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吉林中部烟筒山地区辉长闪长岩中锆石均呈自形--半自形,具有均匀的震荡生长条带和较高的Th/U比值(0.63～1.49),暗示其具有岩浆成因。锆石的LA--ICP--MSU--Pb定年结果表明,206Pb/238U年龄为(118±1)～(125±1)Ma(n=24),其加权平均年龄为(122±1)Ma(MSWD=4.5),代表了岩体的侵位结晶年龄—早白垩世。岩体的SiO2含量为52.41%～53.38%,TiO2=1.27%～1.95%,MgO、TFe2O3含量分别为3.34%～4.27%和8.42%～9.48%,Mg#值为44～47。Na2O含量为3.99%～4.31%,K2O含量为1.54%～1.97%,Na2O/K2O为2.05～2.75,Al2O3=16.87%～19.60%,具有相对富钠、高铝的特点。稀土元素球粒陨石标准化曲线显示其具有富含轻稀土元素(LREE)、贫重稀土元素(HREE)以及微弱的Eu的正或负异常的特点。微量元素原始地幔标准化蛛网图上,岩体具富含大离子亲石元素(Rb、Ba、Th),明显亏损高场强元素(Nb、Ta、Zr、Hf和Ti)等特点。烟筒山辉长闪长岩的原始岩浆起源于受俯冲流体交代的地幔楔的部分熔融,其形成应与古太平洋板块俯冲作用形成的类似弧后盆地性质的伸展环境有关。
The zircons from the gabbro diorites in the middle of Jilin Province show a self-shaped and semi-automorphic pattern with uniform oscillatory growth bands and high Th / U ratio (0.63 ~ 1.49) suggesting that they have magmatic origin. The results of LA - ICP - MSU - Pb dating of 206Pb / 238U from (118 ± 1) to (125 ± 1) Ma (n = 24) indicate that the weighted average age of zircons is (122 ± 1) Ma (MSWD = 4.5) represents the emplacement age of the rock mass - Early Cretaceous. The SiO2 content of the rock mass is 52.41% -53.38%, TiO2 = 1.27% -1.95%, MgO and TFe2O3 contents are 3.34% -4.27% and 8.42% -9.48% respectively, and the Mg # value is 44-47. Na2O content of 3.99% -4.31%, K2O content of 1.54% -1.97%, Na2O / K2O 2.05-2.75, Al2O3 = 16.87% -19.60%, with relatively rich in sodium and aluminum. The standard curve of the REE chondrites shows that it has the characteristics of positive or negative anomalies rich in LREE, HREE and weak Eu. The trace element primitive mantle normalized arachnoid map, the rock mass is rich in large ion lithophile elements (Rb, Ba, Th), obvious loss of high field strength elements (Nb, Ta, Zr, Hf and Ti) and other characteristics. The original magma of the Chuihshangshan gabbro origin originates from the partial melting of the mantle wedge that is subducted by the subducting fluid and is related to the extensional environment similar to that of a back-arc basin formed by the subduction of the Paleo-Pacific plate.