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Reconciling the Earth’s stratigraphic record with the structure of our galaxy
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作者 Michael Gillman Hilary Erenler 《Geoscience Frontiers》 SCIE CAS CSCD 2019年第6期2147-2151,共5页
The passage of our Solar System through the spiral arms has been implicated as a contributor to global environmental perturbations.The suggestion of a consistent structure within the arms,informed by density wave theo... The passage of our Solar System through the spiral arms has been implicated as a contributor to global environmental perturbations.The suggestion of a consistent structure within the arms,informed by density wave theory,raises the possibility of repeating patterns of events at each arm crossing.Here we test the hypothesis that the structure of the arms of our galaxy influences the stratigraphic record on Earth.We construct independent structural and temporal models and colbine these to compare the timings of arm tracers,materials from the earliest Solar System and events on Earth,including the largest extinctions.We find that a recurring sequence of events across the four arms emerges with an average arm-passing time of 188 million years.We suggest that the multiple temporal overlaps of events across arms,and their alignment with arm tracers and the earliest Solar System,presents an opportunity for a greater understanding of both Earth-based phenomena and galactic structure. 展开更多
关键词 SPIRAL ARMS STRATIGRAPHY Superchron Earliest Solar System EXTINCTIONS GLACIATIONS
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Nonlinear Dynamic Study on Geomagnetic Polarity Reversal and Cretaceous Normal Superchron
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作者 SHEN Wei 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2007年第6期1097-1102,共6页
It is generally acknowledged that geomagnetic polarity has reversed many times in geological history and an abnormal geologic phenomenon is the Cretaceous normal superchron. However, the causes have been unknown up to... It is generally acknowledged that geomagnetic polarity has reversed many times in geological history and an abnormal geologic phenomenon is the Cretaceous normal superchron. However, the causes have been unknown up to now. The nonlinear theory has been applied to analyze the phenomenon in geomagnetic polarity reversal and the Cretaceous normal superchron. The Cretaceous normal superchron implies that interaction of the Earth's core-mantle and liquid movement in the outer core may be the lowest energy state and the system of Earth magnetic field maintains a sort of temporal or spatial order structure by exchanging substance and energy in the outside continuously. During 121-83 Ma, there was no impact of a celestial body that would result in a geomagnetic polarity reversal, which may be a cause for occurrence of the Cretaceous normal superchron.The randomness of geomagnetic polarity reversal has the self-reversion characteristic of chaos and the chaos theory gives a simple and clear explanation for the dynamic cause of the geomagnetic polarity reversal. 展开更多
关键词 NONLINEARITY geomagnetic polarity reversal Cretaceous normal superchron (CNS)
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