本文選題：巖石成因 + U-Pb年齡　； 參考：《高校地質(zhì)學(xué)報(bào)》2017年04期

【摘要】：安徽宣城茶亭Cu-Au礦床是長江中下游成礦帶內(nèi)新發(fā)現(xiàn)的一個(gè)斑巖型礦床。文章對該礦床賦礦石英閃長玢巖進(jìn)行了鋯石LA-ICP-MS U-Pb同位素年齡及巖石主量與微量元素、Sr-Nd同位素和鋯石Lu-Hf同位素分析,旨在探討其巖漿起源和巖石成因。鋯石U-Pb同位素年齡測定結(jié)果顯示,賦礦石英閃長玢巖形成年齡為137.8±1.3 Ma(MSWD=0.72),為早白堊世巖漿活動(dòng)的產(chǎn)物。巖石主量元素顯示其具富堿富鈉特征,為亞堿性準(zhǔn)鋁質(zhì)高鉀鈣堿性系列巖石。巖石微量元素顯示其富集大離子親石元素K、Rb、Sr、Ba和輕稀土元素,弱富集Zr和Hf,虧損高場強(qiáng)元素Nb、Ta、Ti等,稀土元素配分型式表現(xiàn)為無明顯Eu異常。巖石(~(87)Sr/~(86)Sr)_i值介于0.706403~0.707903之間,ε_(Nd)(t)值介于-7.4~-13.3之間(t=137.8 Ma)。鋯石ε_(Hf)(t)值為-4.25~-11.75(t=137.8 Ma)。主量元素、微量元素、Sr-Nd同位素和鋯石Hf同位素地球化學(xué)特征均指示,賦礦石英閃長玢巖可能是富集巖石圈地幔與揚(yáng)子下地殼物質(zhì)部分熔融形成的巖漿混合后侵位的產(chǎn)物。對比長江中下游成礦帶斷隆區(qū)和斷凹區(qū)侵入巖發(fā)現(xiàn),宣城茶亭礦床賦礦石英閃長玢巖與長江中下游成礦帶斷凹區(qū)(寧蕪、廬樅礦集區(qū)等)侵入巖,無論是巖石主量與微量元素地球化學(xué)特征還是同位素地球化學(xué)特征都存在一定差異,而與斷隆區(qū)(銅陵礦集區(qū))賦礦巖漿巖表現(xiàn)出一致性,暗示宣城茶亭礦床賦礦石英閃長玢巖與長江中下游成礦帶斷隆區(qū)巖漿巖有著基本一致的成巖物質(zhì)來源和巖石成因機(jī)制,是富集巖石圈地幔熔融巖漿及其引起的下地殼物質(zhì)部分熔融巖漿發(fā)生巖漿混合作用并伴隨著一定程度的分離結(jié)晶作用進(jìn)而淺成侵位形成。
[Abstract]:The Cu-Au deposit in Xuancheng, Anhui Province is a porphyry deposit found in the middle and lower reaches of the Yangtze River.In this paper, zircon LA-ICP-MS U-Pb isotopic age, major rock mass and trace element Sr ND isotopes and zircon Lu-Hf isotopes are analyzed for the diorite porphyrite bearing ore in the deposit. The purpose of this paper is to discuss the magmatic origin and petrogenesis of the porphyrite.The U-Pb isotopic dating of zircon shows that the age of formation of diorite porphyrite is 137.8 鹵1.3MaMS-WDX 0.72, which is the product of early Cretaceous magmatism.The main elements of the rocks show that they are rich in alkali and sodium, and belong to the subalkaline pseudo-aluminous high potassium calc-alkaline series rocks.The trace elements in the rocks show that they are rich in the large ion lithophile element K ~ (2 +) Rb ~ (2 +) Sr ~ (2 +) Ba and light rare earth elements, and are weakly enriched in Zr and HF, and depleted in the high field strength element Nb ~ (10) Ta-Ti, etc. The REE partitioning patterns show no obvious EU anomalies.The value of S / R / 86 / S / S / S / I is between 0.706403 and 0.707903, and the value of 蔚 _ S / N _ (D) is between -7.4 ~ 13.3 ~ 137.8 Ma ~ (-1).The value of zircon 蔚 -Hfnn is -4.25 ~ 11.75 ~ 137.8 Ma ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1).The geochemical characteristics of major elements, trace element Sr ND isotopes and zircon HF isotopes indicate that the ore-bearing diorite porphyrite may be the product of magmatic emplacement resulting from the partial melting of the enriched lithospheric mantle and the lower Yangtze crust material.In contrast to the intrusive rocks in the middle and lower reaches of the Yangtze River in the fault-uplift and fault-sag areas, it is found that the Xuancheng Tea Ting deposit is filled with diorite porphyrite and the fault-sag areas of the middle and lower reaches of the Yangtze River (Ningwu, Luzong ore concentration, etc.) intrusive rocks.There are some differences in the geochemical characteristics of major and trace elements or isotopic geochemistry of rocks, but are consistent with the ore-bearing magmatic rocks in the faulted uplift area (Tongling ore concentration area).It is suggested that the ore-bearing diorite porphyrite is basically consistent with the magmatic rocks in the fault-uplift area of the middle and lower reaches of the Yangtze River.It is the magmatic mixing of enriched lithospheric mantle molten magma and the partial melting magma of the lower crust, which is accompanied by a certain degree of separation and crystallization and then the formation of superficial emplacement.
【作者單位】： 合肥工業(yè)大學(xué)資源與環(huán)境工程學(xué)院;安徽省地質(zhì)礦產(chǎn)勘查局322地質(zhì)隊(duì);
【基金】：國家自然科學(xué)基金(41472066) 安徽省國土資源科技項(xiàng)目(2014K3)資助
【分類號】：P588.1;P618.2

【相似文獻(xiàn)】

相關(guān)期刊論文 前10條

1 汪晶;吳明安;李小東;張舒;趙文廣;魏國輝;;廬樅盆地早白堊世閃長玢巖鋯石U-Pb年齡、地球化學(xué)特征及其成礦指示意義[J];地質(zhì)學(xué)報(bào);2014年04期

2 李鄂榮;朱德魁;;三門峽閃長玢巖的顯微鏡鑒定[J];水文地質(zhì)工程地質(zhì);1957年12期

3 周國慶;姜堯發(fā);仝炳炎;;徐州泉山閃長玢巖巖體地質(zhì)與地球化學(xué)特征[J];地質(zhì)學(xué)刊;2011年03期

4 奧琮;孫豐月;李碧樂;李世金;王冠;;青海夏日哈木礦區(qū)中泥盆世閃長玢巖鋯石U-Pb年代學(xué)、地球化學(xué)及其地質(zhì)意義[J];西北地質(zhì);2014年01期

5 范裕;周濤發(fā);袁峰;張樂駿;錢兵;馬良;David RC;;寧蕪盆地閃長玢巖的形成時(shí)代及對成礦的指示意義[J];巖石學(xué)報(bào);2010年09期

6 高立文;;廬江黃屯閃長玢巖巖床特征初議[J];安徽地質(zhì);1993年02期

7 石楠;周新;何建娟;;西藏納屋錯(cuò)地區(qū)閃長玢巖鋯石U-Pb年代學(xué)及地質(zhì)意義[J];礦物學(xué)報(bào);2013年S2期

8 丁毅;;寧蕪地區(qū)輝石閃長玢巖形成新解[J];江蘇地質(zhì);1991年04期

9 林清茶;夏斌;張玉泉;;云南中甸地區(qū)雪雞坪同碰撞石英閃長玢巖鋯石SHRIMP U-Pb定年及其意義[J];地質(zhì)通報(bào);2006年Z1期

10 彭玉旋;徐國;夏冬;謝燕;;淶源木吉村礦區(qū)賦礦巖體——閃長玢巖巖相學(xué)研究[J];內(nèi)蒙古科技與經(jīng)濟(jì);2012年10期

相關(guān)會(huì)議論文 前4條

1 劉玉山;程萊仙;繆婉萍;;閃長玢巖在高溫高壓下與氯化物溶液作用析出鐵的實(shí)驗(yàn)研究(1980)[A];中國地質(zhì)科學(xué)院礦床地質(zhì)研究所文集（18）[C];1986年

2 汪洋;仝立華;;環(huán)斑結(jié)構(gòu)成因及其對相關(guān)巖石成因的啟示[A];中國礦物巖石地球化學(xué)學(xué)會(huì)第13屆學(xué)術(shù)年會(huì)論文集[C];2011年

3 張繼慶;蒲心純;官舉銘;王熙林;陸元法;羅安屏;黃惠瓊;;湘西、黔東上震旦統(tǒng)巖石成因類型及沉積相[A];中國地質(zhì)科學(xué)院文集（1981）[C];1983年

4 呂勇軍;劉樹文;李秋根;劉超輝;;五臺山太古宙變質(zhì)基性巖的地球化學(xué)及巖石成因[A];2006年全國巖石學(xué)與地球動(dòng)力學(xué)研討會(huì)論文摘要集[C];2006年

相關(guān)碩士學(xué)位論文 前2條

1 崔蒙;內(nèi)蒙古雙尖子山銀多金屬礦成礦巖體地球化學(xué)特征與成巖作用[D];中國地質(zhì)大學(xué)(北京);2015年

2 孟慶玲;冀西石湖金礦的石英閃長玢巖年代學(xué)、地球化學(xué)研究及地質(zhì)意義[D];中國地質(zhì)大學(xué)(北京);2012年

，

本文編號：1752261