The Occurrence of Anthraxolite in Longtoushan Reef Limestone Region of Dachang Ore Field and Its Relatioa to Poly metallic Mineralization
-
摘要: 碳沥青在大厂矿田龙头山礁灰岩区分布广泛，其主要产出形式为充填于碳灰岩岩溶孔洞，原生扎除及方解石裂隙豚中，在锡石一硫化物矿体内及花岗班岩与礁灰岩的接触面上也见碳沥青分布。对碳沥青及龙头山地区生、储、盖条件的分析表明，生物礁内曾有过油气的运移和储集过程。稳定同位素与流体包裹体成分特征显示了有机质参与金属成矿的明显迹象。推测泥盆纪海底喷流一沉积成矿时期是油气活动的重要时期之一，油气田最终的破坏与燕山晚期花岗岩浆侵入有关。有机质参与金属成矿的作用机制主要表现在：富含有机质的油田卤水促使地层中成矿元素活化、迁移和富集；形成热水岩溶──礁灰岩中的主要成矿空间；提供丰富的硫源；制约成矿环境的物理化学条件等。另一方面，泥企纪海底热水活动和燕山晚期岩浆侵入为油气演化和油田卤水运移提供了动力，尤其是后者加速了油田的变质，导致轻质组分挥发，留下了大量的碳沥青。Abstract: Antlsraxolite is very common in Longtoushan reef limestone region. The main mode of occurrence of anthraxolite is in karst cavities,primary holes of reef limestone and in calcite veins. Some anthraxolite is discovered in cassiterite-sulphide ore bodies and in contact plane between granite- parphgy and reef limestone. Studies about anthraxolite and conditions of source- reservior-caprock association indicate that there was oil-gas migration and reservior in the reef in past geological history .The composition feature of stable isotopic and fluid inclusion shows a close relation between organic matter and polymetallic mineralization. One of the main period of petroleum evolution had a bearing on the seafloor exhalative sedimentary mineralization in Devo- nion. The final damage of oil-gas field related to magmatic activity in late Yenchan period. Organic matter played an impartant pole in polymetallic mineralization:Thermal brine containing organic matter promoted some ore-forming elements to be activated and migrate from strata,and at the same time to form hot-water karst in reef limestone which is the main space for mineralization and provide sulphur to controll to the physicochemical condition of ore-forming environment. On the other hand, submarine hot-water activity in Devonion and intrusion of magma in Yenchan period provided power for oil- gas evolution and migration of brine containing organic matter. Eventually the heat of magma accelerated the degradation and metamor-phism of organic matter. Light component volatilized and much anthraxolite remained.
-
Key words:
- anthraxolite /
- occurrence /
- relation to mineralization /
- reef limestone /
- Dachang
-
[1] 1 涂光炽.中国层控矿床地球化学(第三卷)[M].北京:科学出版社，1988
2 陈统川.大厂锡矿地质[M].北京:地质出版社，1993
3 叶绪孙.广西大厂超大型锡矿床成矿条件[M].北京:冶金地质出版社，1996
4 Fu M,et al. An oxygen, hydrogen,sulfur and carbon isotope study of Dachang Tin-field,China[J]. Econ. Geol.,1991, 86
5 张德会.矿物包裹体液相成分特征及其矿床成因意义[J].地球科学,1992,6
6 B. A.克拉尤什金.大洋裂谷带的热液油气[J].国外地质科技，1993,6
7 赓宗廷.古海洋中的热水喷口一广西大厂例析[J].同济大学学报，1995,5
8 卢家烂.沉积改造矿床形成中的若干有机地球化学问题[J].沉积学报，1991，增刊
9 Goldhber M B,et al. Rlation among hydrocarbon reserviors Bepi-genetic sulfidization and rock magnetization; Examples from the.
10 South Texas coastal plain[J].Geophysics,1991,56[J]10 庄汉平等.与有机质有成因联系的金属矿床[J].地质地球化学，1996,4[J]11 -
点击查看大图
计量
- 文章访问数: 505
- HTML全文浏览量: 36
- PDF下载量: 475
- 被引次数: 0
下载:
