• 责任者：Li Pengchun (Key Laboratory of Marginal Sea Geology ; South China Sea Institute of Oceanology ; Chinese Academy of Sciences ; Guangzhou 510301 ; China) ; Chen Guanghao
• 刊名：Acta Sedimentologica Sinica
• 出版年：2011
• 卷期：29(5)
• 关键词：白云岩 ; dolostone ; 塔里木盆地 ; Tarim Basin
• 页码：p.842-856
• 图表：7 illus., 3 tables, 26 refs.
• 分类号：0803
• issnNo：ISSN1000-0550
• isbnNo：CN62-1038/P

Lower Ordovician dolomites in the central Tarim Basin are of various types and extensively distributed. Seven dolostone types could be documented. It’s characterized by middle-high δ¹⁸O negative value (-3.2%～-8.7‰), low-middle δ¹³C negative value (-3%～-0.77‰), and high Z value of 118～123. Most diagenetic temperature calculated by empirical formulas using δ¹⁸O values are between 118 to 123 ℃, which indicates that these kind of dolomite belongs to low temperature dolostone. These dolomites have also characteristics of low Mg/Ca and variable Fe/Mn ratio values. According to mineral composition, dolomite monomineral can be divided into high Fe content and low Fe content species.⁸⁷Sr/⁸⁶Sr ratios of most samples are low(among 0.708 8～0.709 7). These characteristics reveal that the origin of dolomite in the study area can be classified into penecontemporaneous dolomitization and burial dolomitization. According to Ordovician palaeogeographical evolution, the penecontemporaneous dolomitization arised in the seafloor environment, mainly in tidal flats or beach environment. And this kind of dolomite is characterized by low diagenetic temperature, low ⁸⁷Sr/⁸⁶Sr ratios, and low Fe content dolomite minerals.The burial dolomitization can be interpreted by two diagentic models.