马厂箐富碱斑岩体是马厂箐铜钼矿的主要赋矿围岩,属于哀牢山-金沙江富碱侵入岩带的组成部分.岩体为喜马拉雅期的富碱杂岩体,岩性主要为花岗斑岩、二长斑岩和正长斑岩.稀土元素丰度与分配在不同岩石中是不一样的,马厂箐岩体中∑REE为106.29×10-6～297.9×10-6,LR/HR为8.04～23.99,La/Yb为9.86～75.16,La/Sm为2.98～11.82,Gd/Yb 28.42～141.31,δEu值为0.72～0.88.在球粒陨石标准化稀土模式图上,表现为左高右低的较平滑曲线,轻微的Eu负异常.表明岩体物源来自于地幔或地幔与地壳的共同作用,为壳幔混熔的产物.%Machangqing alkali-rich porphyry is the main ore-bearing wall rock of Machangqing copper-molybdenum ore. And it belongs to part of Ailao Mountain-Jinsha River alkali-rich intrusive rock zone. The rock body is alkali-rich complex of Himalaya Phase. And the lithological characters mainly feature granite porphyry, ivernite and orthophyre. The abundance and distribution of these rare earth elements vary in different rocks. In the Machangqing rock body, the ∑REE is 106.29-297. 9×l0-6, LR/HR 8.04-23. 99, La/Yb 9.86-75.16, La/Sm 2. 98-11.82, Gd/Yb 28.42-141.31 and the δEu 0. 72-0. 88. On the figure of chondrite normalized REE pattern, it appears to be a comparatively smooth curve with the left higher than the right and Eu slightly negative anomaly. It indicates that the rocks originate from the action of mantle or combined action of mantle and crust and they are blend-melt products of mantle and crust.
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