Geologic evidence for chaotic behavior of the planets and its constraints on the third-order eustatic sequences at the end of the Late Paleozoic Ice Age
Geologic evidence for chaotic behavior of the planets and its constraints on the third-order eustatic sequences at the end of the Late Paleozoic Ice Age
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DOI：
10.1016/j.palaeo.2015.10.014
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发表时间：
2015-12
期刊：
影响因子：
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通讯作者：
Q. Fang;Huaichun Wu;L. Hinnov;X. Jing;Xunlian Wang;Q. Jiang
中科院分区：
文献类型：
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作者：
Q. Fang;Huaichun Wu;L. Hinnov;X. Jing;Xunlian Wang;Q. Jiang
对中国南部上四段厚约200m的早、中二叠世茅口组进行了高分辨率(948个样品)的磁滞剩余磁化测量。臂的变化是准周期的，有效周期的波长在整个编队中的比率为20：5：2：1，对应于长轨道偏心、短轨道偏心、倾角和进动周期。强烈的倾角(44和33 KYR)信号表明，澳大利亚东部晚古生代冰期(LPIA)末期冰盖的消融和融化对全球气候和海平面产生了重大影响。以405 KYR轨道偏心周期为天文定标目标，研制了一种天文时标(ATS)。这导致对Roadian和Wordian阶段持续时间的估计分别为3.7亿元人民币和2.9亿元人民币。突出的~2MYR旋回可能来自地球和火星的长期频率g4-g3，~1MYR旋回来自S4-S3。这些周期比新生代观察到的周期短，这可能是由于行星的混沌行为，但仍然反映了地球和火星之间的2：1长期共振。三级海平面层序与S4-S3倾角项相联系，反映了古生代冰库向中生代温室过渡阶段的冰川静力控制机制。
High-resolution (948 samples) measurements of anhysteretic remanent magnetization (ARM) were performed on the ~ 200 m thick Early–Middle Permian Maokou Formation of the Shangsi section, South China. The ARM variations are quasi-periodic and the wavelengths of significant cycles collectively present a ratio of 20:5:2:1 throughout the formation, corresponding to long orbital eccentricity, short orbital eccentricity, obliquity, and precession cycles. A strong obliquity (44 and 33 kyr) signal suggests that waning and waxing of the ice sheet in eastern Australia at the end of the Late Paleozoic Ice Age (LPIA) exerted a significant influence on global climate and sea level. A “floating” astronomical time scale (ATS) is developed using the 405 kyr orbital eccentricity cycle as an astronomical calibration target. This results in estimation of the Roadian and Wordian stages duration as 3.7 ± 0.4 myr and 2.9 ± 0.4 myr, respectively. Prominent ~ 2 myr cycles likely originated from Earth and Mars secular frequencies g4–g3, and ~ 1 myr cycles from s4–s3. These periodicities are shorter than those observed in the Cenozoic Era, which may be due to the chaotic behavior of the planets, but still reflecting 2:1 secular resonance between Earth and Mars. Third-order eustatic sequences are linked to the s4–s3obliquity term, which suggests a glacioeustatic controlling mechanism during this transitional stage from Paleozoic icehouse to Mesozoic greenhouse.