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用三维有限元模拟方法研究了海洋转换断层下部的温度结构。我们说明,使用岩石层脆性弱化的流变可以沿着转换断层形成地幔强烈上涌和温度升高的区域;推测邻近转换断层中心部位的岩石层温度最高、厚度最薄。以前采用简化的流变定律模拟岩石层及其下部软流层的行为,推测海洋转换断层底部地幔温度比相邻板内的地幔温度低很多,在其中心处岩石层最厚。由于考虑了更真实的脆性流变,所以本研究计算得到了相对高温的热结构。此温度结构与洋脊-转换断层环境中的大量观测结果相符。这些观测资料包括地震活动的深度、沿洋脊临近部位的地球化学异常以及在板块运动变化过程中长的转换断层有分裂为小的内部扩张中心的趋势。
The temperature structure of the lower part of the oceanic conversion fault was studied by using the three-dimensional finite element method. We show that the use of lithospheric brittle weakened rheology can lead to strong upwelling and temperature increase of the mantle along the transition fault; it is assumed that the lithosphere at the center of the adjacent transition fault has the highest temperature and the thinnest thickness. In the past, the simplified rheology was used to simulate the behavior of the lithosphere and its lower asthenosphere. It is speculated that the temperature of the bottom mantle beneath the transition oceanic crust was much lower than that of the adjacent mantle, with the thickest lithosphere at its center. Due to the more realistic brittle rheology, the thermal structure of relatively high temperature was calculated in this study. This temperature structure is consistent with a large number of observations in ocean ridge-transitional fault environments. These observations include the depth of seismic activity, geochemical anomalies along the vicinity of the ocean ridge, and the tendency of long transitional faults to split into smaller centers of internal expansion during plate-movement changes.