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法基利(Fakili)矿床位于土耳其西部埃热(Egé)地区北部。矿床周围主要岩石为门德雷斯地块(Massif de Menderes)的变质岩系和晚第三纪沉积物。变质岩系一般含有球状片麻岩等,并构成晚第三纪沉积盆地的基底。晚第三纪沉积物可分为三部:底部为碎屑岩系,上部为泥灰岩系,顶部为湖相石灰岩。碎屑岩系由粘土、粉砂岩、砂石、卵石和砾岩组成。下部具有河相的显著特征,并有交错层理。在岩系上部,从下部河相沉积物起,为具有侧向连续性的水平层位的湖相沉积。泥灰岩层由凝灰层上的粘土、粉砂岩、砂岩和泥灰岩互层组成。此岩系不均匀,且不规则。可见到有许多岩相变化。但一般说来同一层位有两个明显不同的岩相。第一岩相代表岩系的总特征,并含有泥灰岩。第二岩相是法基利岩相。它与第一岩相不同,其特征如下:颜色繁杂,泥灰岩、次生石膏、沉积黄铁矿缺失,放射性一般增大。法基利铀矿床位于此岩相内。湖相石灰岩为晚第三纪湖泊的最年轻的沉积物。法基利铀矿床的形成分成两个期:铀的同生沉淀和后成富集。在泥灰岩系沉积初期,湖水富含呈溶解状态的铀。晚第三纪碎屑岩系中的硫酸盐含量在近法基利岩相底部变富。在法基利岩相接触带上部,硫酸盐含量达到最大值,并向顶部减少。硫酸盐这种富集是由于湖中这个部位的蒸发作用。使硫酸盐沉淀富集的蒸发作用也同样使在湖的这部位的大量呈溶解状态的铀富集。湖水显示出由酸性变为中性,一方面因为硫酸盐减少,另一方面是因为 CaCO_3含量增加。铀不能在中性水中呈溶解状态存留,便在硬石膏之后大量沉淀。这就是铀在湖中的同生沉淀。在晚第三纪晚期,湖水退走,晚第三纪沉积物遭受蚀变,并受气候影响而剥蚀。当渗流水渗透时,铀第二次溶解,并呈硫酸盐组分沉淀在法基利岩相底部接触带上部的非均质部位中。由于这种后成富集,在法基利铀矿床中便形成了一些扁豆体。
The Fakili deposit is located in the northern part of the Egé region of western Turkey. The main rocks around the deposit are metamorphic rocks and Late Tertiary sediments of the Massif de Menderes. Metamorphic rocks generally contain globular gneiss, etc., and constitute the basement of the late Tertiary sedimentary basin. Late Tertiary sediments can be divided into three: the bottom of the clastic rocks, the upper part of the marl, the top of lacustrine limestone. Clastic rocks are made of clay, siltstone, gravel, pebbles and conglomerates. The lower part has the distinctive characteristics of the river facies, with staggered bedding. In the upper part of the rock series, from the lower river sediments, lacustrine deposits are deposited in horizontal horizons with lateral continuity. The marl layer is composed of interlayers of clay, siltstone, sandstone and marl on the tuff layer. The rock is uneven and irregular. There are many lithofacies changes seen. But in general there are two distinctly different lithofacies in the same horizon. The first facies represent the general characteristics of the rock series and contain marl. The second facies is Faquili facies. It is different from the first lithofacies and is characterized by the following: complex color, marl, secondary gypsum, missing sedimentary pyrite and generally increased radioactivity. The Faquili uranium deposit is located in this facies. Limestone limestone is the youngest sediment of the late Tertiary lake. The formation of the Faquili uranium deposit is divided into two periods: the simultaneous deposition of uranium and the enrichment. Early in the marl sedimentation, the lake was rich in dissolved uranium. The sulfate content in the Late Tertiary clastic rocks enriched near the basement of the Kiri lithofacies. At the upper part of the Faquili contact zone, sulfate content reached its maximum and decreased toward the top. This enrichment of sulphate is due to the evaporation of this part of the lake. Evaporation that enriches sulphate precipitation also likewise enriches a large amount of dissolved uranium in this part of the lake. The lake shows a shift from acidic to neutral, on the one hand because of the reduction of sulphate and on the other hand because of an increase in CaCO 3 content. Uranium can not be dissolved in neutral water to survive, then a lot of precipitation in the anhydrite. This is the simultaneous deposition of uranium in the lake. In late late Tertiary, the lake receded, the sediments of the Late Tertiary underwent alteration and were denuded by the weather. When seepage water infiltrates, the uranium dissolves for the second time and precipitates as a sulfate component in the non-homogeneous part of the upper part of the contact zone at the bottom of Fajiri lithofacies. Due to this post-enrichment, some lentils were formed in the Faquili uranium deposit.