从孢粉化石证据论冀北后城组的时代  

ON AGE OF THE HOUCHENG FORMATION IN HEBEI IN THE LIGHT OF PALYNOLOGICAL EVIDENCE

作　　者：张路锁[1,2] 张树胜 赵克明 

机构地区：[1]中国矿业大学(北京)资源与安全工程学院,北京100083 [2]河北省煤田地质局,河北石家庄050051 [3]河北省煤田地质局第四地质队,河北宣化075100 [4]河北省煤田地质勘查院,河北邢台054000

出　　处：《地层学杂志》2009年第4期407-412,共6页Journal of Stratigraphy

基　　金：河北省国土资源厅2007年矿产资源补偿费地质勘查专项(2007995023)部分成果

摘　　要：主要分布于冀北地区的后城组是一套以河流相红色砂砾岩为主的地层,此前在不同地点的该岩组中曾发现中侏罗世晚期的叶肢介、瓣鳃类和爬行动物化石和晚侏罗世的介形类和孢粉等化石。新近在蔚县后城组发现的孢粉组合与此前在宣化堰家沟、万全渔儿山西侧后城组晚侏罗世孢粉化石组合面貌具有明显的差异,时代属中侏罗世。孢粉化石证据说明冀北的后城组系—套中—晚侏罗世沉积。The Houcheng Formation distributed in northern Hebei Province is composed mainly of the fluvial red sandstone and conglomerate rocks, occasionally with fluvial sandy mudstone and intermediate and acidic volcanic beds and partly with thin coal seams. Its age was assigned on different fossil evidences to Late Middle Jurassic, Late Jurassic or early Late Jurassic. The present palynological assemblage from this formation in Yuxian is characterized by plenty of spores Cyathidites （70% in content）, with a few spore Neoraistrickia gristhorpensis, Asseretospora parva and gymnospermous pollen Classopollis, non-striate bisaccates, obviously indicating a Middle Jurassic age, and is quite different the assemblage from the same formation in Xuanhua and Wanquan which is dominate by Classopollis pollen （91% in content）, associated with some bisaccate pollen and rare Cacatricosisporites and Schizaeoisporite and was referred by Zhang Wang-ping （1984） to Late Jurassic in age. The differences between the two palynological data demonstrate that the Houcheng Formatin is a sequence from Middle to Late Jurassic age.

关 键 词：生物地层 孢粉组合 地质时代 后城组 罗系 蔚县 河北 

分 类 号：P534.52[天文地球—古生物学与地层学]