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Correlations between silicic volcanic rocks of the St Mary's Islands (southwestern India) and eastern Madagascar: implications for Late Cretaceous India-Madagascar reconstructions

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Title Correlations between silicic volcanic rocks of the St Mary's Islands (southwestern India) and eastern Madagascar: implications for Late Cretaceous India-Madagascar reconstructions
 
Creator MELLUSO, L
SHETH, HC
MAHONEY, JJ
MORRA, V
PETRONE, CM
STOREY, M
 
Subject trans-atlantic correlation
etendeka igneous province
arabian flood volcanism
northern madagascar
basalt province
magma types
hot-spot
break-up
gondwana
geochemistry
 
Description The St Mary's, Islands (southwestern India) expose silicic volcanic and sub-volcanic rocks (rhyolites and granophyric dacites) emplaced contemporaneously with the Cretaceous igneous province of Madagascar, roughly 88-90 Ma ago. I he St Mary's Islands rocks have phenocrysts of plagioclase, clinopyroxene, orthopyroxene and opaque oxide, Moderate enrichment in the incompatible elements, (e.g. Zr 580 720 ppm, Nb 43 53 ppan, La/Yb(a) 0.9 7.2), relatively low initial (87)Sr/(86)Sr (0.7052 0.7055) and near-chondritic initial (143)Nd/(144)Nd (0.51248 0.51249), They have mineral chemical, whole-rock chemical and isotopic Compositions very close to those of rhyolites exposed between Vatomandry Ilaka and Mananjary in eastern Madagascar, and are distinctly different from rhyolites front other sectors of the Madagascan province. We therefore postulate that the St Mary's and the Vatomandry-Ilaka Mananjary silicic rock outcrops were adjacent before the Late Cretaceous rifting that split Madagascar from India, If so, they provide a valuable tool to check and aid traditional Cretaceous India Madagascar reconstructions based on palaeomagnetism, matching Precambrian geological features, and geometric fitting of continental shelves,
 
Publisher GEOLOGICAL SOC PUBL HOUSE
 
Date 2011-07-30T07:16:03Z
2011-12-26T12:52:43Z
2011-12-27T05:39:34Z
2011-07-30T07:16:03Z
2011-12-26T12:52:43Z
2011-12-27T05:39:34Z
2009
 
Type Article
 
Identifier JOURNAL OF THE GEOLOGICAL SOCIETY, 166(), 283-294
0016-7649
http://dspace.library.iitb.ac.in/xmlui/handle/10054/7884
http://hdl.handle.net/10054/7884
 
Language en