In 1997 and 1998, hundreds of specimens of megascopic carbonaceous compressions or algal fossils were found from - 1800-million-year old Changzhougou Formation, which is the lowermost unit of the latest Palaeoproteroz...In 1997 and 1998, hundreds of specimens of megascopic carbonaceous compressions or algal fossils were found from - 1800-million-year old Changzhougou Formation, which is the lowermost unit of the latest Palaeoproterozoic Changcheng Group (~1 600-1 800 Ma) in the Xinglong-Kuancheng areas at the middle Yanshan Range, North China. They are discoid, ellipsoid and sausage-like, namely shaped like Chuaria Shouhsiennia (Ellipsophyta) and Tawuia. By adopting HF acid-resistant maceration coupled with scanning electron microscope and petrologic section, the authors made a preliminary research on the histology for some circular and ellipsoid carbonaceous compressions, namely Chuaria- and Shouhsienia-llke forms, in addition to their morphology. The following three types of multicellular tissues have been found in the fragments of them: colony-like, pseudoparenchyma-like and parenchyma-like. All of the new data about multicelluar tissues not only supply a very important basis in histology to determine the展开更多
The paleoflow direction of the basal conglomerate of the Changzhougou formation is obtained by the paleocurrent analysis of certain sedimentary structures,and the ancient sedimentary environment of the Qian’an Region...The paleoflow direction of the basal conglomerate of the Changzhougou formation is obtained by the paleocurrent analysis of certain sedimentary structures,and the ancient sedimentary environment of the Qian’an Region is determined by observing the psephicity and gradation of gravel in conglomerate.The results show that the paleoflow direction is from northwest to southwest,and the paleocurrent data manifest a single-peak style in a rose diagram.The average paleoflow direction in the Qian’an region is 265°.The basal conglomerate is of littoral facies,and the sediments of conglomerates are mainly sourced from Shanhaiguan.展开更多
文摘In 1997 and 1998, hundreds of specimens of megascopic carbonaceous compressions or algal fossils were found from - 1800-million-year old Changzhougou Formation, which is the lowermost unit of the latest Palaeoproterozoic Changcheng Group (~1 600-1 800 Ma) in the Xinglong-Kuancheng areas at the middle Yanshan Range, North China. They are discoid, ellipsoid and sausage-like, namely shaped like Chuaria Shouhsiennia (Ellipsophyta) and Tawuia. By adopting HF acid-resistant maceration coupled with scanning electron microscope and petrologic section, the authors made a preliminary research on the histology for some circular and ellipsoid carbonaceous compressions, namely Chuaria- and Shouhsienia-llke forms, in addition to their morphology. The following three types of multicellular tissues have been found in the fragments of them: colony-like, pseudoparenchyma-like and parenchyma-like. All of the new data about multicelluar tissues not only supply a very important basis in histology to determine the
基金Supported by the Geological Relic Protection Project of Ministry of Finance and Ministry of Land and Resources of China
文摘The paleoflow direction of the basal conglomerate of the Changzhougou formation is obtained by the paleocurrent analysis of certain sedimentary structures,and the ancient sedimentary environment of the Qian’an Region is determined by observing the psephicity and gradation of gravel in conglomerate.The results show that the paleoflow direction is from northwest to southwest,and the paleocurrent data manifest a single-peak style in a rose diagram.The average paleoflow direction in the Qian’an region is 265°.The basal conglomerate is of littoral facies,and the sediments of conglomerates are mainly sourced from Shanhaiguan.
