Back-Arc Extension of the Central Bransfield Basin Induced by Ridge-Trench Collision: Implications From Ambient Noise Tomography and Stress Field Inversion

被引：9

作者：

Li, Wei ^{[1
,2
]}

Yuan, Xiaohui ^{[1
]}

Heit, Benjamin ^{[1
]}

Schmidt-Aursch, Mechita C. ^{[3
]}

Almendros, Javier ^{[4
]}

Geissler, Wolfram H. ^{[3
]}

Chen, Yun ^{[2
,5
]}

机构：

[1] Deutsch GeoForschungsZentrum GFZ, Potsdam, Germany

[2] Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing, Peoples R China

[3] Helmholtz Zentrum Polar & Meeresforsch, Alfred Wegener Inst, Bremerhaven, Germany

[4] Univ Granada, Andalusian Inst Geophys, Granada, Spain

[5] CAS Ctr Excellence Deep Earth Sci, Guangzhou, Peoples R China

来源：

GEOPHYSICAL RESEARCH LETTERS | 2021年 / 48卷 / 21期

基金：

中国国家自然科学基金;

关键词：

ambient noise tomography; S-wave velocity structure; back-arc extension; ridge-trench collision; Bransfield Basin; Phoenix Plate; SURFACE-WAVE DISPERSION; DECEPTION ISLAND VOLCANO; SOUTH SHETLAND ISLANDS; ANTARCTIC PENINSULA; VELOCITY STRUCTURE; RIFTED MARGINS; SCOTIA RIDGE; STRAIT; EVOLUTION; BENEATH;

D O I：

10.1029/2021GL095032

中图分类号：

P [天文学、地球科学];

学科分类号：

07 ;

摘要：

The Bransfield Basin is a young (similar to 4 Ma) back-arc basin related to the remnant subduction of the Phoenix Plate that once existed along the entire Pacific margin of the Antarctic Peninsula. Based on a recently deployed amphibious seismic network, we use ambient noise tomography to obtain the S-wave velocity structure in the Central Bransfield Basin (CBB). Combining with the stress field inverted from focal mechanisms, our images reveal that the CBB suffers a significant extension in the northwest-southeast direction. The extension is strongest in the northeastern CBB with associated mantle exhumation and weakens to the southwest with decoupled deformations between the upper crust and lithospheric mantle. Such an along-strike variation of extension can be explained by slab window formation and forearc rotation, which are associated with the Phoenix Plate detachment during the ridge-trench collisions at the southwest of the Hero Fracture Zone.

引用

页数：12