四川盆地南北缘志留纪Ⅲ型干酪根及其地质意义

The Silurian type Ⅲ kerogen from the northern and southern margins of the Sichuan Basin and its geological significance

关键词:  Ⅲ型干酪根  维管植物  四川盆地南北缘  早志留世

Key words:  type Ⅲ kerogen  vascular plant  northern and southern margins of the Sichuan Basin  Early Silurian

摘要:

从四川盆地南北缘近古陆的下志留统中所获干酪根显示,主要以Ⅱ型为主,其中含有管胞、木质素、纤维素等维管植物成分,而在盆地内的远离古陆地区干酪根则表现出以Ⅰ型为主。据此不仅说明在早志留世早期本区古陆上已出现有维管植物,而且进一步证实环境因素对植物演化具有重要影响。

Abstract:

The analysis of the kerogen from the marine environments on the northern and southern margins of the Sichuan Basin shows that the type Ⅲ kerogen,which comprises the vascular plant compositions such as tracheid,lignin and cellulose,occurs in large quantities in the Lower Silurian strata near the old land,whereas type Ⅰ kerogen has been found in the areas far away from the old land. The findings suggest that the vascular plants began to land in the study area even early in the Ordovician when the old land came into being,and abounded during the early Early Silurian,and that the environmental conditions may have exerted an important influence on the evolution of the plants.