5:45 PM - 6:00 PM
[MTT44-09] Molecular Geochemistry as a Future Topic in Geochemistry
Keywords:Molecular Geochemistry, Goldschmidt
However, his discussion on the distribution of these elements on the basis of the properties of their atoms and ions could not be proved by any methods, since it was difficult at that time to clarify the chemical species (bonding nature and structure) of trace elements. At present, on the other hand, we can determine the neighboring atom and interatomic distance of trace elements in various samples by advanced speciation methods such as by X-ray absorption fine structure (XAFS) spectroscopy. As shown in our recent studies, abundances and isotopic compositions of various elements in natural samples strongly depend on the chemical state of various elements in nature. This fact shows that we can predict behaviors and isotopic fractionation of various elements based on physic-chemical properties. This field can be called as "Molecular Geochemistry". This field includes (i) identification of organic polymolecules in nature which can be used for the paleoenvironment reconstruction, (ii) isotopomers of various molecules, and (iii) fundamental understanding of isotopic fractionation such as mass-independent fractioation. Thus, I propose "Molecular Geochemistry" as an important future topic of geochemistry, which cannot be conducted by researchers in other fields in earth and planetary sciences and must be conducted by Prof. Goldschmidt if he could use the methods to reveal the atomic- and molecular-level information in geochemical samples.