Effective elastic thickness of Ninetyeast Ridge and its implication for tectonic evolution

doi:10.3969/j.issn.1001-909X.2016.01.002

Abstract

Abstract: The effective elastic thickness(T_e) which depends on the deep lithospheric temperature structure and crustal compositions, represents the lithospheric ability to resist deformation. The Ninetyeast Ridge(NER), one of the longest seamount in the world, has been studied by many researchers over its original and process. However, the complicated tectonic activities cause that it is too difficult to uncover the evolution of the NER. Here we investigated the NER in terms of T_e with convolution method and obtained its spatial variations of T_e. The results show that values vary from 0 to 35 km. T_e is characterized as high value (averaging 20 km) in the north section (8°N~1°N), low value (averaging less than 5 km) in the middle part (1°N~15°S) and high value (averaging 30 km) in the south section (15°S~30°S), which are associated with three stages of volcanic activities of Kerguelen hotspot. In addition, the variations of values reflect the adjustment of relative position between Southeast Indian Ridge and hot spot during the evolution of NER and further prove that the NER is influenced and controlled by the Kerguelen hotspot, Indian plate's drift and Southeast Indian Ridge's jump. Finally, by combining with the evidence of ROYER's plate reconstruction, a model was proposed to show the evolution of Ninetyeast Ridge.

Key words: convolution method, effective elastic thickness, Ninetyeast Ridge, tectonic evolution

CLC Number:

P313

JI Fei, GAO Jin-yao, ZHANG Tao, YANG Chun-guo, DING Wei-feng. Effective elastic thickness of Ninetyeast Ridge and its implication for tectonic evolution[J]. Journal of Marine Sciences, 2016, 34(1): 8-17.

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