To better understand the lithosphere mantle collision tectonics between the India plate and Asia plate, we determine three dimensional P wave velocity structure beneath western Tibet using 27,439 arrival times from 2,...To better understand the lithosphere mantle collision tectonics between the India plate and Asia plate, we determine three dimensional P wave velocity structure beneath western Tibet using 27,439 arrival times from 2,174 teleseismic events recorded by 182 stations of Hi-CLIMB Project and 16 stations in the north of Hi-CLMB. Our tomographic images show the velocity structure significantly difference beneath northern and southern Qiangtang, which can further prove that the Longmu Co-Shuanghu ophiolitic belt is a significant tectonic boundary fault zone. There are two prominent high velocity anomalies and two prominent low velocity anomalies in our images. One obvious high velocity anomalies subduct beneath the Tibet at the long distance near 34°N, whereas it is broke off by an obvious low velocity anomaly under the IYS. We interpret them as northward subducting Indian lithosphere mantle and the low velocity anomanly under IYS likely reflects mantle material upwelling triggered by tearing of the northward subduction Indian lithosphere. The other prominent high velocity anomaly was imaged at a depth from 50 km to 200 km horizontal and up to the northern Qiangtang with its southern edge extending to about 34°N through Hoh Xil block. We infer it as the southward subducting Asia lithosphere mantle. The other widely low velocity anomaly beneath the Qiangtang block lies in the gap between the frontier of India plate and Asia plate, where is the channel of mantle material upwelling.展开更多
As a deepening and extension of Theory of Unified Representation of Gravitational Field^([1]), this paper covers two aspects as follows: in theory, we go into the fundamental structure of the internal problem and put ...As a deepening and extension of Theory of Unified Representation of Gravitational Field^([1]), this paper covers two aspects as follows: in theory, we go into the fundamental structure of the internal problem and put emphasis on seeking the solution of the disturbing potential in spectral domain and establishing a spectral structure form of anomalous density; and in application, according to the given form we try to take a look at the distribution charateristics of anomalous densities of lithosphere about 30—40 km deep in the continent of China in illustration of evaluating practical trustworthiness of the present theory. Calculations done here are based on earth gravity model DQM84D^([2]) and show that this theory seems to be convincing.展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2016YFC0600301)the Geological Investigation Project of China Geological Survey(Grant No.DD20190448,DD20190370)the Natural Science Foundation of China(Grant No.41374101,4171101169,41274095)。
文摘To better understand the lithosphere mantle collision tectonics between the India plate and Asia plate, we determine three dimensional P wave velocity structure beneath western Tibet using 27,439 arrival times from 2,174 teleseismic events recorded by 182 stations of Hi-CLIMB Project and 16 stations in the north of Hi-CLMB. Our tomographic images show the velocity structure significantly difference beneath northern and southern Qiangtang, which can further prove that the Longmu Co-Shuanghu ophiolitic belt is a significant tectonic boundary fault zone. There are two prominent high velocity anomalies and two prominent low velocity anomalies in our images. One obvious high velocity anomalies subduct beneath the Tibet at the long distance near 34°N, whereas it is broke off by an obvious low velocity anomaly under the IYS. We interpret them as northward subducting Indian lithosphere mantle and the low velocity anomanly under IYS likely reflects mantle material upwelling triggered by tearing of the northward subduction Indian lithosphere. The other prominent high velocity anomaly was imaged at a depth from 50 km to 200 km horizontal and up to the northern Qiangtang with its southern edge extending to about 34°N through Hoh Xil block. We infer it as the southward subducting Asia lithosphere mantle. The other widely low velocity anomaly beneath the Qiangtang block lies in the gap between the frontier of India plate and Asia plate, where is the channel of mantle material upwelling.
基金Project supported by National Natural Science foundation of China
文摘As a deepening and extension of Theory of Unified Representation of Gravitational Field^([1]), this paper covers two aspects as follows: in theory, we go into the fundamental structure of the internal problem and put emphasis on seeking the solution of the disturbing potential in spectral domain and establishing a spectral structure form of anomalous density; and in application, according to the given form we try to take a look at the distribution charateristics of anomalous densities of lithosphere about 30—40 km deep in the continent of China in illustration of evaluating practical trustworthiness of the present theory. Calculations done here are based on earth gravity model DQM84D^([2]) and show that this theory seems to be convincing.
