Tectonically Unsong-ri lies on the northern limb of the eastwest-trending Hwangju Syncline, and here the Rungri Formation is a tectonically stable and thick succession.Based on lithology, the Yonthan Group can be divided into two formal units-the Pirangdong and the Rungri Formations.The fossiliferous unit lies in the upper part of the Rungri Formation and consists of dark and gray green shales.The specimens of Vendotaenia antiqua are commonly, smoothly curved and lie parallel to the bedding planes.Widths of the preserved fossils range from 0.5 mm to 2.0 mm, sometimes reaching 3.5 mm and sometimes exhibit dichotomous branching of some individuals on a single bedding surface.After branching, the width does not change.Ribbon-like organisms reach lengths of up to 10 cm, sometimes up to 15 cm, but, in life, were presumably longer.No complete fossils have been found.No clearly differentiated terminations were observed in the hundreds of specimens collected.In hand specimens, the majority of the fossils stand out clearly because of their strong color contrast to the surrounding matrix individuals are generally either rust or brown in color.The surrounding matrix of specimens is clayrich infill material differs from matrix predominantly in its elevated C and Fe abundances.SEM analyses of the specimens show distinctive longitudinal striations.Vendotaenia antiqua commonly occurs in dense populations.The high abundances and random orientations of these fossils suggest that benthic populations were preserved more or less in place.A striking feature of the preserved populations on almost all bedding planes of the upper Rungri Formation is that the specimens tend to be of near constant width on any single bedding plane-width varies between bedding planes, but rarely within them.Morphologically similar Vendotaenia-like specimens occur in other Ediacaran, including localities in Namibia, the East European Platform, China, and Brazil.Hence, the Rungri Formation of the Yonthan Group is likely correlatable to the upper Ediacaran strata globally（including Nama Group, Kotlinian Group, Doushantuo and Dengying Formations, and Tamengo Formation） on the basis of Vendotaenia.The new finds from the Rungri Formation in the Yonthan Group epitomize an important paleontological discovery on the Korea-China Craton.
类型: 国际会议
作者: Kwang-Sik SO,Chol-Guk WON,Jun MA,Se-Chan KIM
来源: 第一届亚洲古生物学大会—暨中国古生物学会成立90周年纪念 2019-11-17
年度: 2019
分类: 基础科学
专业: 生物学,地质学
单位: Department of Paleontology, Faculty of Geology, Kim Il Sung UniversityOffice of Human evolution development, Faculty of History, Kim Il Sung University
分类号: Q911.2
页码: 24-25
总页数: 2
文件大小: 113k
下载量: 1
本文来源: https://www.lunwen90.cn/article/d555ccca005b90dbcc9ec6f0.html