矿产与地质
礦產與地質
광산여지질
MINERAL RESOURCES AND GEOLOGY
2014年
5期
596-604
,共9页
栗木%淡色花岗岩%构造环境%后碰撞
慄木%淡色花崗巖%構造環境%後踫撞
률목%담색화강암%구조배경%후팽당
leucogranite%lithogeochemical characteristic%tectonic setting%post-collision
根据岩石高硅(SiO 2=72.30%~75.45%),全碱含量高[(Na2 O + K2 O)>7%,平均值为7.77%)],高铝(Al2 O 3≥14%,平均值为14.51%),ASI >1.1,CIPW 标准矿物刚玉(C)2.43%~4.75%,稀土总量低(3.68×10-6~16.48×10-6),轻稀土弱富集(L/H 为1.71~2.81),δEu 值低(0.01~0.21)的特征,确定栗木花岗岩属淡色花岗岩,可进一步命名刚玉淡色花岗岩。同时根据岩石的铕异常、稀土元素和微量元素的地球化学特征,结合构造判别图解,笔者认为栗木花岗岩是在后碰撞的挤压构造环境下,前寒武系或寒武系深层位的泥砂质碎屑岩在相对高压低温的条件下经部分熔融的产物。
根據巖石高硅(SiO 2=72.30%~75.45%),全堿含量高[(Na2 O + K2 O)>7%,平均值為7.77%)],高鋁(Al2 O 3≥14%,平均值為14.51%),ASI >1.1,CIPW 標準礦物剛玉(C)2.43%~4.75%,稀土總量低(3.68×10-6~16.48×10-6),輕稀土弱富集(L/H 為1.71~2.81),δEu 值低(0.01~0.21)的特徵,確定慄木花崗巖屬淡色花崗巖,可進一步命名剛玉淡色花崗巖。同時根據巖石的銪異常、稀土元素和微量元素的地毬化學特徵,結閤構造判彆圖解,筆者認為慄木花崗巖是在後踫撞的擠壓構造環境下,前寒武繫或寒武繫深層位的泥砂質碎屑巖在相對高壓低溫的條件下經部分鎔融的產物。
근거암석고규(SiO 2=72.30%~75.45%),전감함량고[(Na2 O + K2 O)>7%,평균치위7.77%)],고려(Al2 O 3≥14%,평균치위14.51%),ASI >1.1,CIPW 표준광물강옥(C)2.43%~4.75%,희토총량저(3.68×10-6~16.48×10-6),경희토약부집(L/H 위1.71~2.81),δEu 치저(0.01~0.21)적특정,학정률목화강암속담색화강암,가진일보명명강옥담색화강암。동시근거암석적유이상、희토원소화미량원소적지구화학특정,결합구조판별도해,필자인위률목화강암시재후팽당적제압구조배경하,전한무계혹한무계심층위적니사질쇄설암재상대고압저온적조건하경부분용융적산물。
Based on the facts that rocks have high silicon (SiO 2 =72.30%~75.45%),total alkali content is high [(Na2 O+K2 O)>7%,average=7.77%],aluminum is high (Al2 O 3 ≥14%,average=14.5 1%),ASI>1.1,CIPW norm mineral is corundum (C)2.43%~4.75%,total REE content is low (3.68×10 -6 ~1 6.48× 10 -6 ),LREE is slightly enriched (L/H is 1.71 ~2.81),and δEu value is low (0.01 ~0.21 ),it is verified that granites in Limu is a kind of leucogranite.Furthermore it can be named as corundum leucogranite.Mo-reover,according to europium anomaly and geochemical characters of REEs and trace elements,and on the basis of tectono-discrimination diagram,it is believed that granites in Limu is a product of partial melting of argillo arenaceous clastic rocks at Precambrian or Cambrian deep depth under the conditions of high pressure and low temperature in the post-collisional compressive tectonic environment.
