湖南泥盆纪露头层序地层研究

湖南及相邻地区泥盆纪地层发育，其地层划分对比清楚，沉积类型丰富，地层裸露良好，是进行露头层序地层研究的理想场所。本文运用层序地层学的理论和方法，在详细的沉积学研究和精细的地层划分对比基础上，对湖南泥盆纪进行了精细的露头层序地层研究，详细阐述了层序建立和各种界面的露头标志，探讨了湖南泥盆纪的层序划分、海平面变化及全球对比，从而解释泥盆里各沉积层序的形成控制因素。

EXPOSURE SEQUENCE STRATIGRAPHY OF THE DEVONIAN STRATA IN HUNAN

This paper has focused on the research of the exposure sequence stratigraphy of theDevonian strata in Hunan based on the detailed sedimentological study and accurate stratigraphic division and correlation of the Devonian strata in Hunan. With the aid of the knowledge and theory of sequence stratigraphy, the characteristics of various boundary surfaces (including sequence surfaces and transgressive surfaces)and condensed sections aredescribed in detail. Three depositional sequences are divided for the Devonian strata in thestudy area in terms of the sequence boundary characterized by fluvial rejuvenation and palaeokarstification and condensed sections consisting of biostromes and tentaculitid--bearing thin-bedded siliceous rocks. Their times are represented by the late Emsian to early andmiddle Givetian,late Givetian to Frasnian and Famennian,respectively.The results of the depositional sequence study indicate that the Devonian strata in Hunan once experienced three cycles of sea-level rise and fall.