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
Mounting evidence indicates that the orbital period of the solar system’s movement through the Milky Way has had a controlling effect on processes of the Earth’s system throughout the Phanerozoic.To decipher the res...Mounting evidence indicates that the orbital period of the solar system’s movement through the Milky Way has had a controlling effect on processes of the Earth’s system throughout the Phanerozoic.To decipher the response of a given terrestrial basin’s rhythms to galactic dynamics,for the first time,we report long-term cycles recorded in the Mesozoic Ordos Basin(Central China).The astronomical time scale(ATS)was established for each successive sedimentary sequence,and the duration of unconformity episodes was estimated based on the chronological constraints.Using this timescale,time-series analysis of the deposition rate is carried out through the Mesozoic Ordos Basin,which reveals compelling periodicities of 93,33,9,3-5,and 2.4Myr.The radial solar system motions around the galactic centre and plate tectonic cycles act cooperatively to impact the magmatic tempo of the Qinling orogenic belt and the 93-Myr depositional cycle of the Mesozoic Ordos Basin.The Mesozoic 33-Myr cycle is a sedimentary response to the half-period of the solar system’s vertical oscillation about the galactic plane.A rational explanation is that galactic oscillation affects mantle convection,which is responsible for periodic asthenospheric upwelling and ultimately controls the vertical crust oscillation of the Ordos Basin.Mesozoic 9-Myr and the higher-frequency 3-5and 2.4-Myr depositional cycles can be sedimentary responses to the Earth’s orbital eccentricity,which affected the temporal variation in depositional environments in the Ordos Basin.Apart from the galactic-geologic correlations,long-term cycles recorded within a sedimentary basin should also consider the tectonically driven mechanisms at these timescales.This framework provides a new perspective for revealing the astronomical origin of Earth’s rhythms.展开更多
文摘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.
基金supported by the National Natural Science Foundation of China(Grant Nos.42102166,42090025,and 41625009)。
文摘Mounting evidence indicates that the orbital period of the solar system’s movement through the Milky Way has had a controlling effect on processes of the Earth’s system throughout the Phanerozoic.To decipher the response of a given terrestrial basin’s rhythms to galactic dynamics,for the first time,we report long-term cycles recorded in the Mesozoic Ordos Basin(Central China).The astronomical time scale(ATS)was established for each successive sedimentary sequence,and the duration of unconformity episodes was estimated based on the chronological constraints.Using this timescale,time-series analysis of the deposition rate is carried out through the Mesozoic Ordos Basin,which reveals compelling periodicities of 93,33,9,3-5,and 2.4Myr.The radial solar system motions around the galactic centre and plate tectonic cycles act cooperatively to impact the magmatic tempo of the Qinling orogenic belt and the 93-Myr depositional cycle of the Mesozoic Ordos Basin.The Mesozoic 33-Myr cycle is a sedimentary response to the half-period of the solar system’s vertical oscillation about the galactic plane.A rational explanation is that galactic oscillation affects mantle convection,which is responsible for periodic asthenospheric upwelling and ultimately controls the vertical crust oscillation of the Ordos Basin.Mesozoic 9-Myr and the higher-frequency 3-5and 2.4-Myr depositional cycles can be sedimentary responses to the Earth’s orbital eccentricity,which affected the temporal variation in depositional environments in the Ordos Basin.Apart from the galactic-geologic correlations,long-term cycles recorded within a sedimentary basin should also consider the tectonically driven mechanisms at these timescales.This framework provides a new perspective for revealing the astronomical origin of Earth’s rhythms.
