Studies on40Ar/39Ar thermochronology of strike-slip time of the Tan-Lu fault zone and their tectonic implications
Studies on40Ar/39Ar thermochronology of strike-slip time of the Tan-Lu fault zone and their tectonic implications
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DOI：
10.1007/bf02875393
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发表时间：
2001-11
期刊：
影响因子：
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通讯作者：
Guang Zhu;Chuanzhong Song;Daoxuan Wang;Guosheng Liu;Jiawei Xu
中科院分区：
文献类型：
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作者：
Guang Zhu;Chuanzhong Song;Daoxuan Wang;Guosheng Liu;Jiawei Xu
在郯庐断裂带安徽段的5个地点采集糜棱岩、超糜棱岩和千粒岩样品，进行40ar /39Ar年代学研究。其中大别造山带东缘3个地点的4个样品得出40ar /39Ar高原年龄为128 ~ 132 Ma；张巴林隆起西缘和蚌埠隆起东缘2个样品的40ar /39Ar高原年龄相同，均为120 Ma。等时线分析和其他证据表明，这些数据是可靠的。这些数据被解释为郯庐断裂带左旋走滑变形的冷却年龄。来自北方的较年轻的年龄可能与缓慢的走滑上升有关。这些结果表明，郯庐断裂带的大规模左移发生在早白垩世，而不是一些地质学家认为的晚三叠世（印支期）。因此，该断裂带不是大别造山带形成时期发育的转换断裂或缝合线，而是陆内扭断。
Samples of mylonite, ultramylonite and phyllonite were collected from 5 localities in the Anhui part of the Tan-Lu fault zone for40Ar/39Ar chronological studies. Among them 4 samples from 3 localities on the eastern margin of the Dabie orogenic belt yielded40Ar/39Ar plateau ages of 128 —132 Ma; and 2 samples from the western margin of the Zhangbalin uplift and eastern margin of the Bengbu uplift gave the same40Ar/39Ar plateau ages of 120 Ma. Isochron analyses and other lines of evidence suggest that the data are reliable. The data are interpreted as cooling ages of sinistral strike-slip deformation of the Tan-Lu fault zone. The younger ages from the north might be related to slower strike-slip rising. These results indicate that the large-scale left-lateral displacement in the Tan-Lu fault zone took place in the Early Cretaceous, rather than in Late Triassic (Indosinian) as proposed by some geologists. Therefore, this fault zone is an intracontinental wrench fault rather than a transform fault or suture line developed during formation of the Dabie orogenic belt.