东胜铀矿砂岩中方解石富集及铀矿成因.pdf

2016年3月,第22卷,第1期,053-059页
高校地质学报
March2016,Vol.22,No.1,pP.053-059
Ceological Journal of China Universities
DOT:10.16108issn1006-7493.2015029
东胜铀矿砂岩中方解石富集及铀矿成因
冯乔4,秦宇“,付锁堂,柳益群,周鼎武
山东科技大学地球科学与工程学院,青岛266510;2.中?石油青海油田分公司,敦煌7356202
3.大陆动力学国家重点实验室,西北大学质系,西安710069
4.海游国家实验室海洋矿产资源评价与探浏抆术功能实验室,肯岛266071
摘要:东胜铀矿区方解石富集特征、无机碳氧同位素以及邻近气藏包裹体捕获压力、有机碳同位素和He/He的相关研究表
明,东胜铀成矿与深层天然气存在密切关系。方解石的C值-196%e~-1.11%,80值-17.13%~-9,00%,δC值的变化范
围较宽,可能是地表水和深层天然气影响程度不同所致。鄂尔多斯盆地北部气藏储层包裹体捕获压力从深部向浅部和从盆
地西南向东北方向逐渐降低的变化趋势表明,天然气为铀的转化提供了充足的还原剂,为大型东胜铀矿形成提供了必要条
件。天然气中HeHe比值证明东胜直罗组铀矿秒岩中没有有意义的幔源流休贡献。这些证据表明东胜矿砂岩中的方解石
是地表水和深部天然气共同作用的结果,这暗示了东胜大型铀矿床是由低温混合成矿作用形成的。
关键词:方解石;碳氧同位素;He/He比值;东胜铀矿
中图分类号:PG619.14
文献标识码:A
文章编号:1006-7493(2016)01-0053-07
The Enrichment of Calcite and the Genesis of Uranium Deposits
in Dongsheng Uranium Sandstone
FENG Qiao QIN Yu, FU Suotang LIU Yiqun,, ZHOU Dingwu
1. College of Geological Science and Engineering, Shandong University of Seience and Technology. Qingdao 266510. China
2. Qinghai Oilfield Branch Petrochina, Dunhuang 736202, China
3. State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xian 710069 China
4. Laboratory for Marine Mineral Resourees, National Laboratory for Marine Science and Technology, Qingdao 266071, China
Abstract: Research on calcite in Dongsheng uranium area is carried out including the enrichment characteristics, inorganic carbon
and oxygen isotopes, neighboring gas reservoirs inclusions trapping pressure, organic carbon isotopes and He/He ratios. Ihe results
show that there is a close relationship between Dongsheng uranium mineralization and deep natural gas. The 6C values range
from -19 6 to-1.1 I% and the 6 O values range from.13% to-900% in calcite. The values of C vary widely, maybe due to
the influence of surface water and deep natural gas. The gas reservoirs inclusion trapping pressures decreased from the deep to the
superficial part and from southwest to northeast in northern Ordos Basin, indicating that natural gas has supplied sufficient reducer for
the conversion f uranium necessary for the formation of larg-scale uranium. The Herhe ratio in natural gas indicates that Dongsheng
Zhiluo uranium sandstone has no meaningful contribution from mantle fluids. The evidence shows that the calcite is a result of joint
actions of surface water and deep gas in Dongsheng uranium sandstone, suggesting that Dongsheng large-scale uranium deposit was
formed by the effect of cryogenically mixed mineralization
收稿日期:2015-02-03:修回日期:2015-08-06
基金项目:海外及港澳学者合作研究基金(41428201);国家重点基础研究发展计划“973”项目(2003CB214603)资助
作者简介:冯乔,男,1963年生,博十,教授,主要从事油气地质、盆地分析与地球化学研究;Fmai: fengqiao9990126.om
通讯作者:秦宇,男,1988年生,博上研究生,主要从事盆地分析研究;E-mail:43461996)yqg.com