内蒙古四子王旗早白垩世深源捕虏体的发现及意义  

Significances of Deep-Seated Xenolith in Cretaceous Basalt of Inner Mongolia

作　　者：许绚[1] 吴泰然[1] 张双涛[1] J.Byamba A.Amarjargal 王时麒[3] 李忠权 

机构地区：[1]造山带与地壳演化教育部重点实验室,北京大学北京100871 [2]蒙古国立大学地球科学学院,乌兰巴托210000 [3]北京大学地球与空间科学学院,北京100871

出　　处：《北京大学学报（自然科学版）》2005年第4期563-569,共7页Acta Scientiarum Naturalium Universitatis Pekinensis

基　　金：国家自然科学基金(40072074)资助项目

摘　　要：内蒙古四子王旗地区地处华北板块北缘,与西伯利亚板块的接合部,其早白垩世橄榄玄武岩中发现大量下地壳麻粒岩捕虏体,并可见辉石、长石捕虏晶。寄主岩石KAr同位素年龄在108.6～128.4Ma之间。四子王旗地区下地壳捕虏体的发现对研究华北板块北缘中生代构造格局转化过程中深部壳幔的相互作用及物质成分的演变具有重要意义,为华北板块中生代末岩石圈拆沉事件提供了证据。Siziwangqi of Inner Mongolia is located on the north margin of North China Craton, the junction of North China Craton and Siberia. Granulite xenoliths are found there in Cretaceous basalt. These xenoliths are mainly plagioclase-pyroxenite. The K-Ar isotopic dating of the basalt is between 108.6-128.4 Ma. These granulite xenoliths are not only important for understanding the composition and interaction between the lower lithosphere and the mantle, but also direct evidence for Mesozoic delamination of North China Craton.

关 键 词：早白垩世 下地壳 麻粒岩捕虏体 四子王旗 

分 类 号：P548.245[天文地球—构造地质学]