Impact origin for the greater Ontong Java Plateau?
Impact origin for the greater Ontong Java Plateau?
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DOI：
10.1016/s0012-821x(03)00629-0
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发表时间：
2004-01-30
影响因子：
5.3
通讯作者：
Coffin, MF
中科院分区：
文献类型：
--
作者：
Ingle, S;Coffin, MF
类似于120 Ma Ontong爪哇高原和邻近的，同时代的瑙鲁，东马里亚纳和（可能）Pigafetta盆地洪水玄武岩在西赤道太平洋组成地球上最大的洪水玄武岩省。来自该省的地球物理、地球化学和地球动力学证据很难与地幔柱模型相一致;没有明显的热点源或热点轨迹，与侵位相关的地壳轻微隆起，与正常洋壳或其他洋台和海底脊相比的轻微总沉降，上地幔浅层高度熔融，玄武岩含水量低，玄武岩中铂族元素的富集，以及类似于300公里深、地震缓慢的地幔根，更符合撞击火流星的后果。一个直径约为20公里的物体撞击相对年轻（约2000万年）的太平洋岩石圈并穿透到最上部的软流圈，可能会引发上地幔的大规模减压熔融，并可能导致更大的Ontong Java高原的就位。(C)2003 Elsevier B. V.保留所有权利。
The similar to 120 Ma Ontong Java Plateau and neighboring, contemporaneous Nauru, East Mariana, and (probably) Pigafetta basin flood basalts in the western equatorial Pacific Ocean comprise the Earth's largest flood basalt province. Geophysical, geochemical, and geodynamic evidence from the province are difficult to reconcile with mantle plume models; absence of an obvious hotspot source or track, minor crustal uplift associated with emplacement, minor total subsidence compared with normal oceanic crust or other oceanic plateaus and submarine ridges, high degrees of melting at shallow, upper mantle depths, low water contents of basalts, enrichment of platinum group elements in basalts, and a similar to 300 km deep, seismically slow mantle root are more consistent with the consequences of an impacting bolide. An object similar to 20 km in diameter impacting relatively young (similar to 20 Myr) Pacific lithosphere and penetrating into the uppermost asthenosphere would have initiated massive decompression melting in the upper mantle, and may have resulted in emplacement of the greater Ontong Java Plateau. (C) 2003 Elsevier B.V. All rights reserved.