Seismic characteristics of a Precambrian pluton and its adjacent rocks.
Seismic characteristics of a Precambrian pluton and its adjacent rocks.
复制标题
前寒武纪岩体及其邻岩的地震特征。
DOI：
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发表时间：
1983
期刊：
影响因子：
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通讯作者：
L. Jones
中科院分区：
文献类型：
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作者：
Z. Hajnal;M. R. Stauffer;M. S. King;P. F. Wallis;H. Wang;L. Jones
地面、钻孔和实验室声学测量都证实了加拿大Flin Flon地区的变质火山岩、变质沉积岩和深成岩中存在近地表低速带。该区域是由高频率的开放裂缝造成的，从地表延伸到5至44 m的深度，尽管偶尔开放裂缝延伸到至少60 m。随着大裂缝出现频率的增加，声速呈线性下降;然而，具体情况因不同地点而异，这取决于几种地质特征，包括岩石类型和非裂缝孔隙度。实验室声波数据表明，在火山岩和深成岩中微裂纹密度非常低。从花岗岩体中心的声波测井信息得到的合成地震记录与附近的多次地震剖面进行了比较。这表明近地表低速带衰减了大部分高频地震能量。然而，剩下的低频部分...
Surface, borehole, and laboratory acoustic measurements all confirm the existence of a near‐surface low‐velocity zone in metavolcanic, metasedimentary, and plutonic rocks of the Flin Flon region of Canada. This zone is caused by a high frequency of open fractures and extends from the surface to depths of between 5 and 44 m, although occasional open fractures extend to at least 60 m. There is a linear decrease in sonic velocity with increasing frequency of large fractures; the details, however, vary for different sites, depending upon several geologic features including rock type and nonfracture porosity. Laboratory sonic data indicate very low microcrack densities in the volcanic and plutonic rocks. Synthetic seismograms derived from sonic log information from the center of the granitic pluton have been compared with a nearby multifold seismic profile. This shows that the near‐surface low‐velocity zone attenuates most of the high‐frequency seismic energy. However, the remaining low‐frequency portion of th...