摘要
国内外沉积盆地中铀的富集不同程度地伴随烃源岩的形成。铀作为一种兼具催化、氧化和放射性的特殊元素,其对有机矿产的形成及演化可能具有重要的促进作用,通过调查并统计国内外烃源岩中铀含量,在分析铀与各类矿物、有机质及微生物等相互作用的基础上,讨论了铀在海相烃源岩中的富集条件及主控因素,提出古大气和古海洋的氧化程度是烃源岩中铀富集的主要控制因素,陆地含氧风化和海底热液可能是海相沉积铀的2个主要来源,含铁矿物组成、有机质、磷酸盐矿物、黏土矿物及一些微生物等均可导致铀价态转化,并作为载体,通过吸附或络合作用使铀在沉积物中富集。因此,铀富集可能是烃源岩形成的一个伴随结果。
The research of petroleum exploration demonstrates that source rocks, developed in petroleum-bearing sedimentary basins worldwide, are accompanied by uranium to different degrees. As a special element with catalytic, oxidative and radioactive features, uranium may play important roles in the source rock formation and hydro- carbon generation. In this paper, we systematically discussed the formation conditions and main controlling factors of uranium in marine source rocks based on the comprehensive analysis of uranium contents in the worldwide source rocks and the interactions of uranium with minerals, Organic materials and microbes. The results indicated that oxidative degrees of ancient atmosphere and palaeo-ocean were governing factors of uranium enrichment in source rocks. Oxidative weathering and hydrothermal solution might be the two main sources of marine sedimentary uranium. In addition, iron-bearing minerals, phosphate minerals, clay minerals, organic materials, and microbes were of great significance in promoting the transformation of the uranium valence states. They could also act as carriers to absorb or combine uranium, resulting in the enrichment of uranium in sediments. Therefore, the enrichment of uranium might be an inevitable result of source rocks formation.
出处
《地球科学进展》
CAS
CSCD
北大核心
2017年第2期199-208,共10页
Advances in Earth Science
基金
国家自然科学基金重点项目"中国元古代海相烃源岩形成的生物
海洋和地质因素及耦合关系研究"(编号:41530317)
国家自然科学基金青年科学基金项目"铀的放射性作用对有机质成熟和生烃的影响"(编号:41602144)资助~~
关键词
铀
烃源岩
铁
有机质
古海洋
Uranium
Source rocks
Iron
Organic materials
Palaeo-ocean.
