Serpentinite enigma of the Rakhabdev lineament in western India: Origin, deformation characterization and tectonic implications
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- SARKAR Dyuti Prakash
- Department of Earth and Planetary Systems Science, Hiroshima University
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- ANDO Jun–ichi
- Department of Earth and Planetary Systems Science, Hiroshima University
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- DAS Kaushik
- Department of Earth and Planetary Systems Science, Hiroshima University
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- CHATTOPADHYAY Anupam
- Department of Geology, University of Delhi
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- GHOSH Gautam
- Centre for Advanced Study, Department of Geology, Presidency University
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- SHIMIZU Kenji
- Kochi Institute for Core Sample Research, JAMSTEC
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- OHFUJI Hiroaki
- Geodynamics Research Center, Ehime University
Abstract
<p>Serpentine mineralogy controls fault rheology in the ocean and continental rift settings to subduction settings and hence can be used to discern the paleo deformational conditions. The Rakhabdev lineament from Rajasthan, India, provides a unique opportunity to understand its tectonic evolution inferred from the deformation microstructures. However, the complexity of surrounding calc–silicate rocks had resulted in a long–driven debate on the origins of these serpentinite rocks. The source rocks of the serpentinites also cannot be determined previously due to complete serpentinization and metasomatism rendering complete alteration of the source rocks. In this study, the serpentinite mineral was analyzed using Raman spectroscopy to accurately characterize its molecular structure. The presence of the antigorite–variety of serpentine mineral indicate towards the origin of Rakhabdev serpentinites in the upper mantle condition. The antigorite serpentinite of Rakhabdev is a hydration product of mantle materials showing high Mg# values obtained from EPMA data. The microstructural and EBSD analysis also indicates two stages of deformation, with deformation of antigorite at upper mantle conditions, followed by their shallow crustal carbonate metasomatism and subsequent deformation of the carbonates, with later stage calcite vein intrusion. This resulted in the appearance of antigorite in contact with calcite, dolomite, talc, tremolite, and chlorite. The exhumation of mantle wedge antigorite serpentinite is, therefore, indicating a paleo–subduction zone culminating in a crustal–scale collision boundary expressed as arcuate discontinuous bodies forming the Rakhabdev lineament.</p>
Journal
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- Journal of Mineralogical and Petrological Sciences
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Journal of Mineralogical and Petrological Sciences 115 (2), 216-226, 2020
Japan Association of Mineralogical Sciences
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Details 詳細情報について
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- CRID
- 1390285300155901312
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- NII Article ID
- 130007839869
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- ISSN
- 13493825
- 13456296
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- Text Lang
- en
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- Data Source
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- JaLC
- Crossref
- CiNii Articles
- KAKEN
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- Abstract License Flag
- Disallowed