| 青藏高原东南缘新生代地壳运动的转换 |
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| 引用本文：裴军令,仝亚博,蒲宗文,景先庆,蔡瑜杭,李建锋.2019.青藏高原东南缘新生代地壳运动的转换[J].地球学报,40(1):106-116. |
| DOI：10.3975/cagsb.2018.112001 |
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| 基金项目:中国地质调查局地质调查项目(编号: DD20160268);中国地质科学院基本科研业务费项目(编号: JYYWF20182102));国家自然科学基金项目(编号: 41572183) |
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| 中文摘要:在青藏高原东南缘保山地体东部上新世营盘组玄武岩中开展的古地磁学研究, 获得了可靠的高温剩磁分量。地层校正后的特征剩磁分方向为Ds=166.5o, Is= –19.3o, k=41.9, a95=5.1o, N=22(采点)。褶皱检验显示其为原生特征剩磁分量。上新世古地磁数据显示, 保山地体东部区域自上新世以来相对于东亚构造稳定区古地磁参考极发生了14.5o±4.8o的逆时针旋转运动。虽然保山地体东部上新世的逆时针旋转运动与保山地体其它区域古近纪至中新世的顺时针旋转变形截然相反, 但是其与畹町走滑断裂和南汀河走滑断裂上新世以来的左旋走滑运动相吻合。本次研究通过保山地体和腾冲地体内部新生代古地磁数据及地体边界构造带活动演化的综合分析, 指出自古近纪早期印度板块与欧亚大陆初始碰撞以来, 青藏高原东南缘腾冲地块和保山地体在渐新世末期至早中新世时期, 以及上新世早期分别发生了地壳运动方式的转换。保山地体地壳的运动学方式直接控制了地体边界走滑断裂的构造演化过程。 |
| 中文关键词:青藏高原东南缘 保山地体 上新世 古地磁 旋转变形 |
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| The Cenozoic Multi-stage Transform of Crustal Movement Pattern of the Southeastern Edge of the Tibetan Plateau |
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| Abstract:High-temperature magnetic components were obtained from the Pliocene Yingpan Formation basalt of the Baoshan Terrane at the southeastern edge of the Tibetan Plateau. The tilt-corrected site-mean direction is Ds=166.5o, Is= –19.3o, k=41.9, a95=5.1o, N=22 (sampling sites), and the positive multi-type fold tests provide their primary magnetic origin. The Pliocene paleomagnetic data indicate that the eastern part of the Baoshan Terrane has experienced 14.5o±4.8o of counterclockwise rotational deformation since the Pliocene, relative to East Asia, which is opposite to that of the northern and central part of the Baoshan Terrane. Combined with the Cenozoic paleomagnetic data of the Baoshan Terrane and Tengchong Block and the activity of block boundary faults, the authors hold that, since the collision of the India plate with the Eurasia plate in the Paleocene, the crustal movement pattern of the Tengchong Block and Baoshan Terrane experienced transforms in late Oligocene and early Miocene, and early Pliocene, respectively, which controlled the tectonic evolution of the strike-slip faults surrounding and in the Baoshan Terrane. |
| keywords:southeastern edge of the Tibetan Plateau Baoshan Terrane Pliocene paleomagnetism rotational deformation |
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