20170601173846853169.Pdf

Total Page:16

File Type:pdf, Size:1020Kb

20170601173846853169.Pdf Gondwana Research 35 (2016) 40–58 Contents lists available at ScienceDirect Gondwana Research journal homepage: www.elsevier.com/locate/gr Geologic and geochemical insights into the formation of the Taiyangshan porphyry copper–molybdenum deposit, Western Qinling Orogenic Belt, China Kun-Feng Qiu a,b,⁎,RyanD.Taylorb,Yao-HuiSonga,c,Hao-ChengYua,d,Kai-RuiSonga,NanLia a State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing 100083, China b U.S. Geological Survey, Box 25046, Mail Stop 973, Denver Federal Center, Denver, CO 80225-0046, USA c Airborne Survey and Remote Sensing Center of Nuclear Industry, Shijiazhuang 050000, China d The 7th Gold Detachment of Chinese Armed Police Force, Yantai 264004, China article info abstract Article history: Taiyangshan is a poorly studied copper–molybdenum deposit located in the Triassic Western Qinling collisional Received 24 January 2016 belt of northwest China. The intrusions exposed in the vicinity of the Taiyangshan deposit record episodic Received in revised form 24 March 2016 magmatism over 20–30 million years. Pre-mineralization quartz diorite porphyries, which host some of the de- Accepted 31 March 2016 posit, were emplaced at 226.6 ± 6.2 Ma. Syn-collisional monzonite and quartz monzonite porphyries, which also Available online 2 May 2016 host mineralization, were emplaced at 218.0 ± 6.1 Ma and 215.0 ± 5.8 Ma, respectively. Mineralization occurred Handling Editor: F. Pirajno during the transition from a syn-collisional to a post-collisional setting at ca. 208 Ma. A barren post- mineralization granite porphyry marked the end of post-collisional magmatism at 200.7 ± 5.1 Ma. The ore- ε − Keywords: bearing monzonite and quartz monzonite porphyries have a Hf(t) range from 2.0 to +12.5, which is much Geochronology more variable than that of the slightly older quartz diorite porphyries, with TDM2 of 1.15–1.23 Ga corresponding Geochemistry to the positive εHf(t) values and TDM1 of 0.62–0.90 Ga corresponding to the negative εHf(t) values. Molybdenite in Taiyangshan deposit the Taiyangshan deposit with 27.70 to 38.43 ppm Re suggests metal sourced from a mantle–crust mixture or – Porphyry copper molybdenum from mafic and ultramafic rocks in the lower crust. The δ34S values obtained for pyrite, chalcopyrite, and molyb- Western Qinling Orogenic Belt denite from the deposit range from +1.3‰ to +4.0‰, +0.2‰ to +1.1‰,and+5.3‰ to +5.9‰,respectively, 18 suggesting a magmatic source for the sulfur. Calculated δ Ofluid values for magmatic K-feldspar from porphyries (+13.3‰), hydrothermal K-feldspar from stockwork veins related to potassic alteration (+11.6‰), and hydro- thermal sericite from quartz–pyrite veins (+8.6 to +10.6‰) indicate the Taiyangshan deposit formed domi- nantly from magmatic water. Hydrogen isotope values for hydrothermal sericite ranging from −85 to −50‰ may indicate that magma degassing progressively depleted residual liquid in deuterium during the life of the magmatic–hydrothermal system. Alternatively, δD variability may have been caused by a minor amount of mixing with meteoric waters. We propose that the ore-related magma was derived from partial melting of the ancient Mesoproterozoic to Neoproterozoic middle to lower continental crust. This crust was likely metasomatized during earlier subduction, and the crustal magmas may have been contaminated with litho- spheric mantle derived magma triggered by MASH (e.g., melting, assimilation, storage, and homogenization) processes during collisional orogeny. In addition, a significant proportion of the metals and sulfur supplied from mafic magma were simultaneously incorporated into the resultant hybrid magmas. © 2016 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved. 1. Introduction origin of porphyry deposits abound, but broadly form in two distinct tec- tonic settings (e.g., Richards, 2003; Hou et al., 2009; Pirajno and Zhou, Porphyry deposits are some of the world's most important reposito- 2015). Commonly these deposits occur in continental margin and ries of copper, gold, and molybdenum. They are defined as large volumes island-arc settings (Sillitoe, 1972; Cooke et al., 2005; Sillitoe, 2010; of hydrothermally altered rock centered on porphyry stocks, and are pre- Richards, 2011). In continental arc setting, such as in the Andes, flattening dominantly related to oxidized, felsic to intermediate calc-alkaline of a subducting oceanic slab, and associated crustal thickening and uplift magmas (Richards, 2003; Sillitoe, 2010; Lee, 2014). Hypotheses for the has been proposed to be essential for ore formation (Skewes and Stern, 1995; Cooke et al., 2005). In island-arc settings, such as throughout the western Pacific, porphyry deposits are associated with arc-parallel ⁎ Corresponding author at: State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing 100083, China. strike-slip faults and arc-transverse faults that are related to tearing of E-mail addresses: [email protected] (K.-F. Qiu), [email protected] (N. Li). the subducting slab (Richards, 2003). Alternatively, some porphyry Cu http://dx.doi.org/10.1016/j.gr.2016.03.014 1342-937X/© 2016 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved. K.-F. Qiu et al. / Gondwana Research 35 (2016) 40–58 41 (Mo–Au) deposits may form during the post-subduction collisional pro- mafic rocks, or lower crustal arc plutons and cumulates (e.g., Hou et al., cess, as observed in the Himalayan–Tibetan orogen (e.g., Hou et al., 2004; 2004; Shafiei et al., 2009; Lu et al., 2013; Chiaradia, 2014; Z.M. Yang Hou et al., 2009; Shafiei et al., 2009; Hou et al., 2013; Deng et al., 2014a; et al., 2014b, 2015d; Qiu et al., 2016); or (3) asthenosphere upwelling Hou et al., 2015; Lu et al., 2015; Z.M. Yang et al., 2015d, 2016), the in response to delamination, slab breakoff, back-arc extension, or oro- Qinling–DabieorogeninChina(e.g.,Li et al., 2013; Chen and Santosh, genic collapse (e.g., Jiang et al., 2006; Mair et al., 2011; Wang et al., 2014; Mao et al., 2014), the Zagros orogen in Iran (e.g., Singer et al., 2016). Although it is well acknowledged that a fertilized lithospheric or- 2005; Zarasvandi et al., 2005, 2007; Shafiei et al., 2009), and the Variscan igin is necessary for porphyry deposit formation due to the absence of a orogen of western and central Europe (e.g., Seltmann and Faragher, 1994). subduction-enriched asthenospheric mantle source (Chiaradia, 2014; The formation processes of ore-bearing porphyries in arc settings are Richards, 2014), some key problems on potential lithospheric source re- well understood and are acknowledged to be closely associated with gions are still elusive, which hampers our understanding of the genesis a subducting oceanic slab (e.g., Cooke et al., 2005; Sillitoe, 2010; of collisional porphyry systems and their targeting for exploration. Richards, 2014; Pirajno, 2016). However, post-subduction collisional The Western Qinling Orogenic Belt is a typical collisional orogen, and metallogeny is more complex and may involve a number of different was assembled by collision between the North China and South China processes and (or) magma, metal, and fluid sources. Potential broad- Blocks during the Late Triassic (Fig. 1; Chen and Santosh, 2014; Deng scale ore-forming processes include melting of: (1) orogenically thick- and Wang, 2015; Dong and Santosh, 2016). It hosts a belt of porphyry ened crust (e.g., Richards, 2009; Li et al., 2011; Xu et al., 2013; Deng deposits and occurrences that can be divided into five districts et al., 2014b); (2) previously subduction-modified lithosphere, includ- (i.e., Jiangligou-Nianmuer, Xiahe-Hezuo, Tiegou-Xingshigou, Hezuo- ing metasomatized mantle, juvenile lower crust formed by underplated Dewulu, and Wenquan-Huomaidi) (Fig. 1B; Table 1; GSBGME, 1979; Fig. 1. Generalized geological map of northwestern China (modified after Dong et al., 2011; Yang et al., 2015a), also showing the location and regional geology of the Western Qinling Orogenic Belt. (A) Tectonic subdivision of China, showing the location of the Western Qinling. (B) Regional geology with emphasis of Mesozoic granitoid distribution and five main mineral districts in the Western Qinling. See Table 1 for detailed information and data sources. Abbreviation: NCB = North China Block, SCB = South China Block, BK = Bikou Terrane, NQLOB = North Qilian Orogenic Belt, NQB = North Qinling Block, SQB = South Qinling Block, SP-GZOB = Songpan-Garzê Orogenic Belt, SZ1 = Wushan-Tianshui-Shangdan suture zone, SZ2 = Maqu-Nanping-Lueyang suture zone, TLF = Tan-Lu Fault, F1 = Baoji-Gouyuan Fault, F2 = Xinyang-Yuanlong (Baoji-Tianshui) Fault, F3 = Hezuo-Minxian-Dangchuan Fault, F4 = Diebu-Bailongjiang Fault, F5 = Lixian-Luojiapu Fault, F6 = Chengxian-Taibaishan Fault, F7 = Xihe Fault, F8 = Wudu Fault, F9 = Minjiang Fault, F10 = Pingwu-Qingchuan Fault. 42 K.-F. Qiu et al. / Gondwana Research 35 (2016) 40–58 Table 1 Summary of porphyry–skarn deposits in the five mineral districts in the Western Qinling, with geochronological data of mineralization and related granitoids. Mineral deposit Type Metal Tonnage Location Age (Ma) Mineral and method Reference Jiangligou-Nianmuer mineral district Xiekeng S Cu–Au Medium Xunhua, Qinghai 218 ± 2 Zircon LA-ICPMS U–Pb Sun et al. (2013), Guo et al. (2012), Zhang et al. (2006) Jiangligou P–SCu–Mo–W Medium Tongren, Qinghai 214 Molybdenite Re–Os He (2012), Li et al. (2010); Dong et al. (2010) Shuangpengxi P–SCu–Au Medium Tongren, Qinghai No data J. Zhang et al. (2014a), T. Zhang et al. (2014b), He (2012) Gangcha P–S Cu Prospect Tongren, Qinghai No data GSBGME (1979), J. Zhang et al. (2014a), T. Zhang et al. (2014b) Xiechangzhigou P–S Cu Prospect Tongren, Qinghai No data GSBGME (1979), Yin (2007) Langmujia P–S Cu Prospect Tongren, Qinghai No data Yin et al. (2005) Hongqika P–SCu–Au Prospect Tongren, Qinghai No data GSBGME (1979), Yin et al.
Recommended publications
  • Two Contrasting Phanerozoic Orogenic Systems Revealed by Hafnium Isotope Data William J
    ARTICLES PUBLISHED ONLINE: 17 APRIL 2011 | DOI: 10.1038/NGEO1127 Two contrasting Phanerozoic orogenic systems revealed by hafnium isotope data William J. Collins1*(, Elena A. Belousova2, Anthony I. S. Kemp1 and J. Brendan Murphy3 Two fundamentally different orogenic systems have existed on Earth throughout the Phanerozoic. Circum-Pacific accretionary orogens are the external orogenic system formed around the Pacific rim, where oceanic lithosphere semicontinuously subducts beneath continental lithosphere. In contrast, the internal orogenic system is found in Europe and Asia as the collage of collisional mountain belts, formed during the collision between continental crustal fragments. External orogenic systems form at the boundary of large underlying mantle convection cells, whereas internal orogens form within one supercell. Here we present a compilation of hafnium isotope data from zircon minerals collected from orogens worldwide. We find that the range of hafnium isotope signatures for the external orogenic system narrows and trends towards more radiogenic compositions since 550 Myr ago. By contrast, the range of signatures from the internal orogenic system broadens since 550 Myr ago. We suggest that for the external system, the lower crust and lithospheric mantle beneath the overriding continent is removed during subduction and replaced by newly formed crust, which generates the radiogenic hafnium signature when remelted. For the internal orogenic system, the lower crust and lithospheric mantle is instead eventually replaced by more continental lithosphere from a collided continental fragment. Our suggested model provides a simple basis for unravelling the global geodynamic evolution of the ancient Earth. resent-day orogens of contrasting character can be reduced to which probably began by the Early Ordovician12, and the Early two types on Earth, dominantly accretionary or dominantly Paleozoic accretionary orogens in the easternmost Altaids of Pcollisional, because only the latter are associated with Wilson Asia13.
    [Show full text]
  • View / Download 7.3 Mb
    Between Shanghai and Mecca: Diaspora and Diplomacy of Chinese Muslims in the Twentieth Century by Janice Hyeju Jeong Department of History Duke University Date:_______________________ Approved: ___________________________ Engseng Ho, Advisor ___________________________ Prasenjit Duara, Advisor ___________________________ Nicole Barnes ___________________________ Adam Mestyan ___________________________ Cemil Aydin Dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of History in the Graduate School of Duke University 2019 ABSTRACT Between Shanghai and Mecca: Diaspora and Diplomacy of Chinese Muslims in the Twentieth Century by Janice Hyeju Jeong Department of History Duke University Date:_______________________ Approved: ___________________________ Engseng Ho, Advisor ___________________________ Prasenjit Duara, Advisor ___________________________ Nicole Barnes ___________________________ Adam Mestyan ___________________________ Cemil Aydin An abstract of a dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy, in the Department of History in the Graduate School of Duke University 2019 Copyright by Janice Hyeju Jeong 2019 Abstract While China’s recent Belt and the Road Initiative and its expansion across Eurasia is garnering public and scholarly attention, this dissertation recasts the space of Eurasia as one connected through historic Islamic networks between Mecca and China. Specifically, I show that eruptions of
    [Show full text]
  • M6.9 Southern Qinghai, China Earthquake of 13 April 2010 Network
    U.S. DEPARTMENT OF THE INTERIOR EARTHQUAKE SUMMARY MAP XXX U.S. GEOLOGICAL SURVEY Prepared in cooperation with the Global Seismographic M6.9 Southern Qinghai, China Earthquake of 13 April 2010 Network Epicentral Region L. B Tectonic Setting alka 90° 92° 94° 96° 98° 100° 102° 104° 106° 70° sh 80° 90° 100° 110° 120° M O N G O L I A GOLMUD Shymkent Changchun Jilin Xinjiang Minhe Dzhambul Almaty 36° QABQA 2001 Urumqi LANZHOU Tashkent Bishkek 36° NamanganK ATE Fushun Y R T i a PL Gulistan G Y n S h a n MUR Kanggye Southern Qinghai Ningxia Z S T A 40° Andizhan A N Shenyang Osh Hamhung K U N L U N Fergana 40° F A U L T Anshan Sinuiju 13 April 2010 23:49:37 UTC Pingliang T Linxia A J Kashi T H Jingning I K I Huhot P'yongyang O R ZIKETAN Neiguanying S T N E A A N Baotou Beijing O R Dalian K 1937 Lintao 33.271° N., 96.629° E. Kulob Tangshan Maying Lung- EUR Kaesong Kagang Depth 10 km AS EXPLANATION shan- IA P H LA l t Tianjin U T Mw = 6.9 (USGS) TE a u Inch`on S O A chen h F R E Ta g Shijiazhuang K O Longxi y n Yinchuan Taiyuan Mag ≥ 7.0 Hezuo K A l t E Felt across the mountaiQnionuasn area in western China, over 400 u AT e PL killed, tens of thousands displaced. n H SIA Gangu RA j Eg U W 0 - 69 km u s n O i n a L TIANSHUI n t a Xining u L H u n Y E Gansu Rawalpindi M o K u n H A l u n F S E 70 - 299 Min Xian Tianshui Islamabad a u l t Lanzhou DAWU I Luoyang Zhengzhou 34° Li Xian M Xi'an 300 - 600 Qinghai Amritsar A C H I N A Tewo 34° Faisalabad TIBETAN PLATEAU Nanjing Volcanoes Lahore g Shanghai Hui-Xian Simla L Hefei in 30° Chandigarh a J A g
    [Show full text]
  • Studies on the Diversity of Ciliate Species in Gahai Alpine Wetland of the Qinghai-Tibetan Plateau, China
    COMMUNITY ECOLOGY 20(1): 83-92, 2019 1585-8553 © AKADÉMIAI KIADÓ, BUDAPEST DOI: 10.1556/168.2019.20.1.9 Studies on the diversity of ciliate species in Gahai Alpine Wetland of the Qinghai-Tibetan Plateau, China H. C. Liu1,2, X. J. Pu1, J. Liu1 and W. H. Du1,3 1 College of Grass Science of Gansu Agricultural University, Lanzhou, Gansu Province 730070 China 2 Department of Chemistry and Life Science of Gansu Normal University for Nationalities, Hezuo, Gansu Province 747000 China 3 Correspondence to Du Wen-hua, [email protected], Present address: No. 1, Yingmen village, Anning District, Lanzhou, Gansu province, China Keywords: Ciliate, Community structure, Distribution, Functional-trophic group, Gahai Alpine Wetland of Qinghai-Tibetan Plateau, Species diversity. Abstract: This study investigated the community structure of ciliates in Gahai Alpine Wetland of Qinghai-Tibetan Plateau, China. We hypothesized that the ciliate community in the Plateau is more complex and the species diversity is richer than those in other climate zones of China. In particular, we studied how the ciliate species responded to environmental temperature, soil moisture content and the manner of pasture utilization. We determined key features of the ciliate communities such as trophic functional groups, ciliate seasonal distribution, species diversity and similarity index at six sample sites from January 2015 to October 2016. To count and characterize ciliates, we combined the non-flooded Petri dish method with in vivo observation and silver staining. We identified 162 ciliate species in this area, showing a high species and functional diversity. The mode of nutri- tion was diverse, with the lowest number of ciliates in group N (Nonselective omnivores, 4 species) and the highest number in group B (Bacterivores-detritivores, 118 species, corresponding to 73% of the total species number).
    [Show full text]
  • Wilson Cycle Guide
    Wilson Cycle Description Lynn S. Fichter and Eric Pyle Department of Geology and Environmental Science James Madison University Layout of this Guide For each stage represented in this Wilson Cycle, several pieces of information are provided: Description of Process: a description of the forces acting on a particular location, and the results of those forces; Composition: the particular rock types that result from these forces, including chemical make up, major minerals present, and texture (grain size and orientation), expressed in photographs, verbal descriptions, and categorical graphs; Specific Locations, Present and Past: the map locations of examples of the environment, with current and past locations represented. Stage A: Stable Continental Craton Description of Process: This stage represents the basis of all existing continents, showing in a simplified fashion both continental crust and adjacent oceanic crust, both of which lie over the mantle. You will notice that the continental crust is considerably thicker than the ocean crust. Continental crust is less dense than oceanic crust (approximately 2.7 g/cm3 vs. 3.3 g/cm3), and so “rides” higher over the mantle. Continental crust is also more rigid that oceanic crust. Furthermore, the development of continental crust involves considerable thickening. Composition: This diagram represents considerable simplification, in that the internal structure has not been shown, but is represented as a crystalline “basement” for the continent. This basement material represents a variety of rock types, including granites and diorites, gneisses and schists, and various sedimentary rocks. Taken as a whole, the average composition of the basement rock is the same as a granodiorite – enriched in sodium, potassium and silica-rich minerals, such as alkali feldspar, sodium plagioclase, and quartz, and depleted in iron/magnesium, silica poor minerals, such as olivine, pyroxene, and amphibole.
    [Show full text]
  • China's Strategic Modernization: Implications for the United States
    CHINA’S STRATEGIC MODERNIZATION: IMPLICATIONS FOR THE UNITED STATES Mark A. Stokes September 1999 ***** The views expressed in this report are those of the author and do not necessarily reflect the official policy or position of the Department of the Army, the Department of the Air Force, the Department of Defense, or the U.S. Government. This report is cleared for public release; distribution is unlimited. ***** Comments pertaining to this report are invited and should be forwarded to: Director, Strategic Studies Institute, U.S. Army War College, 122 Forbes Ave., Carlisle, PA 17013-5244. Copies of this report may be obtained from the Publications and Production Office by calling commercial (717) 245-4133, FAX (717) 245-3820, or via the Internet at [email protected] ***** Selected 1993, 1994, and all later Strategic Studies Institute (SSI) monographs are available on the SSI Homepage for electronic dissemination. SSI’s Homepage address is: http://carlisle-www.army. mil/usassi/welcome.htm ***** The Strategic Studies Institute publishes a monthly e-mail newsletter to update the national security community on the research of our analysts, recent and forthcoming publications, and upcoming conferences sponsored by the Institute. Each newsletter also provides a strategic commentary by one of our research analysts. If you are interested in receiving this newsletter, please let us know by e-mail at [email protected] or by calling (717) 245-3133. ISBN 1-58487-004-4 ii CONTENTS Foreword .......................................v 1. Introduction ...................................1 2. Foundations of Strategic Modernization ............5 3. China’s Quest for Information Dominance ......... 25 4.
    [Show full text]
  • Genetic Signatures of High-Altitude Adaptation and Geographic
    www.nature.com/scientificreports OPEN Genetic signatures of high‑altitude adaptation and geographic distribution in Tibetan sheep Jianbin Liu1,2*, Chao Yuan1,2, Tingting Guo1,2, Fan Wang3, Yufeng Zeng1, Xuezhi Ding1, Zengkui Lu1,2, Dingkao Renqing4, Hao Zhang5, Xilan Xu6, Yaojing Yue1,2, Xiaoping Sun1,2, Chune Niu1,2, Deqing Zhuoga7* & Bohui Yang1,2* Most sheep breeding programs designed for the tropics and sub‑tropics have to take into account the impacts of environmental adaptive traits. However, the genetic mechanism regulating the multiple biological processes driving adaptive responses remains unclear. In this study, we applied a selective sweep analysis by combing 1% top values of Fst and ZHp on both altitude and geographic subpopulations (APS) in 636 indigenous Tibetan sheep breeds. Results show that 37 genes were identifed within overlapped genomic regions regarding Fst signifcantly associated with APS. Out of the 37 genes, we found that 8, 3 and 6 genes at chromosomes (chr.) 13, 23 and 27, respectively, were identifed in the genomic regions with 1% top values of ZHp. We further analyzed the INDEL variation of 6 genes at chr.27 (X chromosome) in APS together with corresponding orthologs of 6 genes in Capra, Pantholops, and Bos Taurus. We found that an INDEL was located within 5′UTR region of HAG1 gene. This INDEL of HAG1 was strongly associated with the variation of APS, which was further confrmed by qPCR. Sheep breeds carrying “C‑INDEL” of HAG1 have signifcantly greater body weight, shear amount, corpuscular hemoglobin and globulin levels, but lower body height, than those carrying “CA‑INDEL” of HAG1.
    [Show full text]
  • This Article Appeared in a Journal Published by Elsevier. the Attached
    This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier’s archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright Author's personal copy Resources, Conservation and Recycling 54 (2010) 1296–1302 Contents lists available at ScienceDirect Resources, Conservation and Recycling journal homepage: www.elsevier.com/locate/resconrec Survey of officials’ awareness on circular economy development in China: Based on municipal and county level Bing Xue a,b,1,2, Xing-peng Chen b,∗,2, Yong Geng a,1, Xiao-jia Guo b,2, Cheng-peng Lu b,2, Zi-long Zhang b,d,2, Chen-yu Lu c,b,2,3 a Circular Economy and Industrial Ecology Group, Institute of Applied Ecology, Chinese Academy of Sciences, No. 72, Wenhua Road, Shenhe District, 110016 Shenyang, China b Institute of Human Geography, College of Earth and Environmental Sciences, Lanzhou University, No. 222, South Tianshui Road, Chenguan District, 730000 Lanzhou, China c College of Geography and Environment Science, Northwest Normal University, No. 967, Anning East Road, Anning District, 730070 Lanzhou, China d Gund Institute for Ecological Economics, The University of Vermont, 617 Main Street, Burlington, VT 05405, USA article info abstract Article history: With rapid industrialization in China, both resource scarcity and resources efficiency have challenged the Received 23 December 2009 country’s sustainable development.
    [Show full text]
  • Connecting the Deep Earth and the Atmosphere
    In Mantle Convection and Surface Expression (Cottaar, S. et al., eds.) AGU Monograph 2020 (in press) Connecting the Deep Earth and the Atmosphere Trond H. Torsvik1,2, Henrik H. Svensen1, Bernhard Steinberger3,1, Dana L. Royer4, Dougal A. Jerram1,5,6, Morgan T. Jones1 & Mathew Domeier1 1Centre for Earth Evolution and Dynamics (CEED), University of Oslo, 0315 Oslo, Norway; 2School of Geosciences, University of Witwatersrand, Johannesburg 2050, South Africa; 3Helmholtz Centre Potsdam, GFZ, Telegrafenberg, 14473 Potsdam, Germany; 4Department of Earth and Environmental Sciences, Wesleyan University, Middletown, Connecticut 06459, USA; 5DougalEARTH Ltd.1, Solihull, UK; 6Visiting Fellow, Earth, Environmental and Biological Sciences, Queensland University of Technology, Brisbane, Queensland, Australia. Abstract Most hotspots, kimberlites, and large igneous provinces (LIPs) are sourced by plumes that rise from the margins of two large low shear-wave velocity provinces in the lowermost mantle. These thermochemical provinces have likely been quasi-stable for hundreds of millions, perhaps billions of years, and plume heads rise through the mantle in about 30 Myr or less. LIPs provide a direct link between the deep Earth and the atmosphere but environmental consequences depend on both their volumes and the composition of the crustal rocks they are emplaced through. LIP activity can alter the plate tectonic setting by creating and modifying plate boundaries and hence changing the paleogeography and its long-term forcing on climate. Extensive blankets of LIP-lava on the Earth’s surface can also enhance silicate weathering and potentially lead to CO2 drawdown (cooling), but we find no clear relationship between LIPs and post-emplacement variation in atmospheric CO2 proxies on very long (>10 Myrs) time- scales.
    [Show full text]
  • Proterozoic First-Order Sedimentary Sequences of the Sao Francisco
    Marine and Petroleum Geology 33 (2012) 127e139 Contents lists available at SciVerse ScienceDirect Marine and Petroleum Geology journal homepage: www.elsevier.com/locate/marpetgeo Proterozoic first-order sedimentary sequences of the São Francisco craton, eastern Brazil Fernando F. Alkmima,*, Marcelo A. Martins-Netob a Departamento de Geologia, Escola de Minas, Universidade Federal de Ouro Preto, Morro do Cruzeiro, 35.400.000 Ouro Preto, MG, Brazil b Vicenza Mineração, Av. Agulhas Negras, 580, Mangabeiras, 30210-340 Belo Horizonte, MG, Brazil article info abstract Article history: The São Francisco craton in eastern Brazil hosts sedimentary sequences deposited between the Paleo- Received 4 May 2010 archean (w3300 Ma) and Late Neoproterozoic (w580 Ma). Proterozoic successions occurring in this Received in revised form region comprise five 1st-order sedimentary sequences, which besides episodes of global significance 15 August 2011 record major basin-forming events. The ca. 8000 m-thick Minas-Itacolomi 1st-order sequence, exposed Accepted 18 August 2011 in the Brazilian mining district of the Quadrilátero Ferrífero and containing as marker bed the Lake Available online 5 September 2011 Superior-type Cauê Banded Iron Formation, tracks the operation of a Wilson cycle in the Paleoproterozoic Era. The quartz-arenite dominated Espinhaço I and II sequences record at least two major rift-sag basin- Keywords: First-order sequences forming events, which affected the host continent of the São Francisco craton at around 1.75 Ga and Proterozoic 1.57 Ga. The Macaúbas sequence and its correlatives in the extracratonic domains witness the individ- São Francisco craton ualization of a São Francisco-Congo plate in synchronicity with the break-up of Rodinia in the Cryogenian Brazil period.
    [Show full text]
  • Uprising in Tibet 10 March-30 April 2008
    Uprising in Tibet 10 March-30 April 2008 CITIES AND COUNTIES WHERE PROTESTS DOCUMENTED BY TIBET WATCH OCCURRED Lanzhou Rebkong Tsigor Thang Labrang Mangra Tsoe Luchu Machu Dzoge Marthang Ngaba Serthar Kandze Drango Tawu Bathang Lhasa 28 CHARLES SQUARE, LONDON, N1 6HT, U.K. PHONE: +44 (0)20 7324 4608 FAX: +44 (0)20 7324 4606 INTRODUCTION This report is a summary of information gathered and received by Tibet Watch concerning protests in Tibet which occurred during March and April 2008. It is not a comprehensive record of all the protests that took place in Tibet, but only of those incidents which Tibet Watch has received reliable information about. Indeed, it is likely that there were many incidents of protest across Tibet which have remain unreported due to the tight security restrictions and communications lockdown imposed. It is for the same reason that it has since been extremely difficult to find out any further information about the documented events other than what is provided here. Although some of the information in this document relies on single sources, the news we have received has, where possible, been corroborated or checked against information received by other news gathering organizations. CONTENTS Kandze Tibetan Autonomous Prefecture ................................................................................................ 3 Bathang County (Ch: Batang) .............................................................................................. 3 Drango County (Ch: Luhuo) ................................................................................................
    [Show full text]
  • Geographical and Structural Constraints of Regional Development in Western China: a Study of Gansu Province
    Issues & Studies© 42, no. 2 (June 2006): 131-170. Geographical and Structural Constraints of Regional Development in Western China: A Study of Gansu Province YEHUA DENNIS WEI AND CHUANGLIN FANG* There have been heated debates over the extent, causal mechanisms, and consequences of regional inequality in China and the proper policy in- tervention. The central government considers struggling poorer regions and the widening coastal-interior gap as serious threats to China's pros- perity, stability, and unity, and has launched the Great Western Develop- ment Strategy. Given the massive scale of the region and its tremendous diversity, more work is needed on regional development in interior China and on how effective the Chinese government has been in developing its western region. This paper broadens the study of regional inequality in YEHUA DENNIS WEI (魏也華) is Associate Professor in the Department of Geography and Urban Studies Program, University of Wisconsin at Milwaukee (UWM). Author of Re- gional Development in China: States, Globalization, and Inequality (2000), and more than forty referred journal articles, he is the recipient of the UWM Excellence in Research Award (2003), the Outstanding Young Investigator Award of the Natural Science Foundation of China (2004), and the Distinguished Scholar Award of the Regional Development and Planning Specialty Group of the Association of American Geographers (2006). He can be reached at <[email protected]>. CHUANGLIN FANG (方創琳) is Professor at the Institute of Geographical Sciences and Nat- ural Resources Research, Chinese Academy of Sciences, Beijing. He can be reached at <[email protected]>. *The authors would like to acknowledge the funding of the Chinese Academy of Sciences K.C.
    [Show full text]