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研究区的碳氧同位素组成表明 ,矿化灰岩和细晶灰岩的δ13C为正值 ,其δ18O值变化于- 6.4‰～ - 2 1‰之间 ;而绝大多数矿石中碳酸盐矿物的δ13C为负值 ,只有少数为正值 ,与其对应的δ18O值为 - 12 .3‰～ - 2 1.5‰。根据δ13C -δ18O图解分析 ,区分出了 3种不同类型的碳同位素 :( 1)三叠纪海洋生物碳 ;( 2 )海相碳酸盐的碳与热卤水中碳的过渡类型 ;( 3)深部热卤水中CO2的碳。研究发现矿化灰岩和结晶灰岩中的碳是热卤水中所携带的无机碳交代海洋碳的结果 ,而矿石中碳酸盐矿物的碳则是深部热卤水中所携带的无机碳。结果表明这些无机碳可能主要来自地壳深部地幔去气作用释放出来的地幔碳。
The composition of carbon and oxygen isotopes in the study area shows that the δ13C value of mineralized limestone and fine-grained limestone is positive, and the δ18O value varies between -6.4 ‰ and -21 ‰, while most of the minerals in the carbonate minerals Δ13C is negative, only a few positive values, and its corresponding δ18O value of - 12 .3 ‰ ~ - 2 1.5 ‰. Three different types of carbon isotopes are distinguished according to the graphical analysis of δ13C-δ18O: (1) Triassic marine biochar; (2) transition type of marine carbonates to carbon in hot brine; (3) Carbon dioxide in deep hot brine. It is found that the carbon in mineralized limestone and crystalline limestone is the result of the replacement of marine carbon by the inorganic carbon carried in the hot brine and the carbon in the mineral carbonate is the inorganic carbon carried in the deep hot brine. The results show that these inorganic carbons may be mainly derived from the mantle carbon released from the deep mantle degassing in the crust.