| 华南陆块均衡重力状态及其地质意义 |
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| 关键词:South China block isostatic gravity anomaly isostatic depth anomaly earth dynamics |
| 基金项目:中国地质调查局地质调查项目(编号: DD20190012; DD20221643);国家自然科学基金项目(编号: 92062108; 42074099; 41630320) |
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| Isostatic Gravity State in South China Block and Its Geological Implication |
| Isostatic gravity is a universal geophysical phenomenon that can provide reference information for regional deep structure, lithospheric deformation, crustal structure, and stress field. It is one of the important methods to study the internal structure of the crust and divide tectonic units. The South China block is an important part of the Eurasian block and the “granary” of mineral resources in China. Although research on the South China block has been conducted for nearly 100 years, there are still great controversies regarding many geological issues. To understand the isostatic degree of the South China block and its influence on the structure and control of mineral resources, we investigated isostatic gravity and isostatic depth anomalies. The isostatic gravity anomaly was obtained using the satellite Bouguer gravity calculation, and then the isostatic depth anomaly was calculated using elevation and crust-mantle density contrast. We determined that the crust is isostatic in most regions of the South China block, and the relative positive isostatic anomalies are mainly distributed in the eastern coastal areas and Wuling Mountains. The relative negative isostatic anomalies reflected the orogenic activities in the Qinling–Dabie orogenic belt, Jiangnan orogenic belt, and western margin of the South China block. The transition or gradient zone with positive and negative isostatic depth anomalies is usually the deep structural transition zone, and earthquakes occur along these areas intensively, which should be the key areas of earthquake activity research. Isostatic gravity anomalies also indirectly constrain the distribution of different types of metal deposits. The positive isostatic gravity anomalies mainly produce mantle-derived metal deposits, whereas the negative isostatic anomalies mainly produce crust-derived metal deposits. |
| YAN Jia-yong,ZHANG Yong-qian,LUO Fan,SHE Jing-jin,JIANG Chang-xu,LIU Jia-hao.2022.Isostatic Gravity State in South China Block and Its Geological Implication[J].Acta Geoscientica Sinica,43(6):744-754. |
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