辽西中生代陆内底侵作用背景下形成的安山岩

本文选择了辽西地区中生代230Ma、190Ma、159Ma、123Ma、116Ma等不同时期的安山岩及其所含的辉石,通过岩石学、岩相学、地球化学和同位素的研究,发现它们同时具有壳源和幔源的特征,而且大多数单斜辉石记录了两种或多种熔体的相互作用。据此作者认为安山岩是壳幔岩浆混熔成因的,而如此长期的热演化与大陆内部伸展背景下的底侵作用有关。

Mesozoic intracontinental andesites formed by underplating in west Liaoning province

Petrologic,petrographical,geochemical,and isotopic researches of Mesozoic andesites and contained pyroxenes are carried out,with the samples of different period(230Ma,190Ma,159Ma,123Ma,and 116Ma)collected from the west Liaoning Province.The results indicate that most of those andesites possess features of both and crust-source magma and mantle-source magma, and that most of the clinopyroxenes record interaction between two or more melts.Therefore the authors conclude that the andesites are resulted from mixing of magmas originated from the crust and the mantle,a long-term thermal evolution related to intracontinental underplating under extensional tectonic settings.