• 责任者：Su Wenbo (School of Earth-Sciences and Resources ; China University of Geosciences ; Beijing 100083 ; China) ; Li Huaikun
• 刊名：Geological Survey and Research
• 出版年：2012
• 卷期：35(2)
• 关键词：长城纪 ; Changcheng Period ; 地层划分 ; stratigraphic classification ; 河南 ; Henan Province
• 页码：p.96-108
• 图表：6 illus., 3 tables, 89 refs.
• 分类号：1200
• issnNo：ISSN1672-4135
• isbnNo：CN12-1353/P

an lang="EN-US" style=’font-family: "Times New Roman","serif";’>By
    means of the LA-MC-ICPMS zircon U-Pb dating, an style="mso-spacerun: yes;"> an>the high-precise dates of the volcanic
    eruption, an style="mso-spacerun: yes;"> an>(1 611 ±8) Ma, an style="mso-spacerun: yes;"> an>of an interbedded tuffite layer in the middle
    part of the Luoyukou Formation at the Yangpo Section, an style="mso-spacerun: yes;"> an>Ruzhou City, an style="mso-spacerun: yes;"> an>Henan Province, an style="mso-spacerun: yes;"> an>has been obtained. With this dates, an style="mso-spacerun: yes;"> an>the depositional age of the Luoyukou Formation
    can be calibrated accurately as the first time, an style="mso-spacerun: yes;"> an>which indicates that the top age of this
    formation should be most likely about 1 600 Ma. The new dating achievement of
    the Luoyukou Formation will result in a major revision in chronostratigraphy
    that both of the two groups should be lowered down to the older Mesoproterozoic
    Changchengian System.an>