Silicon shows no variation in its chemical valence in nature and exists mainlyin the form of silicon-oxygen tetrahedra, so very small silicon isotope thermodynamic fractionation occurs and the resultant silicon isotop...Silicon shows no variation in its chemical valence in nature and exists mainlyin the form of silicon-oxygen tetrahedra, so very small silicon isotope thermodynamic fractionation occurs and the resultant silicon isotope variation is limited. Dynamic fractionation of Si isotopes during precipitation of SiO2 from a solution is a main factor leadingto substantial variations in silicon isotopes in nature. In this experimental study, wedetermined the dynamic fractionation factor a for silicon isotopes during precipitationof SiO2 from the solution. And in combination of α, a theoretical explanation is presented of the considerably low δ30Si values of black smokers on modern seafloor, Archeanbanded magnetite-quartzite and clay minrals of weahering origin, and of clearly highδ30Si values of siliceous rocks in shallow-sea carbonate platforms.展开更多
文摘Silicon shows no variation in its chemical valence in nature and exists mainlyin the form of silicon-oxygen tetrahedra, so very small silicon isotope thermodynamic fractionation occurs and the resultant silicon isotope variation is limited. Dynamic fractionation of Si isotopes during precipitation of SiO2 from a solution is a main factor leadingto substantial variations in silicon isotopes in nature. In this experimental study, wedetermined the dynamic fractionation factor a for silicon isotopes during precipitationof SiO2 from the solution. And in combination of α, a theoretical explanation is presented of the considerably low δ30Si values of black smokers on modern seafloor, Archeanbanded magnetite-quartzite and clay minrals of weahering origin, and of clearly highδ30Si values of siliceous rocks in shallow-sea carbonate platforms.
