Formation of cratonic mantle keels by arc accretion: Evidence from S receiver functions
Formation of cratonic mantle keels by arc accretion: Evidence from S receiver functions
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DOI：
10.1029/2010gl044366
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发表时间：
2010-09
影响因子：
5.2
通讯作者：
M. Miller;D. Eaton
中科院分区：
文献类型：
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作者：
M. Miller;D. Eaton
圈定地幔界面可以为理解大陆的形成提供重要线索。利用S波接收函数研究了温哥华岛至巴芬岛断面上的岩石圈结构。观测到的Sp转换波允许在构造板块预期的深度范围内解释边界。接收函数在不列颠哥伦比亚省以下浅层(∼85公里)表现出明显的负振幅特征，解释为岩石圈-软流圈边界，在科迪勒拉东部边缘突然加深到加拿大盾下260公里处的∼。岩石圈中部不连续面延伸到几个约1.8Ga的巨型陆缘岩浆弧下，与弧吸积形成克拉通岩石圈一致。这个模型为克拉通内部的全球中岩石圈不连续提供了一个可信的解释，并有助于理解它们的形成。
Delineating mantle interfaces can provide important clues for understanding the formation of continents. We use S‐wave receiver functions to investigate lithospheric structure along a transect extending from Vancouver Island to Baffin Island. Observed Sp converted waves allow for interpretation of boundaries in the depth range expected for tectonic plates. Receiver functions show a distinct negative amplitude feature, interpreted as the lithosphere‐asthenosphere boundary, at shallow depths beneath British Columbia (∼85km), deepening abruptly at the eastern edge of the Cordillera to ∼260km beneath the Canadian Shield. Dipping mid‐lithospheric discontinuities extend beneath several giant ca. 1.8 Ga epicontinental magmatic arcs, consistent with formation of cratonic lithosphere by arc accretion. This model provides a plausible explanation for global mid‐lithospheric discontinuities within cratons and aids in understanding their formation.