内蒙古东部科尔沁右翼中旗地区出露一套古生代浅变质地层,长期以来在缺少大化石依据的前题下,仅依据岩性组合的区域对比,将其划归二叠系.近年结束的1:5万区调,在该套地层中发现9属疑源类化石.将该9属疑源类化石与国内外已知时代地层的疑源类化石进行了对比研究,认为研究区发现的疑源类化石组合显示旱寒武世的生物组合面貌,地层时代应厘定为早寒武世.研究区下寒武统的确定,为进一步研究大兴安岭中南段古生代地质构造演化提供了新的资料.%There is a set of Paleozoic low-grade metamorphosed strata found in Horqin Right Wing Middle Banner area of eastern Inner Mongolia. Due to lack of macrofossils, the low-grade metamorphosed strata were assigned to Permian only on the basis of regional correlation of lithologic combinations. During the 1:50000 regional geological survey completed in recent years, 9 genera acritarch fossils were found in the strata. Based on a comparative study of the 9 genera acritarch fossils and the known acritarch assemblages of Paleozoic strata at home and abroad, the authors have reached the conclusion that the acritarch fossil assemblage discovered in the study area should have the biological combination features of the Early Cambrian, and hence the stratigraphic age should be Early Cambrian. The identification of Lower Cambrian strata in the study area can provide new information for further study of Paleozoic tectonic evolution in the middle-southern segment of the Da Hinggan Mountains.
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