| Paleomagnetic studies were performed on four Phanerozoic sections in South China. These are: the Tangshan Paleozoic section in Jiangsu province, the Gechongwu Precambrian/Cambrian boundary section, a Middle Triassic formation, and Late Permian limestones in Guizhou province. A pervasive remagnetization, acquired at the time of Late Triassic/Jurassic folding has been observed throughout the Tangshan Paleozoic section, yielding a paleopole falling at 56N, 314E. A similar pole (70N, 309E) was also obtained from the Guizhou Triassic rocks. Three magnetization components were isolated from the Gechongwu Precambrian/Cambrian rocks, from which three paleopoles, 17S/239E, 32S/179E and 56N/247E, were calculated and interpreted to have late Sinian/early Cambrian (primary), and middle Paleozoic and Triassic directions, respectively. The characteristic magnetization of the Guizhou Permian limestones was identified to be secondary. It gives a paleopole of 34N, 208E, which appears to be latest Permian in age.; A review of paleomagnetic results published thus far for South China indicates that South China has experienced three major episodes of remagnetizations during the latest Permian, the Triassic, and the Late Triassic/Jurassic. All three remagnetizations show similar shallow inclinations but different declinations (east-northeasterly, north-northeasterly and northerly, respectively). SEM observations on magnetic minerals residing in the remagnetized rocks suggest that all the remagnetizations are chemical remanences possibly caused by the migration of fluids. The fluids responsible for the remagnetizations are inferred to have been expelled during a variety of tectonic events that affected the South China Block. These tectonic events include the closure of Paleo-Tethys to the west of South China, the activation of the Longmenshan overthrust faults and the subduction of the Pacific plate underneath Eurasia. Moreover, the geographic distribution of the remagnetized rocks, source rocks favorable for hydrocarbon generation, and the distribution of producing oil and gas fields indicate that the remagnetizations may be correlated with the migration of hydrocarbons in South China. This has important implications for future petroleum exploration in South China.; A new apparent polar wander path (APWP) can be constructed for South China by taking all the remagnetized poles into account. This APWP implies that the pre-Cretaceous tectonic evolutionary history of the South China Block was characterized by rapid northward motion during the early Paleozoic and large scale clockwise rotations during the late Paleozoic/Mesozoic. |
