| 塔里木地块侏罗、白垩纪的古地磁 |
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| 引用本文： | 张正坤,李永安.塔里木地块侏罗、白垩纪的古地磁[J].地震地质,1989,11(3):9-16. |
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| 作者姓名： | 张正坤 李永安 |
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| 作者单位： | 中国地质科学院地质研究所
(张正坤)，新疆地质矿产局地质研究所
(李永安，李强)，中国地质大学研究生部
(翟永建)，美国斯坦福大学地球物理系
(李燕平，Michael McWilliams，Allan cox)，美国斯坦福大学地球物理系(Robert sharps) |
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| 摘 要： | 本文对塔里木地块西北缘库车、拜城一带中新生代剖面进行了古地磁研究。库车与拜城两剖面具有不同方向产状,经产状校正之后,均为同一方向,表明磁性是在第三系褶皱之前获得的。热退磁结果表明500℃之前为现代地磁场方向,解阻温度为675℃,说明磁性载体为赤铁矿。 古地磁结果表明,塔里木地块在晚侏罗—晚白垩世之间没有经历大规模的构造运动。有可能自晚白垩世之后相对西伯利亚地块向北东方向移动过
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| 关 键 词： | 塔里木地块 侏罗 白垩系 古地磁 |
JURASSIC AND CRETACIOUS PALEOMAGNETISM OF THE TARIM BLOCK |
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| Zhang Zheng-kun.JURASSIC AND CRETACIOUS PALEOMAGNETISM OF THE TARIM BLOCK[J].Seismology and Geology,1989,11(3):9-16. |
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| Authors: | Zhang Zheng-kun |
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| Abstract: | Two Mesoxoic sections along the northern margin of the Tarim block of China were studied paleomagnetically. One Late Cretaceous redbed section of 180 meters, lying 100 km north of Kuche (lat. =41.5°N, long. =83.5°E)gives a mean paleomagnetic pole position at lat.=63.0°, long. = 210°(N = 5, α95 = 16°). The two lower sites within the section show reversed magnetic polarity. Another Late Jurassic to Early Cretacious sandstone section of 75 meters, lying northwest of Baicheng (lat.=41.8°N, long. =82°. E), yields a mean paleomagnetic pole at lat. =65°, long. =:209°(N = 6, α95 = 9°.). Although the poles from two sections are significantly different before tilt corrections, they become superimposed each other after tilt corrections, suggesting a positive fold test at 99% confidence level. Thermal demagnetization experiments remove the present earth field components in temperature ranges before 500℃ and exhibit unblocking temperatures around 675℃, indicating the main magnetic mineral in sample |
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| Keywords: | Tarim block Jurassic Cretacious Paleomagnetism |
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