本文選題：礦床地質(zhì)　切入點(diǎn)：礦床地球化學(xué)　出處：《中國(guó)地質(zhì)大學(xué)(北京)》2015年碩士論文

【摘要】：廣西全州鈾礦田為華南鈾成礦區(qū)一處典型的碳硅泥巖型鈾礦田。本文在廣泛收集前人資料的基礎(chǔ)上,對(duì)該礦田中的典型鈾礦床進(jìn)行了詳細(xì)的礦床地質(zhì)和地球化學(xué)研究,重點(diǎn)論述了全州鈾礦田的成礦條件和形成過(guò)程,取得了一些有意義的成果和認(rèn)識(shí)。野外調(diào)研和鏡下觀察結(jié)果表明,全州鈾礦田主要賦礦地層為中泥盆統(tǒng)信都組近陸源碎屑巖和唐家灣組淺海相碳酸鹽巖以及上泥盆統(tǒng)榴江組淺海相碳酸鹽巖地層。礦體主要呈似層狀和透鏡狀沿F1和F3層間破碎帶分布,其產(chǎn)狀與地層和構(gòu)造產(chǎn)狀基本一致。在全州鈾礦田各鈾礦床中主要有泥質(zhì)粉砂巖和白云巖兩種類(lèi)型礦石,另有少量構(gòu)造泥型礦石。泥質(zhì)粉砂巖型礦石的礦石礦物主要是瀝青鈾礦、白鎢礦和少量晶質(zhì)鈾礦等,脈石礦物主要是石英、綠泥石、高嶺石和蒙脫石等;白云巖型礦石的礦石礦物主要為瀝青鈾礦和白鎢礦等,脈石礦物主要為白云石和方解石。鉆孔剖面和巖相學(xué)資料表明,全州鈾礦田內(nèi)的鈾礦床圍巖蝕變分布一般較窄,分帶不明顯。蝕變往往集中于斷裂帶附近,自礦床邊緣往中心部位明顯增強(qiáng)。與礦化密切相關(guān)的圍巖蝕變有赤鐵礦化、黃鐵礦化、方鉛礦化、碳酸鹽化、綠泥石化等。根據(jù)相互穿插關(guān)系、礦物組合和結(jié)構(gòu)構(gòu)造,可將全州鈾礦田鈾礦成礦過(guò)程分為沉積成巖期、熱液期和表生期三個(gè)成礦期,其中的熱液期又可以進(jìn)一步分為赤鐵礦—瀝青鈾礦、瀝青鈾礦—硫化物—方解石、方解石三個(gè)階段。從論文獲得的資料來(lái)看,全州鈾礦田中的鈾礦床是典型的沉積-低溫?zé)嵋函B加礦床。在沉積成巖期,加里東期含鈾花崗巖的風(fēng)化、剝蝕和沉積導(dǎo)致區(qū)內(nèi)中上泥盆統(tǒng)地層初步富鈾。在熱液期,大氣降水和地下水通過(guò)對(duì)富鈾地層的淋濾形成了含礦熱液,當(dāng)含礦熱液運(yùn)移到F1、F3層間破碎帶時(shí),由于Eh、溫度和壓力等的改變,鈾最終沉淀下來(lái)。
[Abstract]:The Quanzhou uranium ore field in Guangxi is a typical carbon-silicon mudstone type uranium ore field in southern China. Based on the extensive collection of previous data, this paper makes a detailed geological and geochemical study of the typical uranium deposit in this ore field. The metallogenic conditions and forming process of Quanzhou uranium ore field are emphatically discussed, and some meaningful results and understandings are obtained. The field investigation and microscopic observation show that, The main ore-bearing strata in Quanzhou uranium ore field are the proximal continental clastic rocks of the Xindu formation of the Middle Devonian, the shallow marine carbonate rocks of the Tangjiawan formation and the shallow marine carbonate rocks of the Upper Devonian Yujiang formation. The orebodies are mainly stratiform and lenticular along F1. And F3 interlaminar fracture zone distribution, Its occurrence is basically consistent with stratigraphic and tectonic occurrence. There are mainly argillaceous siltstone and dolomite ores in each uranium deposit in Quanzhou uranium ore field. In addition, there are a few structural muddy ores. The ore minerals of argillaceous siltstone type are mainly bituminous uranium, scheelite and a small amount of crystalline uranium, etc. The gangue minerals are mainly quartz, chlorite, kaolinite and montmorillonite. The ore minerals of dolomite type ore are mainly bituminous uranium ore and scheelite, while gangue minerals are mainly dolomite and calcite. The borehole profile and petrographic data show that the alteration distribution of surrounding rock of uranium deposit in Quanzhou uranium ore field is generally narrow. The zonation is not obvious. The alteration is usually concentrated near the fault zone and obviously strengthened from the margin to the center of the deposit. The wall rock alteration closely related to mineralization is hematitization, pyrite, galena mineralization, carbonization, etc. According to the intercalation relationship, mineral assemblage and structural structure, the uranium mineralization process in the Quanzhou uranium ore field can be divided into three metallogenic periods: sedimentary diagenetic stage, hydrothermal stage and epigenetic stage. The hydrothermal period can be further divided into three stages: hematite-asphaltene uranium ore, bituminous uranium ore-sulphide-calcite, calcite. The uranium deposit in Quanzhou uranium ore field is a typical deposition-low temperature hydrothermal superposition deposit. During the sedimentary diagenetic period, weathering, denudation and sedimentation of the Caledonian uraniferous granites resulted in the initial enrichment of uranium in the middle and upper Devonian strata in the area. The precipitation and groundwater formed ore-bearing hydrothermal solution by leaching the uranium-rich strata. When the ore-bearing hydrothermal fluid moved to the F _ 1 / F _ 3 interlayer fracture zone, uranium precipitated eventually due to the changes of Eh, temperature and pressure.
【學(xué)位授予單位】：中國(guó)地質(zhì)大學(xué)(北京)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：P619.14

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 羅超;徐爭(zhēng)啟;程發(fā)貴;張成江;倪師軍;唐純勇;梁軍;張長(zhǎng)俊;;廣西373鈾礦床微量元素地球化學(xué)特征及其成因探討[J];地質(zhì)學(xué)報(bào);2013年05期

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本文編號(hào)：1694635