THE IMPORTANCE OF SMALL-SCALE FAULTING IN REGIONAL EXTENSION
THE IMPORTANCE OF SMALL-SCALE FAULTING IN REGIONAL EXTENSION
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DOI：
10.1038/351391a0
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发表时间：
1991-05-30
期刊：
影响因子：
64.8
通讯作者：
YIELDING, G
中科院分区：
文献类型：
--
作者：
WALSH, J;WATTERSON, J;YIELDING, G
在许多张性盆地的研究中反复出现的一个观察结果是，在正断层上（例如，在地震反射剖面上）可见的张性量明显小于地壳厚度和热沉降所指示的张性量1-5。解释这种差异的一种机制是小规模的断层，偏移量太小，无法通过地震来解决6，7。 但是，地震研究8-10表明，小断层只负责一个活跃地区的总地震矩的一小部分。Scholz和Cowie 11最近试图通过结合描述断层长度和位移分布的标度律，将这种方法扩展到有限变形区间结束时的总应变。 在这里，我们提出的断层位移数据，直接与Scholz和Cowie的结论相冲突，并暗示，高达40%的扩展可能会错过总结断层偏移盆地配置文件。 在一个长的形变间隔结束时的断层群可能与在任何一个时刻引起地震群的断层群有很大的不同。
A RECURRING observation in many studies of extensional basins has been that the amount of extension visible on normal faults (for example, on seismic reflection profiles) is significantly less than the amount of extension indicated by crustal thickness and thermal subsidence 1-5. One mechanism suggested to account for this discrepancy is small-scale faulting, with offsets too small to be resolved seismically 6,7. But earthquake studies 8-10 indicate that small faults are responsible for only a small fraction of the total seismic moment in an active area. Scholz and Cowie 11 have recently attempted to extend this approach to the total strain at the end of a finite deformation interval by combining scaling laws describing the distributions of fault lengths and displacements. Here we present fault displacement data that directly conflict with Scholz and Cowie's conclusions, and imply that up to 40% of the extension may be missed by summing fault offsets on basin profiles. The fault population at the end of a long deformation interval may differ substantially from that responsible for the earthquake population at any one time.