本文選題：晚中生代 + 紅-黑巖系耦合��； 參考：《中國(guó)地質(zhì)》2017年02期

【摘要】：為研究中國(guó)北方陸相盆地紅層-黑色巖系對(duì)砂巖型鈾成礦的制約,文章研究了國(guó)內(nèi)外紅-黑巖系與砂巖型鈾礦賦存巖層的時(shí)空關(guān)系,篩選了10萬(wàn)余m巖心鉆探資料,選擇準(zhǔn)噶爾、鄂爾多斯和松遼盆地這3個(gè)典型產(chǎn)鈾盆地,通過(guò)編制盆地鉆孔柱狀圖、典型地區(qū)連井剖面圖及關(guān)鍵巖層的地球化學(xué)測(cè)試等方法,對(duì)紅-黑巖系和砂巖型鈾礦的賦存巖層進(jìn)行了垂向、橫向上綜合分析與對(duì)比。研究發(fā)現(xiàn):北方陸相盆地自西向東鈾礦賦存地層的時(shí)代由中侏羅世過(guò)渡到晚白堊世;晚中生代至少存在6次大規(guī)模的富氧紅層沉積事件:Ⅰ中侏羅世—晚侏羅世早期(BathonianOxfordian),Ⅱ早白堊世早中期(Berriasian-Barremian),Ⅲ早白堊世中期(Barremian),Ⅳ晚白堊世早期(Cenomanian),Ⅴ晚白堊世中期(Coniacian)和Ⅵ晚白堊世晚期(Campanian)。其中第Ⅰ、Ⅴ和Ⅵ期紅層之下沉積了時(shí)代相近的黑色層,與之構(gòu)成"紅-黑巖系"的沉積結(jié)構(gòu),是北方砂巖型鈾成礦的3個(gè)重要層位。典型盆地內(nèi)地球化學(xué)表明,紅層與黑色層的B、Sr和Cu元素含量及Fe~(2+)/Fe~(3+)、B/Ga、Sr/Cu和FeO/MnO比值具有明顯的差異,結(jié)合黑色巖層中草莓狀黃鐵礦、碳屑、油斑和紅層中碳酸鹽巖的發(fā)育,認(rèn)為紅層為相對(duì)較強(qiáng)氧化環(huán)境,黑色層為相對(duì)較還原環(huán)境。連井剖面資料顯示紅層、黑色層與砂巖型鈾礦空間關(guān)系密切,鈾礦多產(chǎn)于紅層與黑色層之間過(guò)渡帶上,呈板狀礦體賦存于灰色、綠灰色砂巖和細(xì)砂巖中。一般紅層與黑色層垂向距離超過(guò)500 m不利于成礦。晚中生代陸相盆地內(nèi)耦合產(chǎn)出的黑色巖系和紅色巖系是古沉積環(huán)境由還原向氧化轉(zhuǎn)變形成的垂向分帶,前者為鈾礦物質(zhì)沉淀提供了"障",后者為表生流體溶解鈾礦提供了"場(chǎng)"。文章初步提出了紅-黑巖系垂向環(huán)境變化制約著北方陸相盆地砂巖型鈾大規(guī)模成礦作用的新認(rèn)識(shí)。這些認(rèn)識(shí)不僅對(duì)砂巖型鈾礦成礦環(huán)境、成礦規(guī)律及成礦模式研究具有重要意義,更對(duì)目前正在開(kāi)展的砂巖型鈾礦勘查工作具有實(shí)踐指導(dǎo)意義。
[Abstract]:In order to study the constraints of red bed and black rock series on sandstone-type uranium mineralization in continental basins of northern China, this paper studies the space-time relationship between red-black rock series and sandstone type uranium deposits at home and abroad, and selects more than 100000 m core drilling data. The three typical uranium-producing basins, Junggar, Ordos and Songliao basins, are selected. By compiling the borehole bar map of the basin, the section map of the connected wells in the typical area and the geochemical test of the key strata, etc. The vertical, horizontal and comprehensive analysis and comparison of the occurrence of red-black rock series and sandstone-type uranium deposits are carried out. It is found that the age of uranium deposits from west to east in the northern continental basin has changed from the Middle Jurassic to the late Cretaceous. There were at least six large-scale oxygen-rich red bed sedimentary events in the late Mesozoic: 鈪，

本文編號(hào)：1878928