鄂尔多斯盆地伊利石K-Ar等时线图解与年龄  

The K-Ar Isochron Diagram and Ages of Illites from The Ordos Basin

作　　者：赵孟为 汉斯.阿伦特 克劳斯.魏玛 

机构地区：[1]德国哥廷根大学地质与岩石圈动力学研究所

出　　处：《沉积学报》1997年第4期148-151,共4页Acta Sedimentologica Sinica

摘　　要：根据伊利石４０Ｋ－４０Ａｒ和４０Ｋ／３６Ａｒ－４０Ａｒ／３６Ａｒ等时线图解与年龄验证了利用常规Ｋ－Ａｒ测年法所确定的鄂尔多斯盆地的两期成岩作用时代。分析结果表明，伊利石Ｋ－Ａｒ时钟是一个封闭体系，故能够用来确定沉积岩的成岩作用时代；常规Ｋ－Ａｒ年龄所揭示的侏罗纪（１７０～１６０Ｍａ）和志留—泥盆纪（４２０～３７０Ｍａ）成岩作用时代是可靠的；The principle of KAr isochron method was introduced in this paper.The kAr isochron data of illites from the Ordos basin were successfully used to evaluate the two distinct diagenetic stages identified by conventional KAr dating.Both the PermianTriassic and CambrianOrdovician samples yield well defined40K40Ar isochrons,which indicate intercepts almost equal to zero and similar isochron ages to the conventional KAr ages.In addition,the PermianTriassic samples gave also a well defined40K/36Ar40Ar/36Ar isochron,which yields an intercept of nearly the atmospheric argon ratio(295.5)and a similar isochron age to the conventional KAr ages.These facts indicated that the illite KAr clock belongs actually to a closed system,and thus can validly be used to determine diagenetic ages of sedimentary rocks.The Jurassic(170￣160 Ma)and SilurianDevonian(420￣370 Ma)diagenetic stages revealed by conventional KAr data were proved to be reliable.KAr isochron methods can supply additional information to evaluating the validity of conventional KAr isochron methods.It can also Provide improved constrints on interpreting KAr data and their geological meanings.

关 键 词：伊利石 等时线图解 年龄 成岩作用 盆地 钾-氩 

分 类 号：P588.22[天文地球—岩石学]