Geology and geochemistry of Pachmarhi dykes and sills, Satpura Gondwana Basin, central India: problems of dyke-sill-flow correlations in the Deccan Traps
DSpace at IIT Bombay
View Archive InfoField | Value | |
Title |
Geology and geochemistry of Pachmarhi dykes and sills, Satpura Gondwana Basin, central India: problems of dyke-sill-flow correlations in the Deccan Traps
|
|
Creator |
SHETH, HC
RAY, JS RAY, R VANDERKLUYSEN, L MAHONEY, JJ KUMAR, A SHUKLA, AD DAS, P ADHIKARI, S JANA, B |
|
Subject |
tectonic zone
madhya-pradesh trace-element fractional crystallization continental-margin volcanic province basalt volcanism delakhari sill western ghats pb-isotope volcanism continental flood basalt dyke swarm deccan traps gondwana |
|
Description |
Many tholeiitic dyke-sill intrusions of the Late Cretaceous Deccan Traps continental flood basalt province are exposed in the Satpura Gondwana Basin around Pachmarhi, central India. We present field, petrographic, major and trace element, and Sr-Nd-Pb isotope data on these intrusions and identify individual dykes and sills that chemically closely match several stratigraphically defined formations in the southwestern Deccan (Western Ghats). Some of these formations have also been identified more recently in the northern and northeastern Deccan. However, the Pachmarhi intrusions are significantly more evolved (lower Mg numbers and higher TiO(2) contents) than many Deccan basalts, with isotopic signatures generally different from those of the chemically similar lava formations, indicating that most are not feeders to previously characterized flows. They appear to be products of mixing between Deccan basalt magmas and partial melts of Precambrian Indian amphibolites, as proposed previously for several Deccan basalt lavas of the lower Western Ghats stratigraphy. Broad chemical and isotopic similarities of several Pachmarhi intrusions to the northern and northeastern Deccan lavas indicate petrogenetic relationships. Distances these lava flows would have had to cover, if they originated in the Pachmarhi area, range from 150 to 350 km. The Pachmarhi data enlarge the hitherto known chemical and isotopic range of the Deccan flood basalt magmas. This study highlights the problems and ambiguities in dyke-sill-flow correlations even with extensive geochemical fingerprinting.
|
|
Publisher |
SPRINGER
|
|
Date |
2011-08-29T13:46:31Z
2011-12-26T12:58:37Z 2011-12-27T05:48:51Z 2011-08-29T13:46:31Z 2011-12-26T12:58:37Z 2011-12-27T05:48:51Z 2009 |
|
Type |
Article
|
|
Identifier |
CONTRIBUTIONS TO MINERALOGY AND PETROLOGY, 158(3), 357-380
0010-7999 http://dx.doi.org/10.1007/s00410-009-0387-4 http://dspace.library.iitb.ac.in/xmlui/handle/10054/12099 http://hdl.handle.net/10054/12099 |
|
Language |
en
|
|