【摘 要】
：
The studies on stromatolites occurring in the Mesoproterozoic Tieling Formation, Zhoukoudian, Beijing indicate that the thickness of bright-dark lamina pairs in
【机 构】
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Faculty of Earth Sciences,Nanjing Institute of Geology and Paleontology
【基金项目】
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中国地质大学校科研和教改项目;国家自然科学基金
论文部分内容阅读
The studies on stromatolites occurring in the Mesoproterozoic Tieling Formation, Zhoukoudian, Beijing indicate that the thickness of bright-dark lamina pairs in the stromatolites shows periodic variations, which are interpreted as monthly and seasonal rhythms. On the basis of the S-shaped stromatolites, some preliminary paleo-astronomic parameters have been obtained as follows: In the late Mesoproterozoic (1000 Ma ago) there were at least 516±20 d, 12.9±0.5 months per year, 40 d per month and at most 16.99±0.66 h per day, and paleo-obliquity of the ecliptic was 29.2°- 30.6°.
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