【摘要】 探讨冀北赤城红旗营子群是否经历了印支期的构造热事件。通过对冀北赤城红旗营子群黑云斜长片麻岩样品进行的黑云母40 Ar/39 Ar年龄测定,获得其坪年龄和等时线年龄分别为(238.63±1.44)Ma和(238.77±1.71)Ma,两者基本一致。此年龄数据是黑云斜长片麻岩在晚古生代角闪岩相区域变质作用之后所经历印支期构造热事件的记录。综合分析冀北岩浆作用及其地质年代学特征,认为它可能与区域上同时期的酸性岩浆活动有关,是后者为此次构造热事件提供了必要的热源。更多还原

【Abstract】 This paper discusses whether the Hongqiyingzi Group in Chicheng County of North Hebei underwent the Indosinian tectonothermal event or not.Biotite 40Ar/39Ar isotopic dating of the biotite plagiogneiss sample from Hongqiyingzi Group in Chicheng County of North Hebei yields a well-defined 40Ar/39Ar plateau age of 238.63±1.44 Ma and an isochron age of 238.77±1.71 Ma,respectively.This may be interpreted as the age of the later Indosinian tectonothermal event undergone by the biotite plagiogneiss after the Late Paleozoic regional amphibolite facies metamorphism.On the basis of the magmatic emplacement and its geochronological characteristics within North Hebei,this Indosinian tectonothermal event may be related to the regional acidic magmatic activity contemporaneously,and the latter provided hot sources for the former.更多还原