冀北赤城红旗营子群黑云斜长片麻岩的黑云母^(40)Ar/^(39)Ar年龄及其地质意义  

Biotite ^(40)Ar/^(39)Ar isotopic dating of the biotite plagiogneiss from Hongqiyingzi Group in Chicheng County,North Hebei, China and its geological implication

作　　者：张静[1] 倪志耀[1] 翟明国[2] 杨列坤[2] 卢俊生[3] 孔旭[1] 周新[1] 

机构地区：[1]成都理工大学地球科学学院,成都610059 [2]中国科学院地质与地球物理研究所,北京100029 [3]中国科学院研究生院地球科学学院,北京100049

出　　处：《成都理工大学学报（自然科学版）》2012年第3期290-295,共6页Journal of Chengdu University of Technology: Science & Technology Edition

基　　金：国家自然科学基金资助项目(41072050;41030316;40472041)

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。This paper discusses whether the Hongqiyingzi Group in Chieheng 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 welldefined 40Ar/39Ar plateau age of 238. 63±1. 44 Ma and an isoehron age of 238. 77 ±1. 71 Ma, respectively. This may be interpreted as the age of the later Indosinian teetonothermal 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 magmatie activity contemporaneously, and the latter provided hot sources for the former.

关 键 词：黑云母40Ar/39Ar年龄 印支期 构造热事件 黑云斜长片麻岩 红旗营子群 冀北 赤城 

分 类 号：P597.3[天文地球—地球化学]