• 责任者：Cai Junjun (Institute of Geology ; Chinese Academy of Geological Sciences ; Beijing 100037 ; China) ; Lu Zhenquan
• 刊名：Geoscience
• 出版年：2013
• 卷期：27(6)
• 关键词：天然气水合物 ; gas hydrates ; 碳酸盐矿物 ; carbonates ; 祁连山 ; Qilian Mountains
• 页码：p.1356-1364
• 图表：5 illus., 1 table, 52 refs.
• 分类号：1003
• issnNo：ISSN1000-8527
• isbnNo：CN11-2035/P

     It is a universal phenomenon for gas hydrate associated carbonates in seafloor sediments,but it is rarely reported in the permafrost.Based on microscopic observations and mineral analyses on carbonates associ-ated with gas hydrate,mineral species and occurrence modes of carbonates are determined in the Qilian Moun-tain permafrost.The results show that occurrence modes of carbonates can be divided into four types according to mineral compositions and geological features.Characteristics of C and O isotopes in different occurrence modes of carbonates indicate that the smoky gray rhombic calcite crystals or microcrystalline calcites may be re-lated to gas hydrate decomposition.The variation of C and O isotopic compositions in carbonates with depth sug-gests that there probably exist hydrocarbon seepage activities within a certain depth,namely decomposition of gas hydrate,resulting in carbonate formation.