Were the deccan flood basalts derived in part from ancient oceanic crust within the indian continental lithosphere?
Deep mantle plumes supposedly incorporate deeply subducted eclogitized oceanic crust, and continental flood basalts (CFBs) are now thought by some to be derived from such eclogite-bearing peridotite plumes. Eclogite-peridotite mixtures have much lower solidi (and produce much greater melt fractions...
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ftiitbombay:oai:dsapce.library.iitb.ac.in:100/3029 2023-05-15T16:47:45+02:00 Were the deccan flood basalts derived in part from ancient oceanic crust within the indian continental lithosphere? SHETH, HC 2005 http://dspace.library.iitb.ac.in/xmlui/handle/10054/13790 https://doi.org/10.1016/S1342-937X(05)71112-6 http://hdl.handle.net/100/3029 en eng ELSEVIER SCIENCE BV GONDWANA RESEARCH,8(2)109-127 1342-937X http://dx.doi.org/10.1016/S1342-937X(05)71112-6 http://dspace.library.iitb.ac.in/xmlui/handle/10054/13790 http://hdl.handle.net/100/3029 Deccan Volcanism Flood Basalt Iceland Eclogite Mantle Plume Major-Element Heterogeneity Mantle Plumes Hot-Spot Chemical Classification Picrite Basalts Beneath Iceland Volcanic-Rocks Western India Evolution Magmas Review 2005 ftiitbombay https://doi.org/10.1016/S1342-937X(05)71112-6 2021-06-03T17:51:03Z Deep mantle plumes supposedly incorporate deeply subducted eclogitized oceanic crust, and continental flood basalts (CFBs) are now thought by some to be derived from such eclogite-bearing peridotite plumes. Eclogite-peridotite mixtures have much lower solidi (and produce much greater melt fractions for a given temperature) than peridotite. Ferich (eclogite- or pyroxenite-bearing) sources have been inferred for many CFBs. However, plumes with considerable amounts of eclogite should have difficulty in upwelling owing to the high density of eclogite. Besides, CFBs are always located along pre-existing lithospheric structures (suture zones, edges of thick cratons) and commonly associated with lithospheric rifting and continental breakup. India ' s major late Mesozoic CFB, the Deccan Traps, erupted through rift zones and a new continental margin that had developed along ancient suture zones traversing the subcontinent. Many Deccan basalts are too Fe-rich to have been in equilibrium with a peridotite mantle source, and have commonly been considered to be significantly fractionated derivatives of picritic liquids. However, it is possible to view them as relatively less evolved liquids derived from a source with extra fertility (i.e., an Fe-rich source). A new non-plume, plate tectonic model for Icelandic hotspot volcanism involves melting of a shallowly recycled slab of eclogitized Iapetus oceanic crust formerly trapped along the Caledonian suture. The model explains the geochemical-petrological characteristics of Icelandic basalts, and is consistent With passive upper mantle upwelling under Iceland inferred from recent seismic tomography. Based on the petrological and geochemical features of the Deccan flood basalts of the type section, in the Western Ghats, I propose that old, eclogitized oceanic crust trapped in the ancient Indian suture zones could have produced voluminous. basaltic melts during the Deccan event. Review Iceland DSpace@IIT Bombay (Indian Institute of Technology) Indian Gondwana Research 8 2 109 127 |
institution |
Open Polar |
collection |
DSpace@IIT Bombay (Indian Institute of Technology) |
op_collection_id |
ftiitbombay |
language |
English |
topic |
Deccan Volcanism Flood Basalt Iceland Eclogite Mantle Plume Major-Element Heterogeneity Mantle Plumes Hot-Spot Chemical Classification Picrite Basalts Beneath Iceland Volcanic-Rocks Western India Evolution Magmas |
spellingShingle |
Deccan Volcanism Flood Basalt Iceland Eclogite Mantle Plume Major-Element Heterogeneity Mantle Plumes Hot-Spot Chemical Classification Picrite Basalts Beneath Iceland Volcanic-Rocks Western India Evolution Magmas SHETH, HC Were the deccan flood basalts derived in part from ancient oceanic crust within the indian continental lithosphere? |
topic_facet |
Deccan Volcanism Flood Basalt Iceland Eclogite Mantle Plume Major-Element Heterogeneity Mantle Plumes Hot-Spot Chemical Classification Picrite Basalts Beneath Iceland Volcanic-Rocks Western India Evolution Magmas |
description |
Deep mantle plumes supposedly incorporate deeply subducted eclogitized oceanic crust, and continental flood basalts (CFBs) are now thought by some to be derived from such eclogite-bearing peridotite plumes. Eclogite-peridotite mixtures have much lower solidi (and produce much greater melt fractions for a given temperature) than peridotite. Ferich (eclogite- or pyroxenite-bearing) sources have been inferred for many CFBs. However, plumes with considerable amounts of eclogite should have difficulty in upwelling owing to the high density of eclogite. Besides, CFBs are always located along pre-existing lithospheric structures (suture zones, edges of thick cratons) and commonly associated with lithospheric rifting and continental breakup. India ' s major late Mesozoic CFB, the Deccan Traps, erupted through rift zones and a new continental margin that had developed along ancient suture zones traversing the subcontinent. Many Deccan basalts are too Fe-rich to have been in equilibrium with a peridotite mantle source, and have commonly been considered to be significantly fractionated derivatives of picritic liquids. However, it is possible to view them as relatively less evolved liquids derived from a source with extra fertility (i.e., an Fe-rich source). A new non-plume, plate tectonic model for Icelandic hotspot volcanism involves melting of a shallowly recycled slab of eclogitized Iapetus oceanic crust formerly trapped along the Caledonian suture. The model explains the geochemical-petrological characteristics of Icelandic basalts, and is consistent With passive upper mantle upwelling under Iceland inferred from recent seismic tomography. Based on the petrological and geochemical features of the Deccan flood basalts of the type section, in the Western Ghats, I propose that old, eclogitized oceanic crust trapped in the ancient Indian suture zones could have produced voluminous. basaltic melts during the Deccan event. |
format |
Review |
author |
SHETH, HC |
author_facet |
SHETH, HC |
author_sort |
SHETH, HC |
title |
Were the deccan flood basalts derived in part from ancient oceanic crust within the indian continental lithosphere? |
title_short |
Were the deccan flood basalts derived in part from ancient oceanic crust within the indian continental lithosphere? |
title_full |
Were the deccan flood basalts derived in part from ancient oceanic crust within the indian continental lithosphere? |
title_fullStr |
Were the deccan flood basalts derived in part from ancient oceanic crust within the indian continental lithosphere? |
title_full_unstemmed |
Were the deccan flood basalts derived in part from ancient oceanic crust within the indian continental lithosphere? |
title_sort |
were the deccan flood basalts derived in part from ancient oceanic crust within the indian continental lithosphere? |
publisher |
ELSEVIER SCIENCE BV |
publishDate |
2005 |
url |
http://dspace.library.iitb.ac.in/xmlui/handle/10054/13790 https://doi.org/10.1016/S1342-937X(05)71112-6 http://hdl.handle.net/100/3029 |
geographic |
Indian |
geographic_facet |
Indian |
genre |
Iceland |
genre_facet |
Iceland |
op_relation |
GONDWANA RESEARCH,8(2)109-127 1342-937X http://dx.doi.org/10.1016/S1342-937X(05)71112-6 http://dspace.library.iitb.ac.in/xmlui/handle/10054/13790 http://hdl.handle.net/100/3029 |
op_doi |
https://doi.org/10.1016/S1342-937X(05)71112-6 |
container_title |
Gondwana Research |
container_volume |
8 |
container_issue |
2 |
container_start_page |
109 |
op_container_end_page |
127 |
_version_ |
1766037861300174848 |