Chemical Weathering during the Neoproterozoic Snowball Earth Events
Chen Xinyang
Li Biao
Li Chao
Abstract：Two global-scale Snowball Earth events occurred during the Cryogenian period of the Neoproterozoic era(ca.720‒635 Ma),representing a crucial transition period for the Earth's biological systems and environmental evolution.An increasing amount of evidence indicates that there are spatio-temporal fluctuations in the climate and marine redox state during the Snowball glaciation.However,the driving mechanisms of the carbon cycle-land-ocean system interaction and glacial climate fluctuations during this period remain largely unclear.Continental weathering is a key process linking snowball development,ocean chemistry,and biological evolution,but existing research has been unable to effectively characterize continental weathering during the Snowball period.This paper summarizes the current status of proxies for chemical weathering intensity during the Cryogenian period,and statistically analyzes the major-element data of 867 clastic rock samples from 28 Cryogenian sections(including drill cores)worldwide.Using the index of ln(Al2O3/Na2O),the evolutionary trend of the global average chemical weathering intensity from the Late Tonian period to the Early Ediacaran period is quantitatively reconstructed.Three fluctuations in chemical weathering intensity are discovered,indicating that the onset and termination of glaciation are closely related to chemical weathering.In addition,the average weathering intensity during the Marinoan glaciation is significantly higher than that during the Sturtian glaciation,possibly suggesting the existence of a certain degree of hydrological circulation during the Marinoan glaciation.Future research can further apply the comprehensive application of multiple proxies to deepen the understanding of the chemical weathering mechanisms during the Cryogenian period,and provide more in-depth perspectives and evidence to support the exploration of global environmental evolution.
Keywords：NeoproterozoicCryogenianchemical weathering intensitySnowball Earthcarbon cycleclimate change
Publication Date：2025-03-14
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：18( 1048-1065 )