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在犹他州圣胡安郡的蒙特朱玛谷(Montezuma Canyon),赋存于莫里森建造(Morrison Formation)的萨尔特·瓦什(Salt Wash)组中的铀-钒矿床具有带状分布,这种带状分布是由于扩散作用引起金属元素迁移的结果。同心圆带包括褐色非矿化核心、灰绿色矿化层和灰色非矿化外带。褐色带是铁染的多孔砂岩,常含大量的含碳物质。弯曲的矿化层由浸染砂岩的已氧化铀-钒矿物组成,它紧紧地包围着褐色带。灰色带内的岩石是由方解石紧密胶结的浅灰色砂岩,在这个带中常出现褐铁矿斑点。矿床最可能是在晚白垩纪或早三迭纪形成的。在那个时候,含矿砂岩埋藏在深处,并饱含封存水。在褐色带中有机物质的富集表明,在该带内曾经充满着含可溶性有机化合物(例如从有机物质分解出来的醇和醛)的还原溶液。另一方面,在灰色带中可能充满着含铀和钒的氧化溶液。在两种溶液相互接触的地方发生氧化还原作用,从而使低价铀和钒的矿物沉淀下来。矿层呈椭球形状,流动溶液没有任何出入口,这一切都说明,由于扩散作用,溶解的金属经过灰色带而沉淀在还原带的周围。现代风化作用和氧化作用使原来的低价矿物变成高价矿物,而矿石中的金属并没有显著的淋失。
In the Montezuma Canyon, San Juan County, Utah, the uranium-vanadium deposits in the Salt Wash Formation of the Morrison Formation have a banded distribution, The shape-like distribution is the result of metal element migration due to diffusion. Concentric bands include brown non-mineralized core, gray-green mineralized layer and gray non-mineralized belt. Brown belt is iron dye porous sandstone, often containing large amounts of carbonaceous material. The curved mineralized layer consists of uranium oxide-vanadium minerals that have been impregnated with sandstone, tightly surrounding the brown belt. The rocks in the gray band are light gray sandstone that is cemented by calcite, a spot of limonite often found in this zone. The deposit is most likely formed in the late Cretaceous or Early Triassic. At that time, ore-bearing sandstones were buried deep and filled with sea water. The enrichment of the organic material in the brown belt indicates that the belt was once filled with a reducing solution containing soluble organic compounds, such as alcohols and aldehydes that are decomposed from organic matter. On the other hand, gray bands may be filled with an oxidizing solution containing uranium and vanadium. Redox occurs where the two solutions come into contact with each other, thereby precipitating low-grade uranium and vanadium minerals. The ore layer is ellipsoidal and there is no access to the flowing solution. All this shows that due to the diffusion, the dissolved metal precipitates around the reduction zone through the gray zone. Modern weathering and oxidation of the original low-cost minerals into high-value minerals, and minerals in the ore and no significant leaching.