【摘要】 <正> 陕西洛南—河南栾川一带,断续分布着一套碱钙性—碱性火山岩(图1)。1∶20万洛南幅、栾川幅地质图和1∶50万东秦岭地质图将其划为片理化正长斑岩,时代置早元古代。以后的调查者也都将其作为侵入体对待。更多还原

【Abstract】 The alkaline volcanic rocks of the Baoshangou formation and Dahongkou formation occur respectively in the areas of Luonan,Shaanxi and Luanchuan, Henan,they are composed of trachytic lava and tuff interbedded with miner volcanic breccia as well as normal sediments.According to stritigraphic horizon contact relation and isotopic geologic age of these volcanic rocks,the age must be Upper Proterozoic Subera.Based on their petrological and petrochemical characteristics of combinsed with the analyses of tectonic environment,these volcanics may belong to the products of rift zone transitional from the intracontinental type to the mobile continental margin.更多还原