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南祁连党河南山地区发育一些小规模的煌斑岩脉,岩脉穿插于前泥盆纪地层及岩体中,岩石w(SiO_2)=46.93%~56.82%,w(K_2O)=0.64%~4.12%,属钙碱性系列煌斑岩.稀土元素总量较低(1.534 5×10~(-4)~2.744 9×10~(-4)),轻稀土富集,重稀土相对亏损.强烈富集大离子亲石元素(Rb、Ba、La、Ce、Sr)和U、Pb,亏损高场强元素(Nb、Ta、Zr、Hf).岩石w(~(87)Sr)/w(~(86)Sr)=0.713 716~0.716 950,εNd(t)=-6.713 9~-8.3986,w(~(143)Nd)/w(~(144)Nd)=0.512 036~0.512 117,具有高Sr低Nd的特征.煌斑岩源岩具岛弧钙碱性玄武岩的性质,源区可能为EMⅠ型富集地幔.煌斑岩的形成指示党河南山地区在海西早期已经处于碰撞后的伸展阶段.
Some small-scale lamprophyre veins were developed in the Henan Qilian party Henan area. The veins were intercalated into the Pre-Devonian strata and rock mass with rock (SiO 2) = 46.93% -56.82% and w (K 2 O) = 0.64% ~ 4.12%, belonging to the calc-alkaline series lamprophytes.The total amount of rare earth elements is relatively low (1.534 5 × 10 -4 ~ 2.744 9 × 10 -4) (Rb, Ba, La, Ce, Sr) and U, Pb and depleted high field strength elements (Nb, Ta, Zr and Hf) w (~ (86) Sr) = 0.713 716 ~ 0.716 950, εNd (t) = -6.713 9 ~ -8.3986, w (~ (143) Nd) , With the characteristics of high Sr and low Nd.The lamprophyre source rocks have the property of island arc ca-alkaline basalts, and the source area may be the EMⅠtype enriched mantle.The formation of lamprophyre indicates that the party Henan Nanshan area was already in the early Hercynian After the collision extension stage.