Oceanic plateaus as meteorite impact signatures
Oceanic plateaus as meteorite impact signatures
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DOI：
10.1038/299341a0
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发表时间：
1982-09
期刊：
影响因子：
64.8
通讯作者：
G. Rogers
中科院分区：
文献类型：
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作者：
G. Rogers
海洋高原是一组神秘的深海构造。这些会是古代陨石撞击的痕迹吗？虽然在大陆上已经确定了从前寒武纪到近代的许多确定的和怀疑的撞击地点，但迄今为止还没有在海洋中确定。与大多数大陆板块相比，海底相对年轻，在扩张中心不断更新，在俯冲带不断破坏。尽管如此，大约一半的海洋盆地是白垩纪或更早的（太平洋海底如图1所示），它们代表着地质上非常稳定的平台。注意到，例如，记录的主要大陆撞击的数量少于100兆尔（15个直径为10公里的陨石坑，包括苏联的2个直径为50公里的陨石坑），也应该存在相当数量的这个年龄的海洋撞击结构。当与海洋盆地的大小和平均年龄相关联时，从陆地上的撞击结构推导出的递推关系表明，海洋中的撞击结构应该更多（图2）。关键问题是要寻找什么。我在这里讨论了考虑稀疏分布的深海高原可能是候选者的原因。
The oceanic plateaus are an enigmatic set of deep ocean structures1-5. Could these be signatures of ancient meteorite impacts? While numerous confirmed and suspected impact sites, ranging in age from Precambrian to Recent, have been identified on the continents6, none has thus far been identified in the oceans. The ocean floor is relatively young compared with most of the continental land masses and is constantly being renewed at spreading centres and destroyed in subduction zones. Nevertheless, roughly half of the ocean basins are of Cretaceous age or older (the Pacific ocean floor is shown in Fig. 1) and they represent geologically very stable platforms. Noting, for example, the number of major continental impacts documented to be less than 100 Myr old (15 craters with diameters > 10 km including two > 50 km in the Soviet Union6), a significant number of oceanic impact structures of this age should also be present. A recurrence relation derived from impact structures on land, when correlated for the size and average age of the ocean basins, indicates that impact structures should be more numerous in the oceans (Fig. 2). The key problem is what to look for. I discuss here reasons for considering the sparsely scattered deep ocean plateaus to be likely candidates.