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本文对四川北部旺苍-南江地区晚侏罗世蓬莱镇组进行了较为详细的岩石磁学和古地磁学研究．逐步热退磁揭示出蓬莱镇组岩石所携带的剩磁由两个分量组成，其中低温组分（次生剩磁）的解阻温度低于420℃;高温组分（特征分量）可通过褶皱及倒转检验，由此求得磁偏角和磁倾角分别为18．4°和29．3°（构造校正后），95％置信回（α95）为8．5°，对应的古地磁极经纬度分别为236．4°E和66．6°N．基于古地磁结果，并结合已有的地质证据，提出根据古地磁学确定的扬子地块晚侏罗世古纬度偏低的原因可能是由真极移造成的．
In this paper, we carried out a more detailed study of rock magnetism and paleomagnetism in the Penglaizhen Formation of the Late Jurassic from Wangcang to Nanjiang in northern Sichuan. The gradual thermal demagnetization reveals that the remanence carried by the rocks in Penglaizhen Formation is composed of two components, of which the de-blocking temperature of the low-temperature component (secondary remanence) is lower than 420 ℃; the high-temperature component (characteristic component) The results of the inversion test show that the declination angle and the dip angle are respectively 18.4 ° and 29.3 ° (after structure correction) and the 95% confidence level (α95) is 8.5 °. The latitudes and longitudes of the corresponding paleomagnetic poles are respectively At 236.4 ° E and 66.6 ° N. Based on the paleomagnetic results and the existing geological evidences, it is suggested that the reason that the paleoclimate of the Late Jurassic in the Yangtze block, which is determined according to paleomagnetism, may be caused by the true pole migration.