發(fā)布時(shí)間：2019-08-14 15:14

【摘要】：阿爾金奇克山地區(qū)侵入于地層中的斜長(zhǎng)角閃巖原巖為輝長(zhǎng)巖,巖石地球化學(xué)組成顯示斜長(zhǎng)角閃巖的SiO_2和Al_2O_3含量較高為49.29%~51.03%和12.27%~14.49%,Na_2O+K_2O含量低為2.35%~4.37%,MgO和Mg~#值為6.48%~10.12%和48.7~59.6,具Eu負(fù)異常,樣品的MgO對(duì)SiO_2、Al_2O_3、TiO_2及Cr-Rb和Rb/Nb-Rb/Zr關(guān)系圖顯示明顯相關(guān)性,表明其為地幔巖漿經(jīng)分異演化形成。巖石富集Rb、Th和U,虧損Nb、Sr和P,且Th/Ta為1.05~2.771,Nb/La為0.88~1.02,多小于1,顯示巖石在演化過(guò)程中受到了地殼輕微混染,推斷巖石形成于板內(nèi)伸展環(huán)境。利用LA-ICP-MS微區(qū)原位定年獲得斜長(zhǎng)角閃巖~(206)Pb/~(238)U-~(207)Pb/~(235)U諧和年齡503±5 Ma和~(206)Pb/~(238)U加權(quán)平均年齡為479±6 Ma,該年齡段為阿爾金峰期變質(zhì)階段,指示巖石形成于479 Ma以前。
[Abstract]:The plagioclase protolith invaded into the strata in Aljinqikeshan area is gabbro. The geochemistry composition shows that the SiO_2 and Al_2O_3 contents of plagioclase hornblende are 49.29% 5.03% and 12.27% 14.49%, while the Na 2O K 2O content is 2.35% 4.37%, and the Eu and Mg~# values are 6.48% 10.12% and 48.7% 5.96, respectively. The MgO of the sample has negative anomalies of SiO_2, and the rock geochemistry composition shows that the plagioclase content of plagioclase hornblende is 49.29% 5.03% and 12.27% 14.49%, while that of Na 2O K 2O is 2.35% 4.37%. The relationship between Al_2O_3,TiO_2 and Cr-Rb and Rb/Nb-Rb/Zr shows obvious correlation, indicating that it is formed by differentiation and evolution of mantle magma. The rocks are enriched in Rb,Th and U, deficient in Nb,Sr and P, and Th/Ta is 1.05 鈮，

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