ar high-resolution picture of the Karoo large igneous province F. Jourdan UMR-CNRS 6526 Ge´osciences Azur, Universite´ de Nice-Sophia Antipolis, F-06108 Nice, France Berkeley Geochronology Center, 2455 Ridge Road, Berkeley, California 94709, USA ([email protected]) G.
    [Show full text]
  • Triggering of the Largest Deccan Eruptions by the Chicxulub Impact Mark A
    Triggering of the largest Deccan eruptions by the Chicxulub impact Mark A. Richards1,†, Walter Alvarez1,2, Stephen Self1, Leif Karlstrom3, Paul R. Renne1,4, Michael Manga1, Courtney J. Sprain,1,4 Jan Smit,2,5 Loÿc Vanderkluysen6, and Sally A. Gibson7 1 Department of Earth and Planetary Science, University of California, Berkeley, California 94720, USA 2 Osservatorio Geologico di Coldigioco, Contrada Coldigioco 4, 62021 Apiro (MC), Italy 3 Department of Geological Sciences, University of Oregon, Eugene, Oregon 97403, USA 4 Berkeley Geochronology Center, Berkeley, California 94709, USA 5 Department of Sedimentary Geology, Vrije Universeit, De Boelelaan 1085, 1081 HV Amsterdam, Netherlands 6 Department of Biodiversity, Earth and Environmental Science, Drexel University, Philadelphia, Pennsylvania 19104, USA 7 Department of Earth Sciences, University of Cambridge, Cambridge CB2 3EQ, UK † [email protected] Abstract New constraints on the timing of the Cretaceous-Paleogene mass extinction and the Chicxulub impact, together with a particularly voluminous and apparently brief eruptive pulse toward the end of the “main-stage” eruptions of the Deccan continental flood basalt province suggest that these three events may have occurred within less than about a hundred thousand years of each other. Partial melting induced by the Chicxulub event does not provide an energetically plausible explanation for this coincidence, and both geochronologic and magnetic-polarity data show that Deccan volcanism was under way well before Chicxulub/Cretaceous-Paleogene time. However, historical data document that eruptions from existing volcanic systems can be triggered by earthquakes. Seismic modeling of the ground motion due to the Chicxulub impact suggests that the impact could have generated seismic energy densities of order 0.1–1.0 J/m3 throughout the upper ∼200 km of Earth’s mantle, sufficient to trigger volcanic eruptions worldwide based upon comparison with historical examples.
    [Show full text]