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望天鹅火山活动从早到晚分为三期：①长白期以粗面玄武岩为主，少量碱性玄武岩和玄武质粗安岩；②望天鹅期又分早晚两个亚期，早期玄武质粗安岩和粗面岩，晚期碱性流纹岩；③红头山期碱性流纹岩。望天鹅火山岩的岩石学、ＲＥＥ、不相容元素和Ｎｄ、Ｓｒ、Ｐｂ同位素（１４３Ｎｄ／１４４Ｎｄ、８７Ｓｒ／８６Ｓｒ、２０６Ｐｂ／２０４Ｐｂ分别变化于０．５１２５６７～０．５１２６４２、０．７０５１９８～０．７１６７４２和１７．４３４～１７．９３４），揭示了岩浆源区明显受洋壳的俯冲和壳幔混合混染，三期火山岩具有共同的岩浆源区和紧密的成因演化关系，分离结晶作用控制了岩浆的演化过程。原始碱性系列玄武质岩浆经橄榄石、辉石的结晶分异，向粗面玄武岩演化；粗面玄武岩经斜长石强烈的结晶分离作用，还有辉石、钛铁氧化物和磷灰石的分离结晶作用形成具显著Ｅｕ、Ｓｒ、Ｂａ、Ｔｉ、Ｐ负异常的碱性流纹岩，导致本区火山岩缺失中性（ＳｉＯ２＝５７％～６３％）的安山岩和粗安岩，呈现双峰式火山岩组合的特点。
Wang Swan volcanic activity from morning to night is divided into three phases: ① Changbai period mainly of coarse basalts, a small amount of basic basalt and basaltic rock; ② Wang Swan period is divided into two sub-morning and evening, the early basaltic crude On rock and Rough rock, late alkaline rhyolite; ③ Redhead period alkaline rhyolite. The petrology, REE, incompatible elements and Nd, Sr and Pb isotopes (143Nd / 144Nd, 87Sr / 86Sr and 206Pb / 204Pb) of the Mongolian volcanic rocks vary from 0.512567 to 0.512642 and from 0.705198 to 0.716742 And 17.434 ~ 17.934), revealing that the magmatic source area was obviously subducted by the oceanic crust and mixed with the crust and mantle. The third-stage volcanic rocks have a common magmatic source zone and close genetic evolution. The separation and crystallization control the magma The evolutionary process. The primitive basaltic series of basaltic magmas differentiated from the olivine and pyroxene to the coarse basalts. The rough basalts were strongly crystallized by plagioclase, and pyroxene, titanium iron oxide and apatite The results show that the volcanic rocks in this area are lack of neutral (SiO2 = 57% ~ 63%) andesite and coarse andesite, Characteristics of peak volcanic assemblages.