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Qi S.-S.,China University of Geosciences | Qi S.-S.,Qinghai Geological Survey Institute | Qi S.-S.,Qinghai Prov Key Laboratory Of Geological Processes And Mineral Res Of Northern Qinghai Tibetan Plateau | Deng J.-F.,China University of Geosciences | And 6 more authors.
Geological Bulletin of China | Year: 2011

The only Early Cretaceous continental volcanic strata in Qinghai Province are distributed in Maixiushan area between Tongren County and Zeku County in Huangnan Prefecture of Qinghai Province and lie in Zeku subunit of West Qinling stratigraphic unit. Based on profile study and regional stratigraphic correlation, the authors newly named this suite of strata Early Cretaceous Maixiushan Group (K1M). The purplish red-grayish purple intermediate-basic volcanic rocks intercalated with sandy conglomerate in its lower part constitute the newly-built Duohemao Formation(K1d), which is a suite of typical continental fissure eruption alkaline basalt and continental red bed formation. The purplish red sandy conglomerate assemblage in the upper part of the Maixiushan Group remains called Wanxiu Formation(K1w), which is a suite of alluvial fan facies continental molasses formation. The two parts are obviously in conformable contact. According to the angular unconformity between Maixiushan Group and its overlying and underlying strata, the isotopic ages of volcanic rocks of Duohemao Formation and the insects, estherites and plant fossils in Wanxiu Formation, the authors hold that the Maixiushan Group was formed in Early Cretaceous. Distributed along the nearly NS-trending tensional faulting belt, the Maixiushan Group is of the intracontinental rift facies sedimentation which was produced in Early Cretaceous intracontinental environment and withered away in the same environment, and the formation of the Maixiushan Group indicated that the the West Qinling area entered into a regional extension stage in Early Cretaceous period. Source

Lin J.,Central South University | Lin J.,Bureau of Mineral Resources | Ding M.,Central South University | Tang J.-T.,Central South University | And 2 more authors.
Progress in Electromagnetics Research Symposium | Year: 2010

Based on the finite element method and Cole-Cole model, the paper studied the numerical simulation on dual-frequency IP method. First of all, the paper introduced the primary theory of the dual-frequency IP method and gave the boundary value problem and variational equations, then replaced the complex resistivity of the model with the Cole-Cole model's param- eters under ignoring the EM effect. Through solving the last linear equations, electric potentials of all the model's points were obtained. With changing model's parameters, we got different curves of the Fs and phases. Finally, according to the results of the simulations, the algorithm was proved to be correct and adaptable. Source

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