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吉林省南部夹皮沟地块原称晚太古绿岩盆地 ,以盛产金矿遐尔于世。新近调查资料表明 ,它是由表壳岩 -TTG岩系组成的一太古宙高级变质地体 ,并有别于南侧之龙岗陆块。表壳岩岩石化学特征显示 :其岩石组成中 ,不存在典型的科马提岩 ;变质深成侵入岩为典型的TTG岩浆组合 ;在Na -Ca -K图解中表现为以英云闪长岩—奥长花岗岩演化方向为主。其稀土特征显示为总量相对较低 ,轻稀土富集 ,δEu为轻微正异常或无异常 ,图谱与J G Arthoqu (1982 )所做高铝型英云闪长岩—奥长花岗岩的模式曲线相类似 ,属高铝的大陆型TTG岩系。夹皮沟岩群表壳岩的年龄 ,依据王义文 (1981)用矿石铅二次等时线年龄求矿源层年龄 ,可获得 37亿年、 35亿年、 31亿年 3个数值。 (1984 )利用矿石铅同位素三阶段同位素模式 ,求出矿源层年龄为 31亿年～ 2 8亿年 ,TTG岩系年龄 ,Sm -Nd等时线为 2 6 39Ma ,Rb -Sr等时线为 2 516Ma ,U -Pb的一致线年龄为 2 56 5Ma。表明其形成或主要一次构造热事件发生在晚太古时期 ,亦即与南侧龙岗陆块的拼贴时期。沿夹皮沟(板庙子—二道沟 )韧性剪切拼贴带侵位的钾长花岗岩 ,U -Pb等时线年龄 2 4 57Ma。
Jiapigou block in the southern part of Jilin Province was originally called Late Archean Greenstone Basin, in order to abound in gold abounds in the world. According to recent survey data, it is an Archean high-grade metamorphic terrane composed of epikarst-TTG rock series and different from the Longgang block on the south side. The rock petrochemical characteristics of the crust indicate that there is no typical komatiite in the rock composition, the metamorphic deep intrusive rocks are typical TTG magmatic assemblages, and the Na-Ca-K diagram is characterized by the diorite The main evolutionary direction of granitic granites. The rare earths are characterized by a relatively low total amount, light rare earth enrichment, a slight positive anomaly of δEu, or no abnormalities. The pattern is consistent with the pattern curve of high-Al-type amphibolite-palaeite granites from JG Arthoqu (1982) Similar, is a continental TTG rock series of high aluminum. According to the age of the crustal rocks of Jiapigou Group, Wang Yiwen (1981) obtained the ages of 3.7 years, 3.5 billion years and 3.1 billion years according to the age of the second isochron age of ore lead. (1984) used the three-phase isotope pattern of lead isotopes of ore to determine that the age of the source rock was between 3.1 billion and 2.8 billion years. The age of the TTG rocks, the Sm-Nd isochron and the Rb-Sr isochron was 26939Ma and The coincident line ages of 2 516 Ma and U -Pb are 2 56 5 Ma. Indicating that its formation or major thermal events occurred in the late Archean, that is, with the South Longgang landmass collage period. The potash-bearing granite was emplaced along the Jiapigou (Banmiao-Erdaogou) ductile shear collage with U-Pb isochron age of 2457 Ma.