【摘要】 <正> 稀有气体同位素研究对了解地球早期历史、地幔一地壳的物质演化,地球的脱气和大气圈的形成,自然界核类的核转化过程以及同位素年龄测定等都具有重要意义。 本文主要讨论我国几个含油气盆地的天然气和石油伴生气中稀有气体氦、氩以及氮气的丰度分布特征和氩同位素Ar⁴⁰/Ar³⁶丰度比的变异。根据它们的成因类型,结合有关更多还原

【Abstract】 A hundred natural gas samples of different geological periods collected from Various localities were determined for their nitrogen, helium and ’argon contents, as well as the isotopie composition of argon. The range of Ar40/Ar36 ratio was found to be 305-9255. The helium-argon chronological formula for calculating natural gas age was corrected. Based upon’ the chronological accumulation effect of radiogenic argon-40, an argon-40-argon-36 empirical formula for calculating natural gas age has been proposed.It can be seen from the ratio of nitrogen to atmospheric argon that most of nitrogen in these natural gases could not be derived from atmospheric nitrogen, but elsewhere.The ’range of radiogenic He/Ar40 turn’s out to be 5.19 to 23.18, with the range between 7 to 14 for most samples. The He/Ar40 ratios of Sinian samples are in the range of 5.39 to 6.14, indicating their deep derivation from the earth,It should be noted that the Ar40/Ar36 ratio shows, a general trend of approaching the atmospheric value from the Sinian to the Tertiary Period, or from old to young in geological age, mirroring, to a great extent, the evolutionary tendency of the rare gas isotopie composition of natural gases with the continuous degassing of the earth.更多还原