摘要
济阳坳陷CO2气藏主要发育在高青-平南深断裂中南段和阳信次级凹陷西北缘及商店火山岩穹隆构造内。气藏中CO2气体浓度为69%~97%,δ13CCO2值为-5.67‰^-3.35‰,CH4/3He值为(1.01~5.65)×108,3He/4He值为(2.80~4.49)×10-6,即R/Ra为2.00~3.21,40Ar/36Ar值为317~1791,CO2/3He值为(0.25~2.61)×109。以上地球化学数据表明,济阳坳陷气藏中CO2主要来源于地幔,且幔源CO2在成藏过程中有损失,或者有壳源CO2的加入,特别是部分碳酸盐岩变质成因CO2的加入。在对CO2气来源定性分析的基础上,还需要在各来源的定量区分和CO2气藏的成藏及其与岩浆活动的时空匹配关系等方面作进一步的研究。
The CO2 gas pools of the Jiyang Depression are mainly located in the central and southern parts of the Gaoqing-Pingnan deep fault zone, Northwestern margin of the Yangxin subsidiary depression and the Shangdian volcanic dome. These CO2 gas pools contain 69%- 97% CO2. The geochemical analyses indicate that the δ^13CCO2 values are varied from -5.67‰ to -3.35‰, the CH4/^3He ratios are varied from 1.01×10^8 to 5.65×10^8, the ^3He/4He ratios are varied from 2.80×10^6 to 4.49×10^-6（ i.e. R/Ra= 2-3.21）, the ^40Ar/^36Ar ratios are varied from 317 to 1791, and the CO2/^3He ratio are varied from 0.25×10^9 to 2.61×10^9 respectively. The data above consistently suggest that the CO2 reserved in the Jiyang Depression was mainly sourced from the mantle, with possible influence of partly loosing CO2 in the upward migration process of the mantle sourced CO2, or possible mixing with small part of crust sourced CO2 gases such as the CO2 produced from metamorphism of carbonate rocks. Besides the qualitative analysis of the CO2 source, many other research works, such as the quantitative analysis of CO2 sources, the forming process of CO2 gas pools and its relationship to the magmatic activities, should be further undertaken.
出处
《矿物岩石地球化学通报》
CAS
CSCD
2006年第3期272-278,共7页
Bulletin of Mineralogy, Petrology and Geochemistry
基金
国家自然科学基金资助项目(40425006
40352003)
中国科学院地球化学研究所百人计划资助项目
