DOCSLIB.ORG

Petrological Study of Spinel Peridotites of Nidar Ophiolite, Ladakh Himalaya, India

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Petrological Study of Spinel Peridotites of Nidar Ophiolite, Ladakh Himalaya, India J. Earth Syst. Sci. (2020) 129 47 Ó Indian Academy of Sciences https://doi.org/10.1007/s12040-019-1308-1 (0123456789().,-volV)(0123456789().,-volV) Petrological study of spinel peridotites of Nidar ophiolite, Ladakh Himalaya, India 1,2, 3 RANJIT NAYAK * and BIDYANANDA MAIBAM 1 Department of Earth and Atmospheric Sciences, NIT Rourkela, Rourkela 769 008, India. 2 Department of Geology, Addis Ababa Science and Technology University, Addis Ababa, Ethiopia. 3 Department of Earth Sciences, Manipur University, Canchipur, Imphal 795 003, India. *Corresponding author. e-mail: [email protected] MS received 12 March 2019; revised 24 September 2019; accepted 9 October 2019 Petrological study of the ultramaBc rocks from the Nidar Ophiolite Complex (NOC) of the Indus Suture Zone is carried out. The study of Cr-spinels along with olivine and pyroxenes emphasizes the genesis and tectonic setting of the ultramaBtes. Olivine from the harzburgite is Mg-rich, with the molar ratio Mg# [Mg/(Mg + Fe2+)] varying between 0.91 and 0.94 and olivine in dunite between 0.92 and 0.94. Clinopyroxene from the harzburgite is TiO2 and Na2O-poor diopside (Wo47–50En47–50Fs2–4). Spinel in harzburgite shows wide Cr#, molar ratio varied between 0.26 and 0.72, and significantly higher in dunites with Cr# ranges from 0.69–0.85. Cr# of the peridotite spinel follow a depletion trend. Calculated equilibrium conditions of the samples are 800–900°C temperature, 32 and 40 kbar pressure, oxygen fugacity À0.09 to 0.55 log units above the FMQ buAer. Residual nature of the harzburgites and the presence of high and low Cr# spinels may be due to the genetic artifact of the different ultramaBc units. Keywords. Spinel peridotites; Nidar Ophiolite Complex (NOC); supra-subduction zone (SSZ); partial melting. 1. Introduction petrological information of the upper mantle. Phase composition of the ophiolitic mantle ultra- The ophiolitic complexes of the world provide us maBc rocks is dependent on the degree and condi- vital clues in understanding magmatic and tectonic tions of partial melting and the eAects of process for the formation of oceanic lithosphere magma–rock interactions (Uysal et al. 2012). Well (Ahmed et al. 2005) and their emplacement on the preserved and fresh peridotite sequence in ophiolite margins of continental lithosphere. Ophiolite gen- complexes, can be a good source to examine the esis is in a variety of tectonic settings, either at the compositional variations and chemical geodynam- suprasubduction zone (SSZ) or mid-ocean ridge ics of upper mantle. (MOR) settings, as shown by refractory mantle The Indus Suture Zone (ISZ) are the remnants of character and Cr-rich spinel in peridotites (Pearce the Neo Tethyan ocean which closed during the et al. 1981; Dick and Bullen 1984). Peridotites are Early Cretaceous (110–130 Ma: Maheo et al. 2004: the most abundant rock type in ophiolitic com- cooling ages; *120–110 Ma: Pudsey 1986). It was plexes and are the key sources of geochemical and followed by obduction in Late Cretaceous in Supplementary materials pertaining to this article are available on the Journal of Earth Science Website (http://www.ias.ac.in/ Journals/Journal˙of˙Earth˙System˙Science). 47 Page 2 of 15 J. Earth Syst. Sci. (2020) 129 47 Kohistan–Ladakh terranes (Searle et al. 1999)asthe well exposed from Nidar village to Kyun Tso, the Indian plate wandered towards the Asian plate total thickness of the whole sequence is about 12 (Ahmed et al. 2008). An island arc origin was infer- km. The ophiolite complex can be divided into red by Thakur and Bhatt (1983) for the volcanic three main units from north to south. The ultra- sequence but Ahmed et al.(2008)proposedthatthe maBc unit is the basal unit of about 8–10 km in maBc unit of Nidar Ophiolite Complex (NOC) is thickness (Sachan 2001), gabbros in the middle and intra-oceanic arc magmatism. Previous studies at the top are the volcanic rocks consisting of (Sachan 2001;SiddaiahandMasuda2001) sug- sheeted dykes and volcanogenic sediments with gested that the formation of NOC is in a supra chert (Ravikant et al. 2004; Das et al. 2015). subduction zone environment. NOC is a well- Dunite, peridotite (harzburgite and lherzolite) and exposed Indus Suture Zone Ophiolite complex. The pyroxenite veins form the ultramaBcunit.Harzbur- occurrence of high-pressure mineral like clinoen- gite is the dominant peridotite. The samples have statite, coesite shows that the peridotites were undergone varying degrees of serpentinization. Dunite formed in the mantle transition zone (Das et al. is associated with the harzburgite and occurs as len- 2015). Diamond inclusions were also reported within soidal bodies at few places. The peridotites from NOC enstatite and olivine from peridotites of ISZ ophio- is cutting across by discordant dunite sequences in lite indicating the origin of peridotites at much great some places and peridotites are also encountered in the depth (*410 km) (Das et al. 2017). The ultramaBc Beld within the channelized dunite (Siddaiah 2001; rocks of the Nidar ophiolites are remarkably fresh, Sachan and Mukherjee 2003;Daset al. 2015). The and the relict primary minerals could be used to infer basal dunite body host podiform chromitite of about the original characteristics. In the present study, we 1–1.5 m thick and thin bends of chromitite (Sachan have analyzed primary silicate mineral phases of and Mukherjee 2003;Sachanet al. 2007). Pyroxenite mantle rocks of the Nidar ophiolite to Bnd out the veins are present in dunite and harzburgite as sills and equilibrium condition and related intensive param- dykes (Sachan 2001). The gabbroic unit of NOC shows eter of the mantle-sequence. The study is expected to variations from Bne grain to coarse grain without any give insights into the mantle processes (such as compositional layering. Pillow lava displays a con- partial melting and metasomatism) as well as the cordant association with the gabbros of the sequence tectonic setting of the Nidar ophiolite. and it is superimposed by volcano-sedimentary unit comprising basaltic to andesitic Cows. The lower stratigraphic part of the topmost unit has pillow lavas 2. Geology of the area and it consists of volcanogenic derived intercalated sediments like conglomerates, shale, chert, siltstone The ISZ is one of the main tectonic units of the and jasperite (Sharma and Gupta 1982). northern Himalayas, covering nearly 2500 km from Main Mantle Thrust at Pakistan (Tahirkheli et al. 1979; Ahmed et al. 2008) in the west to the Lhasa 3. Sampling and Beld observations block in the east (Le Fort 1975; Molnar and Tap- ponnier 1975). The sedimentary and ophiolite Fresh samples of harzburgite and dunite were sequences are the remnants of the Neo-Tethys collected along the Nidar valley to Kyun Tso. In seaCoor (Thakur and Mishra 1984; Ahmed et al. the study area, the dominant lithology is massive 2008). NOC is a block, thrust over the Indus Group and partially serpentinized harzburgites (*60%), and Ladakh batholith (Bgure 1) to the north and it followed by dunite (*20%), lherzolite (*5%) and has a thrust contact with the Zildat ophiolite pyroxenite veins. Undeformed coarse-grained melange in the south (Maheo et al. 2004). Further pyroxenite dykes (Bgure 2a) and dunite veins south the Zildat ophiolite melange has a thrust crosscut the harzburgite (Bgure 2b) at a few places. contact with the Tso Morari Crystalline Complex Channelized networks of dunite trending NE–SW bearing ultra-high pressure minerals (Mukherjee with disseminated chromite are also encountered et al. 2003). The general trend of Zildat ophiolite (Bgure 2c). The basal part of the mantle section is melange is NW-SE, sandwiched between Tso- marked by the presence of spinel-bearing dunite Morari Crystalline in the south and the NOC in the with moderate serpentinization (Das et al. 2015). north (Sen et al. 2013). It consists of serpentine, Here, we attempt to illustrate the petrogenetic gabbro, chert, exotic blocks of limestone and clasts processes that could explain the peridotite–dunite of blueschists. The sequences of Nidar ophiolite are association in the studied area. J. Earth Syst. Sci. (2020) 129 47 Page 3 of 15 47 Figure 1. SimpliBed geological map of Nidar Ophiolite Complex (after Thakur and Misra 1984). 4. Petrography euhedral and contain olivine inclusions and also occurs as euhedral to anhedral crystals 4.1 Harzburgite (Bgure 3e–g). In some of the sections, spinel occurs as dark red vermicular crystals and occasionally Modal composition of harzburgites ranges between magnetite rim surrounded spinel are also observed 69 and 78% olivine, orthopyroxene varying between (Bgure 3h). 15 and 21%, clinopyroxene from 1 to 3%, and spinel ranging between 1 and 2% and mainly shows pro- togranular and porphyroclastic texture. In pro- 5. Analytical techniques togranular texture, olivine and orthopyroxene grains display deformation features like kink bands and Selected samples of harzburgite and dunite were distorted lamellae in orthopyroxene (Bgure 3aand analyzed by a CAMECA SX100 electron micro- b). Recrystallization of olivine around orthopyrox- probe at the Department of Geology and Geo- ene is observed in harzburgites (Bgure 3b). physics, Indian Institute of Technology, Kharagpur Orthopyroxene occurs as large prophyroclasts with (India). Major element compositions of the mineral exsolutions of clinopyroxene (Bgure 3b). In some phases were measured with an accelerating voltage samples, orthopyroxene clasts host olivine inclusions of 15 kV with a beam diameter of 2 lm and probe (Bgure 3c). In porphyroclastic type of texture, large current of 20 nA. Natural and synthetic standards orthopyroxene grains form resorbed shapes and were used during the analysis. Standards are small clinopyroxene crystals with lobate boundaries. jadeite (Na-Ka), Cuor-apatite (F-Ka, P-Ka), NaCl The occurrence of spinels in harzburgite is in the (Cl-Ka), Fe O (Fe-Ka), diopside (Ca-Ka), MgO B 2 3 form of subhedral ( gure 3d).
Load more

Recommended publications
  • Logo Cro Dkom
    SIGMA Support for Improvement in Governance and Management A joint initiative of the OECD and the European Union, principally financed by the EU PARTICIPANTS LIST Regional Conference on Public Procurement Reform in West Balkan Pristina, 16-17 September 2008 Albania Mrs Etleva Kondi Tel: +4 22 77 510 Director Mob. + 68 20 91 234 Public Procurement Agency Fax: +4 22 56 631 Concessions Email: [email protected] Council Ministers, Blvd Deshmoret e Kombit Tirana Mrs Anilda Sefgjini Tel: +4 22 77 513 Deputy Director Mob. + 68 24 12 230 Public Procurement Agency Fax: +4 22 56 631 Council Ministers, Email: [email protected] Blvd Deshmoret e Kombit Tirana Mr. Alfred Bej Tel: +4 22 77 522 Head of Sector Mob. + 68 20 82 157 Public Procurement Agency Fax: +4 22 56 631 Council Ministers, Email: [email protected] Blvd Deshmoret e Kombit Tirana Ms Rezarta Sheshaj Tel: +4 22 77 506 Training Specialist Mob. +69 29 20 065 Public Procurement Agency Fax: +4 22 56 631 Integration and Training Email: [email protected] Council Ministers, Blvd Deshmoret e Kombit Tirana Bosnia and Herzegovina Ms Djinita Foco Tel: +387 33 251 590 Director Mob. + Public Procurement Network Fax: +387 33 251 595 Radiceva 8/V E-mail: [email protected] 71000 Sarajevo Belma Deović Tel: +387 33 251-590 Head of Legal Department Mob. + 387 61 838 309 Public Procurement Agency BiH Fax: + 387 33 251-595 Radiceva 8/V Email: [email protected] 71000 Sarajevo Dragana Ribić Tel: + 387 51 247 340 Head of legal department Mob.
    [Show full text]
  • Front Matter
    Cambridge University Press 0521542553 - Seeing the State: Governance and Governmentality in India Stuart Corbridge, Glyn Williams, Manoj Srivastava and Rene Veron Frontmatter More information Seeing the State Poor people confront the state on an everyday basis all over the world. But how do they see the state, and how are these engage- ments conducted? This book considers the Indian case where people’s accounts, in particular in the countryside, are shaped by a series of encounters that are staged at the local level, and which are also informed by ideas that are circulated by the government and the broader develop- ment community. Drawing extensively on fieldwork conducted in east- ern India and their broad range of expertise, the authors review a series of key debates in development studies on participation, good governance, and the structuring of political society. They do so with particular re- ference to the Employment Assurance Scheme and primary education provision. Seeing the State engages with the work of James Scott, James Ferguson and Partha Chatterjee, and offers a new interpretation of the formation of citizenship in South Asia. Stuart Corbridge is Professor of Geography at the London School of Economics. He is the author or co-author of five books, including Reinventing India (with John Harriss, 2000). Glyn Williams is Senior Lecturer in Geography at King’s College, London. He is the co-editor of a collection of essays on South Asia in a Globalising World (2002). Manoj Srivastava is a Research Associate in the Crisis State Pro- gramme, Development Studies Institute, London School of Economics.
    [Show full text]
  • World Bank Document
    Document of The World Bank FOR OFFICIAL USE ONLY Public Disclosure Authorized Report No. 41 209 -XK INTERNATIONAL DEVELOPMENT ASSOCIATION INTERIM STRATEGY NOTE Public Disclosure Authorized FOR KOSOVO FOR THE PERIOD FYOS November 9,2007 Public Disclosure Authorized South East Europe Country Unit Europe and Central Asia Region Public Disclosure Authorized This document has a restricted distribution and may be used by recipients only in the performance of their official duties. Its contents may not be disclosed without World Bank Authorization The date of the last Interim Strategy Note: March 30,2006 CURRENCY EQUIVALENTS (Exchange Rate Effective November 9,2007) Currency Unit = Euro €1 = 1.45US$ US$1 =€0.68 GOVERNMENT’S FISCAL YEAR January 1 - December 3 1 ABBREVIATIONS AND ACRONYMS AAA Analytical and Advisory Assistance ADA Austrian Development Agency AMIK Association of Microfinance Institutions in Kosovo BEEPS Business Environment and Enterprise Performance Survey BETA Business Environment Technical Assistance CBAK Central Banking Authority of Kosovo CRLP Clean-up and Land Reclamation Project DCC Donor Coordination Center DFID Department for International Development DP Development Partners EAR European Agency for Reconstruction EC European Commission ECA Europe and Central Asia EFSE European Fund for South-East Europe EPIP Education Participation Improvement Project ESTAP Energy Sector Technical Assistance Project EU European Union FDI Foreign Direct Investment FPSG Fiscal Policy Support Grant FSFA Financial Sector Fiduciary Assessment
    [Show full text]
  • Poverty Update for Serbia.Cdr
    Statistical Office of Kosovo Enti i Statistikëë s t Kosov ë s Zavod za statistiku Kosova Consumption Poverty in the Republic of Kosovo in 2009 May 2011 Western Balkans Programmatic Poverty Assessment The World Bank Statistical Office of Kosovo Europe and Central Asia Region Social Satatistics Department Poverty Reduction and Economic Management Unit Living Standards Sector Statistical Office of Kosovo Enti i Statistikëë s t Kosov ë s Zavod za statistiku Kosova Consumption Poverty in the Republic of Kosovo in 2009 Western Balkans Programmatic Poverty Assessment The World Bank Statistical Office of Kosovo Europe and Central Asia Region Social Satatistics Department Poverty Reduction and Economic Management Unit Living Standards Sector May, 2011 This report is a joint publication of the World Bank and the Statistical Office of Kosovo as part of the World Bank's Western Balkans Programmatic Poverty Assessment work program (P112410). The World Bank team was led by Ken Simler (ECSP3), with the assistance of Sachiko Miyata and Yeva Gyulnazaryan (consultants), under the supervision of Benu Bidani (ECSP3). The Statistical Office of Kosovo team was led by Bashkim Bellaqa, assisted by Emina Deliu and Besa Haqifi. Alexandru Cojocaru, Agim Demukaj, Borko Handjiski, Ranjit Nayak, Anita Schwarz, and Manohar Sharma (peer reviewer) provided helpful comments on earlier drafts of this report. Generous financial support from the United Kingdom Department for International Development is gratefully acknowledged. The findings, interpretations, and conclusions expressed in this paper do not necessarily reflect the views of the Executive Directors of The World Bank or the governments they represent. The World Bank does not guarantee the accuracy of the data included in this work.
    [Show full text]
  • Investing in Kosovo 2010 This Conference Is Supported by Foreword
    INVESTING IN KOSOVO 2010 This conference is supported by FOREWORD Foreword HASHIM THAÇI PRIME MINISTER OF THE REPUBLIC OF KOSOVO riends, allow me to share with you my personal Atlantic and regional integrations, through implementing conviction, that in these uncertain times, investing in the highest standards and criteria of good governance, Fa young country such as Kosovo, with a functioning responsibility and transparency. democratic system bolstered by healthy economic indicators presents a positive alternative for your business. Kosovo is a fledgling democracy with a wide spectrum of developmental requirements, which has perhaps been The declaration of independence from the Parliament of reflected in recent events. It will continue to transit through Kosovo on 17 February 2008 was a historical date and the growing pains common to many young nations but created a new stage for the people of Kosovo. will not be detracted from its core aims, central to which is to develop its economy through encouraging private The recognition of the independence of Kosovo from sector growth. 70 nations, among them the most powerful economies in the world, reflects the support the new country has Our government has identified its top priorities to within the international community and the legitimate accelerate the economic and social development right of the people of Kosovo for self-governance. of Kosovo on the way to economic growth and prosperity and I warmly invite you to become a part of We call upon the remaining members of the international this development. community to follow the lead set by the United States and the UK, amongst many others, by embracing our country and recognising our independence.
    [Show full text]
  • World Bank Document
    --- .... - ---------- -- - -- - -- - - -­ THE W 0 R LOB A N K G R 0 U P The Junction WHERE ALL THINGS DIVERSITY & INCLUSION COME TOGETHER FOR CHANGE Public Disclosure Authorized Public Disclosure Authorized Public Disclosure Authorized Public Disclosure Authorized ...to Inclusion and Human Equity Diversity speaker Trevor Wilson animated a thought-provoking session during the Information Solutions Network (ISN) Forum in 2009 that challenged participants to value individual differences in their day-to-day work. Why would the ISN host a session on diversity and inclusion (D&I)? After all, this cluster of about 1,000 staff across the Bank Group is tasked with managing the institution's information and technology-no small feat. "IT at its best is a business enabler, not a compromise an organization's capacity to commodity," said Elisa Liberatori-Prati, achieve its goals. "You can have tolerance the Bank Group's Chief Archivist and, along without respect," said Wilson, who has with Ryan Jones, ISN's D&I Coordinator. been a professional diversity consultant "Along these lines, D&1 has this same for more than 20 years and worked with potential to breathe life into our operations thousands of companies. "We need to in a way that vastly improves what we do." value people because of their differences, and move way beyond mere tolerance." Just like a fickle network connection or ineffective firewall, a poor approach to Likewise, an organization can have nR. T kcaJ~C: I":ln I~:lv~ c:t::lff !:tvmi~d ::Ind div~r dtv withollt indlldnn Indllsinnl_____ is about creating a climate where diversity and make it part of our DNA , diversity is valued.
    [Show full text]
  • World Bank Document
    Document of The World Bank FOR OFFICIAL USE ONLY Public Disclosure Authorized RESTRUCTURING PAPER ON A PROPOSED PROJECT RESTRUCTURING OF AVIAN INFLUENZA CONTROL AND HUMAN PANDEMIC PREPAREDNESS AND RESPONSE PROJECT IDA GRANT NUMBER H272 KOS Public Disclosure Authorized IN THE INITIAL AMOUNT OF SDR 2.0 MILLION (US$3 MILLION EQUIVALENT) AND A RESTRUCTURED AMOUNT OF SDR 2.0 MILLION (US$3 MILLION EQUIVALENT) Public Disclosure Authorized TO THE REPUBLIC OF KOSOVO DECEMBER 18,2009 This document has a restricted distribution and may be used by recipients only in the Public Disclosure Authorized performance of their official duties. Its contents may not otherwise be disclosed without World Bank authorization. ABBREVIATIONS AND ACRONYMS AH Lab Animal Health Laboratory AI Avian Influenza CF Compensation Fund FA0 Food and Agriculture Organization of the United Nations FVA Food and Veterinary Agency GPAI Global Program for Avian Influenza Control and Human Pandemic Preparedness and Response HPAI Highly Pathogenic Avian Influenza ICU Intensive Care Unit IDA International Development Association IPH Institute of Public Health MAFRD Ministry of Agriculture, Forestry and Rural Development MEF Ministry of Economy and Finance MOH Ministry of Health MTR Mid-term Review PDO Project Development Objective PISG Provisional Institutions of Self-Government SOP Standard Operating Procedure UNICEF United Nations Children’s Fund WHO World Health Organization Vice President: Philippe H. LeHouerou Country Director: Jane Armitage Country Manager Ranjit Nayak Sector Manager: Dina Umali-Deininger Task Team Leader: Ibrahim Hackaj KOSOVO Avian Influenza Control and Human Pandemic Preparedness and Response Project TABLE OF CONTENTS Page Data Sheet .......................................................................................................................... 1 ANNEX 1: Proposed Changes ............................................................................................ 3 ANNEX 2: Appraisal Summary Update ............................................................................
    [Show full text]
  • International Migration and the Millennium Development Goals
    International Migration and the Millennium Development Goals andtheMillenniumDevelopment International Migration International Migration and the Millennium Development Goals Selected Papers of the UNFPA Expert Group Meeting Expert Group oftheUNFPA Selected Papers Selected Papers of the UNFPA Expert Group Meeting United Nations Population Fund 220 East 42nd Street New York, New York 10017 www.unfpa.org ISBN 0-89714-755-3 E/1000/2005 INTERNATIONAL MIGRATION AND THE MILLENNIUM DEVELOPMENT GOALS Selected Papers of the UNFPA Expert Group Meeting Marrakech, Morocco 11-12 May 2005 NOTES: The views and opinions expressed in this report are those of the participants who attended the Expert Group Meeting on International Migration and the Millennium Development Goals and do not necessarily reflect those of the United Nations Population Fund (UNFPA). The papers included in this report have been published as submitted. The designations employed and the presentation of material in this publication do not imply the expressions of any opinion whatsoever on the part of UNFPA concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. The term ‘country’ as used in the text of this report refers, as appropriate, to territories or areas. The designations of ‘developed’ and ‘de vel oping’ countries are intended for convenience and do not necessarily express a judgement about the stage reached by a particular country or area in the development process. United Nations
    [Show full text]
  • Q & a with Ranjit Nayak
    Ninth Edition - September 23, 2009 Promoting Inclusion in the Post-Conflict Balkans Public Disclosure Authorized n the former Yugoslavia, a series and Herzegovina, Kosovo, Macedonia, of violent wars erupted during Montenegro, and Serbia, as well as Ithe 1990s. Ethnic conflicts and IFC representatives from Albania and economic disruptions prevailed as a Bosnia-Herzegovina. new map emerged in fits and starts— The group immediately decamped via ultimately yielding seven new states. bus for a unique field trip with some lo- Today, memories of conflict are still cal country office staff. First stop: meet- fresh. In a sub-region where the mere ings with various ethnic and religious presence of a cross or minaret was once communities around Kosovo, including a pretext for violence, it is hardly sur- the Roma, Ashkali, and Egyptians. prising that the Bank Group’s develop- In Fushe-Kosove, near Pristina in ment work is fraught with challenges. central Kosovo, Muhamet Arifi a Roma In the post-conflict Balkan states, from Balkan Sunflowers—an interna- Public Disclosure Authorized perhaps more than any place on tional NGO that promotes reconciliation Earth, the Bank Group’s effectiveness through volunteerism and community is inextricably linked to diversity and engagement—explained why these com- Father Sava Janjic met the Bank’s Chief inclusion. For that reason, Diversity munities face barriers to healthcare and Diversity Officer, Julie Oyegun, and Resident Chief Julie Oyegun recently convened education. A full 40 percent of the Roma Representatives from six Balkan countries. a group of Country Managers in Pris- community lack birth certificates, IDs, or tina, Kosovo, hosted by the Country any form of official documentation.
    [Show full text]
  • Petrogenesis and Geochemical Characteristics of Plagiogranites From
    Chemie der Erde 77 (2017) 183–194 Contents lists available at ScienceDirect Chemie der Erde j ournal homepage: www.elsevier.de/chemer Petrogenesis and geochemical characteristics of plagiogranites from Naga Ophiolite Belt, northeast India: Fractional crystallization of MORB-type magma a,∗ b Ranjit Nayak , B.V. Rao a Department of Earth and Atmospheric Sciences, NIT, Rourkela 769008, India b Department of Geology, Nagaland University, Kohima, Nagaland 797001, India a r t a b i s c l e i n f o t r a c t Article history: The Naga Ophiolite Belt is a part of the Naga-Arakan-Yoma flysch trough that occurs along the Received 11 March 2016 Indo-Myanmar border. It is represented by peridotites, mafic-ultramafic cumulates, mafic volcanics, Received in revised form 31 October 2016 mafic dykes, plagiogranites, pelagic sediments and minor felsic to intermediate intrusives. Minor Accepted 7 November 2016 plagiogranites, gabbros and thin serpentinite bands occur juxtaposed near Luthur, with the slate-phyllite- Editorial handling - Dr. Dewashish metagreywacke sequence (Phokpur Formation) adjacent to the contact. The development of tonalites, Upadhyay trondhjemites and diorites in the oceanic crust, which is grouped as plagiogranites, offers an opportunity to study the process of formation of silicic melts from mafic crust. Plagiogranites from Naga Ophiolite Belt Keywords: Petrology contains moderate SiO2 (51.81–56.71 wt.%), low K2O (0.08–1.65 wt.%) and high Na2O (4.3–5.03 wt.%). The Geochemistry Naga Ophiolite Belt plagiogranites like ocean-ridge granites contain low K2O, high Na2O and CaO. The Plagiogranite rocks investigated from Naga Ophiolite Belt contain TiO2 concentrations above the lower limit for frac- Naga Ophiolite Belt (NOB) tionated Mid Oceanic Ridge Basalt which is above 1 wt% of TiO2 and the ternary plots of A (Na2O + K2O) T Fractional crystallization F(FeO ) M(MgO) and TiO2-K2O-SiO2/50 indicate that the plagiogranite are tholeiitic in character and gabbro samples are calc-alkaline in nature.
    [Show full text]
  • Proquest Dissertations
    INFORMATION TO USERS This manuscript has been reproduced from the microfilm master. UMI films the text directly from the original or copy sutxnitled. Thus, some thesis and dissertation copies are in typewriter face, while others may t>e from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or Indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, beginning at the upper left-hand comer and continuing from left to right in equal sections with small overlaps. Photographs included in the original manuscript have been reproduced xerographically in this copy. Higher quality 6* x 9” black and white photographic prints are available for any photographs or illustrations appearing in this copy for an additional charge. Contact UMI directly to order. Bell & Howell Information and Learning 300 North Zdeb Road, Ann Arbor, Ml 48106-1346 USA 800-521-0600 UMT “INNOVATIONS IN COMMUNICATIONS TECHNOLOGY AND THE STRUCTURE OF SECURITIES MARKETS; A CASE STUDY OF THE TELEGRAPH AND THE RISE OF THE NYSE TO PREEMINENCE. 1830-1860.’ DISSERTATION Presented in Partial Fulfillment of the Requirement for the Degree of Doctor of Philosophy in the Graduate School of The Ohio State University By Sonali Garg, M.A.
    [Show full text]
  • Evaluation of Norwegian Development Cooperation with the Western Balkans
    Evaluation Department Norad Norwegian Agency for Development Cooperation Postal address P.O. Box 8034 Dep. NO-0030 OSLO Evaluation of Norwegian Development Visiting address Ruseløkkveien 26, Oslo, Norway Cooperation with the Western Balkans Tel: +47 22 24 20 30 Fax: +47 22 24 20 31 No. of Copies: 300 Report 7/2010 – Evaluation [email protected] www.norad.no Volume I EVALUATION REPORTS 2.04 Norwegian Peace-building policies: Lessons Learnt and Challenges 11.97 Evaluation of Norwegian Humanitarian Assistance to the Sudan Ahead 12.97 Cooperation for Health DevelopmentWHO’s Support to Programmes at 3.04 Evaluation of CESAR´s activities in the Middle East Funded by Norway Country Level 4.04 Evaluering av ordningen med støtte gjennom paraplyorganiasajoner. Eksemplifisert ved støtte til Norsk Misjons Bistandsnemda og 1.98 “Twinning for Development”. Institutional Cooperation between Public Atlas-alliansen Institutions in Norway and the South 5.04 Study of the impact of the work of FORUT in Sri Lanka: Building 2.98 Institutional Cooperation between Sokoine and Norwegian Agricultural CivilSociety Universities 6.04 Study of the impact of the work of Save the Children Norway in 3.98 Development through Institutions? Institutional Development Promoted Ethiopia: Building Civil Society by Norwegian Private Companies and Consulting Firms 4.98 Development through Institutions? Institutional Development Promoted 1.05 –Study: Study of the impact of the work of FORUT in Sri Lanka and by Norwegian Non-Governmental Organisations Save the Children Norway in Ethiopia: Building Civil Society 5.98 Development through Institutions? Institutional Developmentin 1.05 –Evaluation: Evaluation of the Norad Fellowship Programme Norwegian Bilateral Assistance.
    [Show full text]