滇黔桂盆地东北部泥盆系竹节石页岩时空分布与沉积特征OA北大核心CSTPCD

To explore the distribution features of the Devonian tentaculitic shales in the Northeastern Di-anqiangui Basin,as well as the relationship between the tentaculitoids and organic matter accumulation,this study analyzes the stratigraphic cyclicity in multiple outcrop sections such as Wu'ai,Dongfeng,Shanglinxi,Zhaisha,Lipu,and Guigang.Additionally,this paper also investigates the favorable pro-duction stages,spatial distribution features,changes in stratigraphic thickness,and microscopic features of the tentaculitic shales.The results show that the Devonian strata in the northeast parts of the Dian-qiangui Basin can be divided into 13 third-order sequences,with deep-water facies shales mainly devel-oped in SQ5-SQii.During the rising stage of the second-order sea-level fluctuation,the tentaculitic shales are mainly formed in the TSTs of third-order sequences(TST5-TST9).During the high-stand stage of the second-order sea-level fluctuation,the tentaculitic shales are mainly formed in the HSTs of third-order sequences(HST10-HST11).The spatial distribution of tentaculitic shales is controlled by syn-sedimentary fault zones,with relatively good extension along the direction of fault zones and poor exten-sion along non-direction of fault zones.The origin of organic matter in the tentaculitic shales are closely related to tentaculitoids.The enrichment degree of tentaculitoids may have a certain indicative effect on the organic matter abundance of potential organic-rich shales.This study provides an example of the role played by plankton in the process of organic matter accumulation in Northeastern Dianqiangui Basin.