滇东北会泽地区震旦系与寒武系界线讨论  

A DISCUSSION ABOUT THE BOUNDARY BETWWEN SINIAN AND CAMBRIAN IN HUIZE AREA,NE YUNNAN

作　　者：陈庆松 杨润柏[1] CHEN Qing-song;YANG Run-bai(Au Geological Team 10,People s Armed Police of China,Kunming 650000)

机构地区：[1]中国人民武装警察部队黄金第十支队

出　　处：《云南地质》2019年第2期155-161,共7页Yunnan Geology

摘　　要：滇东北会泽地区广泛岀露震旦纪-寒武纪过渡地层,主体为一套浅海相碳酸岩夹碎屑岩。近期开展的1∶5万区域地质矿产调查,首次在会泽地区五星乡一带灯影组上部发现凝灰岩(斑脱岩)夹层,并进行了SHRIMP锆石U-Pb测年,获得其206Pb/238U年龄加权平均值为538±5Ma,其表明灯影组上段上部的沉积时代为早寒武世梅树村期。此外,通过与邻区前寒武系-寒武系界线对比研究,会泽地区震旦系与寒武系界线应置于该凝灰岩(斑脱岩)底界,即灯影组上段非正式地层单位(中谊村段)底部。The transitional strata between Sinian and Cambrian are widely outcropped in Huize area,NE Yunnan,which are mainly a suit of neritic carbonate rock with the intercalary clastic rocks.In recent 1∶50000 regional survey of geology and mineral resources,the tuff intercalary bed(b)entonite is discovered first in Wuxingxiang area of Huize,its 206 Pb/238 U weighted mean age 538±5 Ma of SHRIMP zircon U-Pb dating,which shows Dengying Formation Upper Member upper part age is Early Cambrian Meishucun stage.Moreover,we think the boundary between Sinian and Cambrian in Huize area must be the bottom of this tuff(b)entonite,ie the bottom of informal stratigraphic unit(Zhongyicun Member)according to the correlation with nearby boundary between pre-Cambrian-Cambrian.

关 键 词：凝灰岩 锆石U-PB测年 地层界线 云南会泽 

分 类 号：P534[天文地球—古生物学与地层学]