Global correlation of lower mantle structure and past subduction
Global correlation of lower mantle structure and past subduction
复制标题
DOI：
10.1002/2016gl068827
复制
发表时间：
2016-05-28
影响因子：
5.2
通讯作者：
Bull, Abigail L.
中科院分区：
文献类型：
--
作者：
Domeier, Mathew;Doubrovine, Pavel V.;Bull, Abigail L.
全球地震层析成像的进步日益推动了对地球深部地幔俯冲岩石圈的识别，创造了将板块构造和地幔演化联系起来的新机会。其中最主要的是寻求一个强大的俯冲参照框架，其中俯冲岩石圈的地幔组合被用来在固定在地球深处的绝对框架内重建过去的地表构造。然而，到目前为止，下地幔结构和过去的俯冲之间的联系是定性的和相互冲突的，因此这种联系的假设还没有得到定量证实。结果表明，重建的130MyR俯冲带与深度600-2300公里的S波速正异常之间存在显著的时间-深度递进关联，但更大的时间和深度之间的进一步关联目前还不明显。这种相关性表明，下地幔板块下沉速率平均在1.1~1.9 cmyr(-1)之间。
Advances in global seismic tomography have increasingly motivated identification of subducted lithosphere in Earth's deep mantle, creating novel opportunities to link plate tectonics and mantle evolution. Chief among those is the quest for a robust subduction reference frame, wherein the mantle assemblage of subducted lithosphere is used to reconstruct past surface tectonics in an absolute framework anchored in the deep Earth. However, the associations heretofore drawn between lower mantle structure and past subduction have been qualitative and conflicting, so the very assumption of a correlation has yet to be quantitatively corroborated. Here we show that a significant, time-depth progressive correlation can be drawn between reconstructed subduction zones of the last 130 Myr and positive S wave velocity anomalies at 600-2300 km depth, but that further correlation between greater times and depths is not presently demonstrable. This correlation suggests that lower mantle slab sinking rates average between 1.1 and 1.9 cmyr(-1).