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对广东黄坌剖面早三叠世大冶组122个岩芯样品的岩石磁学和古地磁研究表明,样品的载磁矿物以含钛的磁铁矿为主.热退磁显示2~3组分量.低温分量与现代地磁场方向一致,100~400℃分离出一组叠加剩磁,为燕山期的重磁化.400~530℃退磁区间获得稳定的特征剩磁(层面坐标下D=51.1°,I=15.3°,α95=5.0°),并通过了广义的褶皱检验和倒转检验,表明高温分量为原生剩磁.对应虚磁极位置:38.5°N,212.7°E,dp=2.6,dm=5.1.它与扬子地块同时代的极位置在95%的置信区间内重叠,表明在早三叠世时,南华地块与扬子地块已经拼贴.已发表的南华地块上的早三叠世古地磁数据表明,它们的磁倾角接近,但偏角变化较大,在投影图上早三叠世古磁极分布于一个以南华地块为中心的小圆上,暗示了中国南方广泛存在的局部旋转导致各地的古地磁极不一致.
The rock magnetism and paleomagnetism of 122 core samples of the Early Triassic Daye Formation in the Huangpi Section of Guangdong Province show that the magnetite-bearing minerals are dominated by titanium-bearing magnetite, and thermal demagnetization shows that 2 to 3 components . The low temperature component is consistent with the direction of modern geomagnetic field, and a set of superimposed remanences are separated out at 100-400 ℃ for the remagnetization of Yanshanian period.The stable remanent magnetization (D = 51.1 °, I = 15.3 °, α95 = 5.0 °), and passed the generalized fold test and inversion test, indicating that the high temperature component is the primary remanence. The corresponding virtual magnetic pole position is 38.5 ° N, 212.7 ° E, dp = 2.6, dm = 5.1 It coincides with the contemporaneous polar position of the Yangtze block within 95% confidence intervals, indicating that during the Early Triassic the South China block and the Yangtze block had been collapsed.The published Triassic on the South China block The paleoclimate data show that their magnetic dip angle is close but the declination angle changes greatly. On the projection map, the ancient magnetic poles of the Early Triassic distributed on a small circle centered on the Nanhua block, suggesting the widespread local rotation in southern China As a result, the ancient geomagnetic poles in different places are extremely inconsistent.