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水泉沟碱性正长岩杂岩体侵入于太古宇桑干群变质岩中，岩体主要由碱性长石正长岩、角闪碱长正长岩、正长岩、石英碱长正长岩等组成，属碱性岩系列，在岩石的石英颗粒中见有熔融包体的存在。岩石的稀土元素分布模式呈平滑的右倾模式，无明显的铕异常。岩石的Ｐｂ同位素组成为２０６Ｐｂ／２０４Ｐｂ＝１６．４５７～１８．２８６、２０７Ｐｂ／２０４Ｐｂ＝１５．２７０～１５．４７２、２０８Ｐｂ／２０４Ｐｂ＝３６．５３９～３７．３９３，石英的δ１８Ｏ值为８．０‰～８．５‰，（８７Ｓｒ／８６Ｓｒ）ｉ≈０．７０５，岩石的ｔＤＭ为１．６～１．９Ｇａ，εＮｄ（ｔ）为－７．４５～－１３．１，明显大于区域基底的εＮｄ（ｔ）值（－２０±）。以上结果表明，岩体为上地幔和下地壳物质部分熔融的产物。岩体角闪石３９Ａｒ－４０Ａｒ年龄３２７Ｍａ，为海西期岩浆作用的产物
The Shuiquanigou alkaline syenite complex intrusions into the Swire metamorphic rocks of the Yushugan Group in the Archean. The intrusive rocks are mainly composed of alkali feldspar syenite, amphetamine long syenite, syenite and quartz alkaloid Rock and other components, is a series of alkaline rocks, rocks in the quartz particles in the presence of melting inclusions. The REE distribution pattern of rock shows a smooth right-dip pattern with no obvious europium anomaly. The Pb isotopic compositions of the rocks are 206Pb / 204Pb = 16.457 ~ 18.286, 207Pb / 204Pb = 15.270 ~ 15.472, 208Pb / 204Pb = 36.539 ~ 37.393, and the δ18O value of quartz is 8.0 ‰ ~ 8.5 ‰, (87Sr / 86Sr) i≈0.705, the tDM of rocks is 1.6 ~ 1.9Ga and the εNd (t) is -7.45 ~ -13.1, which is obviously higher than that of the regional basement εNd (t) value (-20 ±). The above results show that the rock mass is the product of partial melting of the material of the upper mantle and the lower crust. The amphibole rock 39Ar-40Ar age is 327Ma, which is the product of Hercynian magmatism