宁夏工程技术
寧夏工程技術
저하공정기술
NINGXIA ENGINGEERING TECHNOLOGY
2012年
3期
206-213,219
,共9页
贺兰山%黄旗口花岗岩%SHRIMP%U—Pb定年%岩石地球化学特征%形成构造环境
賀蘭山%黃旂口花崗巖%SHRIMP%U—Pb定年%巖石地毬化學特徵%形成構造環境
하란산%황기구화강암%SHRIMP%U—Pb정년%암석지구화학특정%형성구조배경
Helanshan area%Huangqikou granite%SHRIMP U-Pb dating%lithogeochemical characteristics%formation structural environment
通过锆石SHRIMPU—Pb测年,获得了(2003±10)Ma和(1976±17)Ma两组同位素年龄,表明贺兰山黄旗口花岗岩形成时代为古元古代.黄旗口花岗岩岩石化学类型属钙性-钙碱性岩系,属过铝的岩石类型;稀土元素总量中等,轻、重稀土分异显著,轻稀土相对富集,重稀土相对亏损,具铕负异常.岩石化学特征表明,黄旗口花岗岩具有壳源型花岗岩的一些特征,属S型花岗岩,是上地壳深熔岩浆侵入而形成的花岗岩类,岩石化学图解表明,应形成于大陆碰撞造山环境.
通過鋯石SHRIMPU—Pb測年,穫得瞭(2003±10)Ma和(1976±17)Ma兩組同位素年齡,錶明賀蘭山黃旂口花崗巖形成時代為古元古代.黃旂口花崗巖巖石化學類型屬鈣性-鈣堿性巖繫,屬過鋁的巖石類型;稀土元素總量中等,輕、重稀土分異顯著,輕稀土相對富集,重稀土相對虧損,具銪負異常.巖石化學特徵錶明,黃旂口花崗巖具有殼源型花崗巖的一些特徵,屬S型花崗巖,是上地殼深鎔巖漿侵入而形成的花崗巖類,巖石化學圖解錶明,應形成于大陸踫撞造山環境.
통과고석SHRIMPU—Pb측년,획득료(2003±10)Ma화(1976±17)Ma량조동위소년령,표명하란산황기구화강암형성시대위고원고대.황기구화강암암석화학류형속개성-개감성암계,속과려적암석류형;희토원소총량중등,경、중희토분이현저,경희토상대부집,중희토상대우손,구유부이상.암석화학특정표명,황기구화강암구유각원형화강암적일사특정,속S형화강암,시상지각심용암장침입이형성적화강암류,암석화학도해표명,응형성우대륙팽당조산배경.
By using dating technique of zircon SHRIMP U-Pb, the isotopic ages of (2 003±10)Ma and (1 976±17)Ma from Huangqikou granite were obtained, it shows that Huangqikou granite of Helanshan were formed in paleoproterozoic. The geochemical types of Huangqikou granite belongs to calcium and calc-alkali series, which is peraluminous type. The total volume of rare earth elements is moderate; and content of light and heavy rare earth elements is different significantly, content of light rare earth elements is richer and content of heavy rare earth elements is shorter relatively, Eu is negative anomalies. Geochemcial characteristics indicate that Huangqikou granite has some characteristics of the crustal type granite and belong to the S-type granite, were formed by the intrusion of upper crust anatcctic magma. Rock chemical diagrams show that the Huangqikou granite were formed in a continental collision orogenic environment.