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通过对大兴安岭地区侏罗系与白垩系之间不整合面的讨论,以地层区域对比及同位素测年数据等信息确定其界线,达到本区侏罗系与白垩系界线的可识别性、客观性和稳定性之目的.同时,对该区主要地层形成的大地构造环境的研究,认为土城子组是碰撞造山后伸展阶段形成的一套陆相红层,也是侏罗纪结束的标准层;而满克头鄂博组、玛尼吐组和白音高老组则是碰撞造山后垮塌阶段形成的火山地层.以大规模火山爆发为特征,本区开始了白垩纪地壳演化阶段.侏罗系与白垩系界线位于土城子组与满克头鄂博组之间,二者界线以区域不整合(假整合)为特征,不整合面形成于碰撞造山后伸展与垮塌的转换时期.
Through the discussion of the unconformity between the Jurassic and Cretaceous in the Greater Khingan Range, the boundary between the Jurassic and the Cretaceous in the Greater Xing’an Mountains is determined, and the boundaries of the Jurassic and Cretaceous are defined by the stratigraphic regional contrast and isotopic dating data, so the identifiability and objectivity And stability.At the same time, the study on the tectonic setting of the earth formed by the main strata in this area shows that the Tuchengzi Formation is a terrigenous red layer formed after the collision orogeny and also the standard layer ending Jurassic. The Obo Formation, Manitou Formation and Baiyinogoshao Formation are volcanic formations formed during the post-orogenic collapses, characterized by large-scale volcanic eruptions, where the Cretaceous crustal evolution began in the Jurassic and Cretaceous The boundary line is located between the Tuchengzi Formation and the Manke Obo Formation. The boundaries between the two are characterized by regional unconformity (fake integration), and the unconformity is formed during the transition from extension to collapse after collision orogeny.