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在自然界中,氖有3个稳定同位素:~(20)Ne,~(21)Ne和~(22)Ne.其中,由于放射性核反应,如~(18)O(n,a)~(21)Ne和~(19)F(n,a)~(22)Ne等引起相对于大气组成~(21)Ne和~(22)Ne的富集.在大洋中脊玄武岩(MORB)和洋岛玄武岩(OIB)等幔源物质中,发现的~(20)Ne过剩被认为是地幔中太阳风型氖的存在,代表着地球原始组成.由于上、下地幔脱气程度的差异,而导致其He/U和Ne/U比值的不同.然而,对于大陆地幔的稀有气体特征尚没有得到清楚的认识.近来,Dunai和Baur观测到欧洲次大陆地幔相对于海洋地幔富集放射性成因~4He,并将此归因于欧洲次大陆地幔的富集.中国东部由于中新生代拉张,沿郯庐断裂带喷发了大量新生代火山岩和幔源包体,其微量元素、稀土同位素组成的研究表明,东部地幔具有EMⅠ和EMⅡ特征.本文试图以天然气中氖同位素组成作为示踪剂对东部富集地幔作进一步探讨.1 样品及实验本文中30个天然气样品采集于东部5个沉积盆地(松辽、辽河、渤海湾、苏北和三水)气体类型包括二氧化碳、烃类和二氧化碳-甲烷-氮气混合气等.天然气藏储层为松辽盆地的白垩系,其他盆地的以第三系为主,深度从近地表到5000m深.在实验室内,利用全金属高真空系统,首先将氖与活性气体(如烃类、二氧化碳和氮气等)和其他稀有气体进行分离,然后将其导入V
In nature, there are three stable isotopes of Ne: ~ (20) Ne, ~ (21) Ne and ~ (22) Ne. Among them, due to the radionuclide reaction, Ne and ~ (19) F (n, a) ~ (22) Ne and so on are responsible for the enrichment of ~ (21) Ne and ~ (22) Ne relative to the atmospheric composition.MATERIALS OF MORB AND YANGTZE BASALT OIB) and other mantle-derived materials, the excess of ~ (20) Ne is found to be the presence of solar-type neon in the mantle, representing the original Earth’s composition. Due to the difference in degassing levels between the upper and lower mantle, the He / U And Ne / U ratios.However, there is no clear understanding of the rare gas characteristics of the continental mantle.Dunai and Baur recently observed the radiogenic genesis ~ 4He of the continental submarine mantle relative to the marine mantle, and attributed this In the eastern part of China, due to the extension of Mesozoic and Cenozoic, a large amount of Cenozoic volcanic rocks and mantle-derived inclusions erupted along the Tan-Lu fault zone. The study of trace element and rare earth isotopic composition of the eastern mantle shows that there are EMⅠ and EM Ⅱ characteristics.This paper attempts to use Neon isotope composition of natural gas as a tracer to further explore the enrichment of the mantle in the eastern region.1 samples and experiments In this paper, 30 Gas samples collected in the eastern five sedimentary basins (Songliao, Liaohe, Bohai Bay, North Jiangsu and Sanshui) gas types include carbon dioxide, hydrocarbons and carbon dioxide - methane - nitrogen gas mixture, etc. Natural gas reservoir for the Songliao Basin Of the Cretaceous, the other basins dominated by Tertiary, depth from the surface to 5000m deep.In the laboratory, the use of all-metal high-vacuum system, first of all, neon and reactive gases (such as hydrocarbons, carbon dioxide and nitrogen, etc.) And other rare gas separation, and then import it into V.