本文關鍵詞： 鉛鋅礦 木桐溝 礦物成分 地球化學特征 礦床類型　出處：《長安大學》2015年碩士論文　論文類型：學位論文

【摘要】：木桐溝鉛鋅礦床,位于東秦嶺海西~印支褶皺帶北緣,鳳太礦田水柏溝~譚家莊復背斜西部南緣,是秦嶺地區(qū)典型的中型鉛鋅礦床。在大地構(gòu)造位置上處于秦嶺地槽系北緣鳳縣~鎮(zhèn)安小區(qū)冒地槽中段。本文通過對木桐溝鉛鋅礦的礦床地質(zhì)、薄片鑒定、主微量元素、穩(wěn)定同位素地球化學特征進行研究,取得以下認識:1.木桐溝鉛鋅礦主礦體由于受到褶皺構(gòu)造和地層層位的控制,Ⅰ號礦體呈現(xiàn)鞍部厚大,翼部薄的特征,Ⅱ號礦體呈單斜板狀或?qū)訝?其水平切面呈豆莢狀,賦礦于古道嶺組和星紅鋪組。2.對礦床地質(zhì)特征進行研究,礦體呈鞍狀、似層狀、透鏡狀產(chǎn)出;物質(zhì)組成:礦石礦物成分為閃鋅礦、方鉛礦、黃鐵礦等,脈石礦物為石英、白云石、方解石等;礦石具條紋狀、層紋狀、浸染狀、網(wǎng)脈狀及塊狀構(gòu)造;交代、草莓、環(huán)狀、骸晶、溶蝕、共邊等結(jié)構(gòu);礦床圍巖蝕變,主要限于礦化帶內(nèi),有硅化、鐵碳酸鹽化、黃鐵礦化等,硅化和鐵碳酸鹽化與成礦關系密切,為標準型的近礦圍巖蝕變等。3.對鉛同位素進行鉛構(gòu)造模式投圖,通過其投點圖分析可知,木桐溝的鉛主要來自于上地殼,并混入了少量的地幔物質(zhì)。稀土元素具有較低的稀土元素總量,稀土同時表現(xiàn)出輕稀土富集,∑LREE與∑HREE比值、不明顯的Ce負異常和弱的負銪異常證明其為還原環(huán)境。4.木桐溝鉛鋅礦床S同位素組成,δ34S值的變化范圍為于4.1‰~12.8‰之間,平均7.47‰,極差為8.7‰,反映了本區(qū)有深源硫或地幔硫特征,沒有生物有機硫的參與,同時硫化物中硫來源很可能為當時海水硫酸鹽中的還原硫和深部硫的混合物。5.綜合對比木桐溝鉛鋅礦床與MVT和SEDEX礦床的特征,認為其礦床類型為噴流—沉積型。
[Abstract]:The Mutonggou lead-zinc deposit is located in the northern margin of the Hercynian-Indosinian fold belt in the East Qinling Mountains, and in the western southern margin of the Shuibaigou-Tanjiazhuang anticline in the Fengtai Orefield. It is a typical middle-sized lead-zinc deposit in Qinling area. It is located in the middle section of Fengxian ~ Zhenan district in the northern margin of Qinling geosyncline system. The deposit geology, thin section identification and main trace elements of Mutonggou Pb-Zn deposit are studied in this paper. The stable isotopic geochemical characteristics have been studied and the following understandings have been obtained: 1.The main orebody of Mutonggou lead-zinc ore body is controlled by fold structure and stratigraphic position, and the No. 1 orebody is characterized by large saddle thickness and thin wing. The No. 2 orebody is monocline or layered, and its horizontal section is pod-like. The orebody is located in Gudaoling formation and Xinghongpu formation. 2. The geological characteristics of the deposit are studied. The orebody is saddle-shaped, bedded and lenticular. Material composition: mineral composition of ore is sphalerite, galena, pyrite, etc., gangue mineral is quartz, dolomite, calcite, etc.; ore is striped, laminated, disseminated, reticulate and massive; metasomatism, strawberry, annular, etc. The alteration of the surrounding rock of the deposit is mainly confined to the mineralized zone, such as silicification, iron carbonate, pyrite, etc., and the silicification and iron carbonization are closely related to the mineralization. For the standard type near ore wall rock alteration, etc. 3. The lead isotopic pattern of lead structure is cast. Through the analysis of the drop point diagram, it can be seen that the lead of Mutong gully mainly comes from the upper crust. And mixed with a small amount of mantle material, the rare earth elements have a relatively low amount of rare earth elements, and the rare earth elements are enriched with light rare earth elements, and the ratios of 鈭，

本文編號：1551439