【摘要】：我國(guó)東北地區(qū)分布有大量中生代(侏羅紀(jì)至白堊紀(jì))火山巖。選取大興安嶺西緣瑪尼吐組粗安巖-粗面英安巖-流紋巖為研究對(duì)象,研究結(jié)果顯示它們?yōu)楦哜涒}堿性的火山巖,主量、微量元素含量變化較大,SiO_2含量為56.71%~71.85%,Na_2O+K_2O含量為5.92%~10.18%,Na_2O/K_2O比值較高,為0.78~1.33,Mg~#為30.6~56.4�，斈嵬陆M火山巖的稀土元素配分圖和微量元素蛛網(wǎng)圖右傾明顯,可見(jiàn)明顯的Nb、Ta、Ti、Sr和Eu負(fù)異常(Nb~*=0.17~0.71,Sr~*=0.24~1.15,Eu~*=0.49~0.77)。稀土總量較高,為200×10~(-6)~949×10~(-6)。結(jié)果分析可知,瑪尼吐組火山巖源巖與霍林河火山巖源巖相似,均為混合了少量先存古老地殼的新生基性下地殼。新生基性下地殼部分熔融形成安山質(zhì)巖漿,并經(jīng)角閃石+斜長(zhǎng)石+鉀長(zhǎng)石+磷灰石+鈦磁鐵礦等的分離結(jié)晶形成了瑪尼吐組粗安巖-粗面英安巖-流紋巖�，斈嵬陆M火山巖顯著的島弧地球化學(xué)特征說(shuō)明其形成于與太平洋俯沖有關(guān)的島弧環(huán)境。
[Abstract]:There are a large number of Mesozoic (Jurassic to Cretaceous) volcanic rocks in Northeast China. The trachyandesite-rhyolite of Manitu formation in the western margin of Daxing'an Mountains is selected as the research object. The results show that they are volcanic rocks with high potassium calc-alkaline content, the content of trace elements varies greatly, the content of SiO_2 is 56.71%, the content of Na _ 2O K _ 2O is 5.92% 10.18%, the ratio of Na _ 2O / K _ 2O is 0.78% 1.3, and the mg ~ (#) is 30.6% 56.4. The results show that they are volcanic rocks with high potassium calc-alkaline content, the content of trace elements varies greatly, the content of Na _ 2O K _ 2O is 5.92% 10.18%. The rare earth element distribution map and trace element cobweb diagram of volcanic rocks in Manitu formation are obviously tilted to the right, and obvious negative anomalies of Nb,Ta,Ti,Sr and Eu (Nb~*=0.17~0.71,Sr~*=0.24~1.15,Eu~*=0.49~0.77) can be seen. The total amount of rare earth is 200 脳 10 ~ (- 6) ~ 949 脳 10 ~ (- 6). The results show that the volcanic rocks of Manitu formation are similar to those of Huolinhe volcanic rocks, and all of them are new basic lower crust mixed with a small amount of pre-existing ancient crust. The granitic magma was formed by partial melting of the new basic lower crust, and the crude andesite-trachyandesite-rhyolite of the Manitou formation was formed by the separation and crystallization of hornblende plagioclase potassium feldspar apatite ilmenite and so on. The significant island arc geochemistry of volcanic rocks in Manitu formation indicates that it was formed in the island arc environment related to Pacific subduction.
【作者單位】： 內(nèi)蒙古自治區(qū)巖漿活動(dòng)成礦與找礦重點(diǎn)實(shí)驗(yàn)室內(nèi)蒙古自治區(qū)地質(zhì)調(diào)查院;中國(guó)地質(zhì)大學(xué)(武漢)地球科學(xué)學(xué)院;中山大學(xué)地球科學(xué)與工程學(xué)院;
【基金】：國(guó)家自然科學(xué)基金項(xiàng)目(41502210) 中國(guó)地質(zhì)調(diào)查局“內(nèi)蒙古新巴爾虎右旗地營(yíng)子等六幅1∶5萬(wàn)地質(zhì)礦產(chǎn)綜合調(diào)查”子項(xiàng)目(12120115031301)
【分類號(hào)】：P542;P588.14

【相似文獻(xiàn)】

相關(guān)期刊論文 前4條

1 李世超;徐仲元;劉正宏;李永飛;王興安;張超;范志偉;;大興安嶺中段瑪尼吐組火山巖LA-ICP-MS鋯石U-Pb年齡及地球化學(xué)特征[J];地質(zhì)通報(bào);2013年Z1期

2 劉俊杰;;大興安嶺根河巖區(qū)瑪尼吐組火山巖特征及構(gòu)造環(huán)境探討[J];西部資源;2013年04期

3 李永飛;郜曉勇;孫守亮;;大興安嶺中段突泉盆地瑪尼吐組火山巖地球化學(xué)特征與~(40)Ar/~(39)Ar測(cè)年[J];地質(zhì)與資源;2013年06期

4 ;[J];;年期

相關(guān)碩士學(xué)位論文 前3條

1 于文佳;大興安嶺浩饒山地區(qū)晚侏羅世瑪尼吐組堆積序列與構(gòu)造屬性探討[D];中國(guó)地質(zhì)大學(xué)（北京）;2014年

2 杜楊;大興安嶺南段東、西坡瑪尼吐組火山巖對(duì)比研究[D];中國(guó)地質(zhì)大學(xué)（北京）;2014年

3 陶傳忠;烏蘭浩特南部瑪尼吐組火山巖的形成時(shí)代與巖石成因[D];吉林大學(xué);2015年

，

本文編號(hào)：2512475