本文關(guān)鍵詞：吉林百草溝金礦閃長(zhǎng)玢巖鋯石U_Pb年代學(xué)、地球化學(xué)及其地質(zhì)意義　出處：《礦床地質(zhì)》2016年05期 　論文類型：期刊論文

  更多相關(guān)文章： 地球化學(xué) 鋯石U_Pb年齡 百草溝金礦 閃長(zhǎng)玢巖 活動(dòng)大陸邊緣

【摘要】：文章對(duì)延邊地區(qū)百草溝金礦床與成礦有關(guān)的閃長(zhǎng)玢巖脈進(jìn)行了鋯石LA_ICP_MS U_Pb年代學(xué)和地球化學(xué)研究。閃長(zhǎng)玢巖中的鋯石U_Pb定年結(jié)果顯示,閃長(zhǎng)玢巖形成時(shí)代為早白堊世((128±3)Ma,MSWD=0.29)。巖石元素地球化學(xué)研究表明巖石屬于高鉀鈣堿性系列,明顯富集大離子親石元素(如K、Ba、Rb)、LREE和強(qiáng)不相容元素(如Th、U),相對(duì)虧損高場(chǎng)強(qiáng)元素(如Ta、Nb、Ti、P),Mg#值為42~54,其地球化學(xué)特征與活動(dòng)大陸邊緣背景下形成的火成巖相似。巖石中w(Cr)為20.0×10-6~33.4×10-6,Nb/Ta比值為9.7~16.5,La/Nb比值為2.54~3.67,Th/La比值為0.19~0.43,Rb/Sr值比為0.10~0.33,閃長(zhǎng)玢巖巖漿是由地殼物質(zhì)和地幔物質(zhì)混合形成的。結(jié)合野外地質(zhì)特征及年代學(xué),認(rèn)為與礦床近同時(shí)形成的閃長(zhǎng)玢巖,其形成的構(gòu)造背景應(yīng)為古太平洋板塊斜向亞洲大陸俯沖的活動(dòng)大陸邊緣。
[Abstract]:Zircon LA_ICP_MS of diorite porphyrite veins related to mineralization of Baicaogou gold deposit in Yanbian area has been carried out in this paper. U-Pb geochronology and geochemistry. Zircon dating of zircon from diorite porphyrite shows. The diorite porphyrite was formed at an early Cretaceous age of 128 鹵3 MaMSWDU 0.290.The geochemistry of the rocks indicates that the rocks belong to the calc-alkaline series of high potassium. The large ion lithophile elements (such as K _ (+) Ba _ (B) Rb ~ (+)) LREE and strongly incompatible elements (such as Thu U ~ (2 +), relatively depleted high field strength elements (such as Tahe NbTiPe) are obviously enriched. The Mg# value is 42 #number0#, and its geochemical characteristics are similar to those of igneous rocks formed in the active continental margin. The ratio of Nb/Ta to La / NB is 9.7and 16.5nb is 2.54 / 3.67U / L / La ratio is 0.19nb / 0.43. The Rb/Sr ratio is 0.10 ~ 0.33 and the diorite porphyrite magma is formed from the mixture of crustal and mantle materials. Combined with the field geological characteristics and geochronology, it is considered that the diorite porphyrite formed near the same time as the deposit. The tectonic setting is the active continental margin in which the paleo-Pacific plate dips to the Asian continent.
【作者單位】： 中國(guó)地質(zhì)科學(xué)院礦產(chǎn)資源研究所國(guó)土資源部成礦作用與資源評(píng)價(jià)重點(diǎn)實(shí)驗(yàn)室;北京大學(xué)地球與空間科學(xué)學(xué)院;吉林大學(xué)地球科學(xué)學(xué)院;
【基金】：吉黑東部區(qū)域成礦規(guī)律綜合研究項(xiàng)目(編號(hào):1212011085485) 中央高校基本科研業(yè)務(wù)費(fèi)專項(xiàng)資金(編號(hào):310827161011)聯(lián)合資助
【分類號(hào)】：P597.3;P618.51
【正文快照】： combination with their Mg#values(42~54),it is suggested that the features of the rocks are similar to the charac-teristics of active continental margin magma.Based on the data Cr=(20.0~33.4)×10-6,Nb/Ta=9.7~16.5,La/Nb=2.54~3.67,Th/La=0.19~0.43,and Rb/Sr=，

本文編號(hào)：1433941