渤海湾盆地黄骅拗陷天然气中幔源氦  

MANTLE HELIUMOF NATURAL GASES FROM HUANGHUA DEPRESSION IN BOHAI GULF BASIN

作　　者：戴春森[1] 戴金星[1] 宋岩[1] 施央申[1] 

机构地区：[1]南京大学地球科学系,北京石油勘探开发科学研究院

出　　处：《南京大学学报（自然科学版）》1995年第2期272-280,共9页Journal of Nanjing University（Natural Science）

摘　　要：黄骅拗陷天然气中存在强烈的幔源氦入侵，氦同位素比值３Ｈｅ／４Ｈｅ０．１２Ｒａ至３．６２Ｒａ，表明天然气中氦组分有１％至４５％来自幔源。３Ｈｅ／４Ｈｅ频率分布图呈双峰式特点，低值峰０．１２Ｒａ至１．１９Ｒａ，位于新生代中后期构造、岩浆活动不发育和远离断裂交汇带地区，其仍远高于壳源流体特征０．０２Ｒａ，表明拗陷区总体上存在较强的幔源氦混染。高值峰１．２８Ｒａ至２．８０Ｒａ，均位于长期活动断裂，特别是断裂交汇带和新生代火山活动区。幔源氦自断裂交汇带释放．沿ＮＥ—ＮＥＥ向伸展断裂带运移、聚集，并向四周扩散。早第三纪伸展活动与幔源岩浆作用期是幔源氦主要释放期；晚第三纪至第四纪ＮＷ向深断裂活动和深源岩浆作用对区内幔源氦聚集亦具重要贡献。Helium isotope ratios in Huanghua depression natural gas wells show a strong mantle signal. The 3He/4He ratios range from 0. 12 times the atmospheric ratio(0. 12 Ra) to 3. 62 Ra, indication that 1. 25% to 45% of the helium is mantli-derivde. The frequency of R/Ra presents two peaks. The samples of lower value peak(0. 12-1. 19 Ra) are located in the areas where fault and magmatism are undeveloped after middle Cenozoic and are far from the cross areas of faults; their 3He/4He ratios are much higher than that of crustal (0. 02 Ra), indicating this area has stronger mantle-derived helium discharge on the whole. The samples of higher value peak (1. 28-2. 80 Ra) are located on active faults of long period, especially, cross areas of these faults, and volcanic areas of Cenozoic period, showing that mantle- derived helium discharge from cross areas, migrate and accumulate along NE-NEE direction extinsive faults, and spread in all directions. Paleogene was the main discharge period of mantle -derived helium when extension and mantle-derived magmatism developed. In Neogene and Quaternary periods, the discharge of mantle-derived helium made its contribution to helium accumlation when NW direction deep fault and deep original rnagmatism developed.

关 键 词：同位素 氩含量 构造活动 天然气 幔源氦 

分 类 号：P618.130.2[天文地球—矿床学]