海拉尔盆地与澳大利亚Bowen-Gunnedah-Sydney盆地系片钠铝石碳来源的比较研究  

Comparative study of carbon origin of dawsonite between Hailar Basin of China and Bowen-Gunnedah-Sydney basin system of Australia

作　　者：高玉巧[1] 刘立[1] 蒙启安[2] 许岩[1] 曲希玉[1] 金仙梅 

机构地区：[1]吉林大学地球科学学院,吉林长春130061 [2]大庆油田有限责任公司勘探开发研究院,黑龙江大庆163712 [3]中石化西北分公司勘探开发研究院,新疆乌鲁木齐830011

出　　处：《世界地质》2005年第4期344-349,共6页World Geology

基　　金：国家自然科学基金"岩浆成因二氧化碳气藏中储集砂岩的热对流成岩作用("40372060);国家油气专项"大庆探区外围中新生代断陷盆地群演化和油气远景("XQ-2004-07)资助

摘　　要：作为胶结物、交代物或孔洞充填物,片钠铝石[NaAlCO(3OH)2]大量发育于海拉尔盆地和澳大利亚BGS盆地系。根据片钠铝石稳定同位素组成,对比分析片钠铝石的碳来源。BGS盆地系片钠铝石的1δ3C分布连续,分布区间为-4.0×10-3～4.1×10-3,计算出的与片钠铝石平衡的CO2气的1δ3CO2值分布区间为-11.3×10-3～-4.6×10-3,结合片钠铝石的分布和区域地质背景,认为片钠铝石中的碳来源于岩浆活动而带来的无机CO2气;海拉尔盆地片钠铝石1δ3C值分布连续,为-4.64×10-3～2.12×10-3,计算出的与片钠铝石平衡的CO2气的1δ3CO2值分布区间为-11.82×10-3～-5.11×10-3,结合海拉尔盆地探井中未钻遇碳酸盐地层、含片钠铝石井和幔源CO2气井分布相吻合且位于燕山期花岗岩区或其附近的深大断裂带上,认为形成片钠铝石所需的CO2气为与燕山期岩浆作用有关的幔源CO2气,片钠铝石形成时因油气充注而介入少量生物成因碳。Dawsonite, NaAlCO3 （OH） 2, is widespread as a cement, replacement, and cavity filling in Hailar Basin of China and Bowen-Gunnedah-Sydney basin system of Australia. The origin of dawsonite is emphatically contrasted and analyzed by stable isotope composition of dawsonite. Dawsonite δ^13C values ranging from -4.0 × 10^-3 to 4.1 × 10^-3 are remarkably consistent through the Bowen-Gunnedah-Sydney basin system. The calculated δ×13C values of CO2 gas in isotope equilibrium with dawsonite are ranging from - 11.3 ×10-3 to -4.6 ×10^-3. These values indicate that the carbon of dawsonite comes from inorganic CO2 gas accompanied by magmatic activity. While, in Hailar Basin the dawsonite δ^13C values ranging from -4.64 × 10^-3 to 2.12 × 10^-3 are remarkably consistent. The calculated δ^13C values of CO2 gas in isotope equilibrium with dawsonite range from - 11.82 × 10^-3 to - 5.11 × 10^-3. According to the coincidence of dawsonite-containing well and CO2 gas well with mantle source, lying along deep fracture within or adjacent to Yanshan granite, it is concluded that CO2 gas forming dawsonite is derived from mantle related to magmatic process during of the Yanshan Stage. A little biologic origin carbon owing to petroleum charging intervened when dawsonite formed.

关 键 词：片钠铝石 同位素组成 碳来源 海拉尔盆地 Bowen-Gunnedah-Sydney盆地系 

分 类 号：P578.6[天文地球—矿物学]