论文部分内容阅读
对取自赣南地区10个温泉的地热气体进行了气体化学成分及氦、碳、氖同位素组成的分析。该区地热气体可分为CO_2型和N_2型两种类型。CO_2型地热气体分布在赣南东南部地区,主要成分是CO_2,占总体积96.47%以上,二氧化碳气体的δ~(13)C值为-5.50‰~-3.49‰(PDB),平均为-4.66‰,为幔源无机成因;其氦同位素组成为1.36~2.27R_a,具有明显的幔源成因特征,最高约有28.2%的氦源于地幔;其N_2-Ar-He关系研究表明,该型地热气体中的氮源于地幔—地壳—大气混合成因。研究揭示该区CO_2型地热气体属幔源无机成因气,是地幔脱气作用的产物。N_2型地热气体分布在赣南西部地区,N_2含量占91.04%以上,其中二氧化碳气体的δ~(13)C值为-23.7‰~-12.6‰,平均为-17.82‰,为壳源有机成因;其氦同位素组成为0.06~0.13 R_a,具有明显的壳源放射性成因特征;~3He/~4He与~4He/~(20)Ne关系和He-Ar-N_2关系研究表明,N_2型温泉气主要来源于大气,并有壳源气体的贡献。
The chemical composition of gas and the composition of isotopes of helium, carbon and neon in geothermal gas collected from 10 hot springs in southern Jiangxi were analyzed. The geothermal gas in this area can be divided into CO_2 type and N_2 type two types. The CO_2 type geothermal gas is distributed in the southeastern part of southern Jiangxi Province, with CO 2 accounting for 96.47% of the total volume and δ 13 C value of carbon dioxide ranging from -5.50 ‰ to -3.49 ‰ (PDB) with an average of -4.66 ‰, which is the mantle-derived inorganic origin. The helium isotopic composition is 1.36-2.77 R_a, with obvious mantle source genetic features, and the highest about 28.2% of the helium is derived from the mantle. The N_2-Ar-He relationship shows that this type of geothermal Nitrogen in gas originates from mantle-crust-atmosphere mixing. The study reveals that the CO 2 geothermal gas in this area belongs to the mantle-derived inorganic gas, which is the product of the degassing of the mantle. The N_2 type geothermal gas is distributed in the western part of southern Jiangxi, accounting for 91.04% of the N_2 content. The δ 13 C value of carbon dioxide gas is -23.7 ‰ ~ -12.6 ‰, with an average of -17.82 ‰, which is the organic origin of the crust. The helium isotopic composition is 0.06 ~ 0.13 R_a and has obvious characteristics of shell-derived radioactive origin. The relationship between ~ 3He / ~ 4He and ~ 4He / ~ (20) Ne and He-Ar-N_2 shows that the main source of N_2 hot spring In the atmosphere, and the contribution of the shell source gas.