Anomalous subsidence on the rifted volcanic margin of Pakistan:: No influence from Deccan plume

被引：29

作者：

Calves, Gerome ^{[1
]}

Clift, Peter D. ^{[1
,2
]}

Inam, Asif ^{[3
]}

机构：

[1] Univ Aberdeen, Sch Geosci, Kings Coll, Aberdeen AB24 3UE, Scotland

[2] Univ Bremen, D-28359 Bremen, Germany

[3] Natl Inst Oceanog, Karachi 75600, Pakistan

来源：

EARTH AND PLANETARY SCIENCE LETTERS | 2008年 / 272卷 / 1-2期

关键词：

subsidence; break-up; plume; Indian Ocean; lithosphere;

D O I：

10.1016/j.epsl.2008.04.042

中图分类号：

P3 [地球物理学]; P59 [地球化学];

学科分类号：

0708 ; 070902 ;

摘要：

The role of hotter than ambient plume mantle in the formation of a rifted volcanic margin in the northern Arabian Sea is investigated using subsidence analysis of a drill site located on the seismically defined Somnath volcanic ridge. The ridge has experienced >4 km of subsidence since 65 Ma and lies within oceanic lithosphere. We estimate crustal thickness to be 9.5-11.5 km. Curiously <400 m of the thermal subsidence Occurred prior to 37 Ma, when Subsidence rates would normally be at a maximum. We reject the hypothesis that this was caused by increasing plume dynamic support after continental break-Lip because the size of the thermal anomalies required are unrealistic (>600 degrees C, especially considering the rapid northward drift of India relative to the Deccan-Reunion hotspot. We suggest that this reflects very slow lithospheric growth, possibly caused by Vigorous asthenospheric convection lasting > 28 m.y., and induced by the steep continent-ocean boundary. Post-rift slow subsidence is also recognized on volcanic margins in the NE Atlantic and SE Newfoundland and cannot be used as a unique indicator of plume mantle involvement in continental bleak-up.Crown Copyright (D 2008 Published by Elsevier B.V All rights reserved.

引用

页码：231 / 239

页数：9

共 56 条

[11] On causal links between flood basalts and continental breakup [J].

Courtillot, V ;

Jaupart, C ;

Manighetti, I ;

Tapponnier, P ;

Besse, J .

EARTH AND PLANETARY SCIENCE LETTERS, 1999, 166 (3-4) :177-195

[12] DECCAN FLOOD BASALTS AND THE CRETACEOUS TERTIARY BOUNDARY [J].

COURTILLOT, V ;

FERAUD, G ;

MALUSKI, H ;

VANDAMME, D ;

MOREAU, MG ;

BESSE, J .

NATURE, 1988, 333 (6176) :843-846

[13] ANOMALOUS HEAT-FLOW AND GEOID ACROSS THE CAPE-VERDE RISE - EVIDENCE FOR DYNAMIC SUPPORT FROM A THERMAL PLUME IN THE MANTLE [J].

COURTNEY, RC ;

WHITE, RS .

GEOPHYSICAL JOURNAL OF THE ROYAL ASTRONOMICAL SOCIETY, 1986, 87 (03) :815-867

[14] ISLAND SUBSIDENCE, HOT SPOTS, AND LITHOSPHERIC THINNING [J].

DETRICK, RS ;

CROUGH, ST .

JOURNAL OF GEOPHYSICAL RESEARCH, 1978, 83 (NB3) :1236-1244

[15]

Duncan R. A., 1990, Proceedings of the Ocean Drilling Program Scientific Results, V115, P3, DOI [DOI 10.2973/ODP.PROC.SR.115.206.1990, DOI 10.2973/0DP.PR0C.SR.115.206.1990]

[16] Extension across the Indian-Arabian plate boundary: The Murray Ridge [J].

Edwards, RA ;

Minshull, TA ;

White, RS .

GEOPHYSICAL JOURNAL INTERNATIONAL, 2000, 142 (02) :461-477

[17]

FISHER RL, 1974, INITIAL REPORTS DEEP, V24, P391

[18] Is "hotspot" volcanism a consequence of plate tectonics? [J].

Foulger, GR ;

Natland, JH .

SCIENCE, 2003, 300 (5621) :921-922

[19] Origin of the northern Indus Fan and Murray Ridge, Northern Arabian Sea:: interpretation from seismic and magnetic imaging [J].

Gaedicke, C ;

Schlüter, HU ;

Roeser, HA ;

Prexl, A ;

Schreckenberger, B ;

Meyer, H ;

Reichert, C ;

Clift, P ;

Amjad, S .

TECTONOPHYSICS, 2002, 355 (1-4) :127-143

[20] STIRRING AND STRUCTURE IN MANTLE STARTING PLUMES [J].

GRIFFITHS, RW ;

CAMPBELL, IH .

EARTH AND PLANETARY SCIENCE LETTERS, 1990, 99 (1-2) :66-78

← 1 2 3 4 5 6 →