Seismic anisotropy and mantle structure of the Rae craton, central Canada, from joint interpretation of SKS splitting and receiver functions
Seismic anisotropy and mantle structure of the Rae craton, central Canada, from joint interpretation of SKS splitting and receiver functions
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DOI：
10.1016/j.precamres.2012.03.003
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发表时间：
2013-07
影响因子：
3.8
通讯作者：
D. Snyder;R. Berman;J. Kendall;M. Sanborn-Barrie
中科院分区：
文献类型：
--
作者：
D. Snyder;R. Berman;J. Kendall;M. Sanborn-Barrie
1992年至2011年期间，努纳武特36个台站记录的地震，并使用接收函数和SKS分裂技术进行了联合分析，表明北方哈德逊湾和巴芬岛地区下方的岩石圈存在多个倾斜各向异性层。突出的不连续性表明，在10个测站下方50至150公里的深度处，地层倾角为6-30°。雷克拉通东南部各向异性组构中的一组区域性连续不连续面呈东南缓倾，与赫恩和Meta Incognita-Sugluk地块下方的逆冲作用一致。SKS分裂记录在12个站点表明模式的特点，两层的各向异性织物。更深的结构以及在其他台站记录的单一快速偏振方向似乎与最近的板块运动一致。哈德逊湾北方的南安普顿岛及其以南各站的浅层组构取向与已知的哈德逊造山带早期（前1.85 Ga）阶段形成的地壳组构取向一致。较浅的织物北部和西部的南安普顿岛有一个更北的方向，并与西倾的不连续性，可能对应于新太古代增生的中太古代北雷域中央雷域。
Earthquakes recorded at 36 stations in Nunavut between 1992 and 2011 and analyzed jointly using receiver-function and SKS-splitting techniques indicate the presence of multiple, dipping anisotropic layers in the lithosphere beneath the northern Hudson Bay and Baffin Island region. Prominent discontinuities indicate layers interpreted to dip at 6–30° at depths between 50 and 150km beneath ten of the stations. One set of regionally continuous discontinuities in anisotropic fabric in the southeastern Rae craton dip gently southeast consistent with underthrusting beneath the Hearne and Meta Incognita-Sugluk blocks. SKS splitting recorded at twelve stations indicate patterns characteristic of two layers of anisotropic fabric. The deeper fabric as well as the single fast polarization direction recorded at other stations appears aligned with recent plate motion. The shallower fabric orientations at stations on and south of Southampton Island in northern Hudson Bay are consistent with known crustal fabric orientations formed during early (pre-1.85Ga) stages of the Hudsonian orogeny. The shallower fabric north and west of Southampton Island has a more northerly orientation and is associated with west-dipping discontinuities that may correspond to Neoarchean accretion of the Mesoarchean north Rae domain to the central Rae domain.