摘要
川滇黔桂地区石炭系地层发育 ,其地层划分对比清楚 ,沉积类型丰富 ,地表露头良好 ,是进行层序地层研究的理想场所。本文运用层序地层学的理论和研究方法 ,在详细的沉积学研究和精细的地层划分对比基础上 ,对川滇黔桂地区石炭系地层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 ,探讨了川滇黔桂地区石炭系地层的层序划分、层序区域对比。在此基础上 。
The Carboniferous strata extensively distributes in Sichuan,Yunnan,Guizhou and Guangxi provinces. It has the characteristicse of clear stratigraphic division and correlation, plentiful sediment types and better outcrops. It is suitable to have the sequence stratigraphy research in these areas. This paper has focused on the accurate researches of the exposure sequence stratigraphy of the Carboniferous strata based on the detailed sedimentological study and accurate stratigraphic division and correlation of the Carboniferous strata in Sichuan,Yunnan,Guizhou and Guangxi provinces with the aid of the theory and studying means of the exposure sequence stratigraphy. Sequences are divided mainly by the characteristics of the key boundary surfaces,regional correlation,sedimentary facies sequence changes,parasequence stacking patterns,facies assemblage and sedimentary geochemistry. It has expounded in detail the outcrop signs of the sequence division and various boundary surfaces. The Carboniferous strata in the study area are divided into 10 third\|scale sequences, which are named from sequence 1 to 10, with the upper series of Carboniferous strata having 5 sequences and the lower series also. In the lower series of Carboniferous strata, Yanguan stage are composed of sequence 1 to 2, and Datang stage from sequences 3 to 5. In the upper series, Huashiban stage are composed of sequence 6 and Dala stage of sequence 7, and Maping stage from sequence 8 to 10. According to the features of the bottom boundary surface, 10 sequences are classified into two sorts of sequences, which are type Ⅰ sequence (S\-1,S\-3,S\-6,S\-9,S\-\{10\}) and type Ⅱ sequence(S\-2,S\-4,S\-5,S\-7,S\-8). The bottom boundary surfaces of type Ⅰ sequence all have clear signs including the strong paleokarst,the different thickness eluvial facies,the strata discontinutity,the immense changes of sedimentary patterns and traits,the regional revival of river,the disappearence and abrupt changes of organism evolution and the huge and sudden alternation of carbon,oxygen and strontium isotope values. On the other hand, the bottom boundary surfaces of type Ⅱ sequence are character ized by the transient exposure,the weak erosion and the lithoface texture transformation. So it is discerned more difficultly than the bottom boundary surface of type Ⅰ sequence. This paper also has expounded in detail the sedimentary features of the first transgressive surfaces and condensed sections of sequences in the different sedimentary environments and basins. It has summarized the sedimentary characteristics of the different system tracts in the different facies and basins. On the basis of these researches, this paper has probed the sequence correlation in the different sedimentary facies and basins from the ways of the sequence numbers,boundary surface traits and system tract structures and has founded the time\|space pattern diagram of the Carboniferous sequence strata in the study area.
出处
《沉积学报》
CAS
CSCD
北大核心
2000年第2期190-197,共8页
Acta Sedimentologica Sinica
关键词
层序地层
时空格架
石炭系
川滇黔桂地区
sequence stratigraphy time-space pattern Carboniferous Sichuan,Yunnan,Guizhou and Guangxi provinces
