川北广元田坝子剖面含铀沥青脉的发现及其地质意义

通过野外地质调查,在四川盆地西北部广元市青川县田坝子剖面发现了多处具铀异常(≈70×10-6)的含铀沥青脉.对含铀沥青脉开展了矿物学、元素地球化学、光谱学研究,并与研究区典型砂岩型铀矿床(303矿床)中的"有机质"开展了对比研究.研究表明,含铀沥青脉中含有大量的微粒状矿物,包括微米级的石英、重晶石、黄铜矿、闪锌矿、方铅...

Discovery and geological significance of the U-bearing bitumen vein from the Tianbazi section in Guangyuan,Northern Sichuan

A U-bearing bitumen vein with uranium anomalies(~70×10^-6,several locations)was identified in Qingchuan County,Guangyuan City,northern Sichuan Basin.The mineralogy,element geochemistry,and spectroscopy analyses were carried out for this U-bearing bitumen vein,with comparison to the“organic matters”in the nearby typical sandstone type uranium deposit(303 deposit).The U-bearing bitumen vein contains a large number of micro-grained minerals,including micro-sized quartz,barite,chalcopyrite,sphalerite,galena and strawberry-like pyrite with micro—nano structures.The bitumen vein is highly enriched in Mo,Re,Cd,U,and Ba,with slightly elevated Sc,V,Ni,Cu,Zn,Rb,Tl contents.Similar uranium-and bitumen-bearing veins have also been found in the 303 sandstone-type uranium deposit,with similar mineralogy(barite—pyrite—sphalerite and other minerals)and trace element concentrations.It is suggested that the uranium mineralization in northern Sichuan may be genetically related to the cracking and destruction of paleo-oil reservoirs.In the tectonic active area in the Sichuan Basin,it might be potential to find uranium deposits related to oil—gas activities.The U,Mo,and Re contents in the bitumen veins are all significantly enriched and could be comprehensively utilized after the bitumen was burned,it is therefore recommended to pay attention to these bitumen veins for comprehensive utilization of the aforementioned associated elements in future in northern Sichuan.