华南二叠-三叠系界线处的磁化率特征及其对比意义

SUSCEPTIBILITY AND ITS SIGNIFICANCE ACROSS THE PERMIAN-TRIASSIC BOUNDARY IN SOUTH CHINA

目前界线层型的确定多以生物标定 ,但在国际地层委员会二叠 -三叠系界线工作组确定的 4个二叠 -三叠系界线层型候选剖面中 ,生物地层界线却较难精确对比。因此 ,其他具有广泛对比意义的事件地层标志也被用来作为确定二叠 -三叠系界线的辅助标志。本文把磁化率特征(古气候的代用指标 )运用于二叠 -三叠系界线地层研究中 ,发现华南许多剖面上高精度的磁化率在二叠 -三叠系界线处具有同步的变化趋势 ,因而 ,磁化率特征可以作为二叠 -三叠系界线地层对比的辅助标志。

The current boundary stratotype is commonly marked by fossils, but at the four GSSP candidate sections on PTB proposed by the PTB working group, the biotic boundary can not be well correlated. So, other event stratigraphic markers with wide correlation potential were used as auxiliary standards in dividing the PTB. Susceptibility, the indicator of paleo climate, was used in our PTB study for the first time. The high precision susceptibilities across the PTB at many sections in South China change in the same trend, which can be taken as an auxiliary standard for PTB correlation.