Carbon, Oxygen, Strontium Isotope Characteristics and Cause Analysis of Carboniferous Carbonate Rocks in the Eastern oft-com:office:smarttags" />Sichuan Basin

详细信息   

• 责任者：Wang Kun (College of Geosiences ; China University of Petroleum (Beijing) ; Beijing 102249 ; China) ; Li Wei
• 刊名：Geochimica
• 出版年：2011
• 卷期：40(4)
• 关键词：碳酸盐岩 ; carbonate rocks ; 碳同位素 ; carbon isotopes ; 氧同位素 ; oxygen isotopes ; 锶同位素 ; strontium isotopes ; 四川 ; Sichuan Province
• 页码：p.351-362
• 图表：6 illus., 3 tables, 44 refs.
• 分类号：0600
• 出版序号：1619
• issnNo：ISSN0379-1726
• isbnNo：CN44-1398/P

摘要

///The validity of the samples was tested using trace elements and carbon and oxygen isotopes.Carbon,O and Sr isotope data of least altered Carboniferous carbonate rock in the eastern Sichuan Basin were processed.The C,O,and ⁸⁷Sr/⁸⁶Sr isotope characteristics,and paleosalinity and paleotemperature of different stratigraphic framework and different lithology were compared,aiming at better constraints on the diagenetic environment of carbonate rocks.The results suggest that it is mainly gypsic saline lake and sabkha environment when lowstand system tract(LST) deposited.The climate was hot and dry,terrestrial source fresh water was limited on impacting the diagenesis,anti-gypsumization and anti-dolomitization cause secondary limestone,with "wire cages" structures developed.When transgressive system tract(TST) deposited,it was mainly semi-limitated or limitated shelf environment.⁸⁷Sr/⁸⁶Sr value suggests that the impact on diagenesis from terrestrial source freshwater was enhanced,with dolomite well developed.It was mainly shelf environment when highstand system tract(HST) deposited,sediments were marine limestone,with mantle source Sr increased,indicating sea level rise,with 2011 年 significantly reduced terrestrial source Sr.Dolomite C,O,and Sr isotopes show big differences indicating four kinds of sedimentary environments:(1) freshwater sedimentary environment with low salinity;(2) intermediate-shallow burial marine environment;(3) marine and low temperature evaporation lagoon environment;(4) high-temperature environment with the highest temperature.Combined with ⁸⁷Sr/⁸⁶Sr and petrological characteristics,it is concluded that there are four kinds of dolomitizations: freshwater,buried,penecon-temporaneous,and hydrothermal dolomitizations in the eastern Sichuan Basin.