南海西南部万安盆地构造圈闭样式分析

STUDIES ON THE MAGNETIC FABRIC CHARACTERISTICS OF INDEX BED AND THE PALEOENVIRONMENTAL SIGNIFICANCE

在研究区域构造地质、沉积地层和盆地演化历史的基础上，把万安盆地形成的构造圈闭划分为压缩、伸展和剪切等三种基本构造样式，并对各类型构造样式及其成因机制作了分析和探讨。

The indicative feature,obtained by the measurement and statistic analysis on the magnetic fabric of the buried paleosol and modern tidal flat deposit at the Yangtze River Delta and the vicinity,of the flood plain deposit at the lower reaches of the Yangtze River,and of the eolian dune at Zhoushan beach and the loess sequence at Nanjing,shows that the eolian dune at Zhoushan beach is similar to the loess sequence at Nanjing in medium energy phase field of transportation,but clearly different in provenance,and that modern tidal flat deposit and flood plain deposit are completely different from the two types of deposit above both in medium energy phase field of transportation and provenance.However,flood plain deposit and Nanjing loess have many similarities in provenance.Medium energy phase field and provenance of the buried paleosol are similar to tidal flat deposit,but greatly different from the eolian deposit at Nanjing and Zhoushan.These reveal that parent deposit of the buried paleosol have no relationship with wind medium but with water medium in transportation and provenance.