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北山造山带大红山—石板泉一带辉绿岩形成于晚古生代(305.2 Ma),地球化学特征表明具有明显的Bowen趋势,富钠贫钾,高Mg(Mg#=69),Eu正异常(δEu=1.56),HREE曲线较缓,富集高场强元素(HFSE)而亏损大离子亲石元素(LILE),属于板内拉斑玄武岩系列,岩浆源具亏损地幔和过渡型特征,但亏损程度不强,且在岩浆作用过程中可能发生过下地壳物质的混染作用,但斜长石分离作用不明显,形成于大陆裂谷环境,代表了伸展向挤压转变的构造背景。
The diabase in the Dabushan-Shibanquan area of the Beishan orogenic belt was formed in the late Paleozoic (305.2 Ma). The geochemical characteristics of the diabase are characterized by obvious Bowen tendency, rich in Na, K, Mg (= 69), and Eu positive anomaly δEu = 1.56). The HREE curve is relatively slow, enriched in HFSE and depleted in large LILEs, belonging to intraplate pullout basalt series with depleted mantle and transitional magmatic source but with loss The degree of weakness is not strong, and the mixing of crustal material may occur during the magmatic process. However, the separation of plagioclase is not obvious and formed in the continental rift environment and represents the tectonic setting of the transition from extensional to compressional.