Volatile constituents in magmatic inclusions

Laser Raman microprobe has been applied to the analysis of volatile components in shrinkage gas bubbles of individual magmatic inclusions in quartz crystal fragments and phenocrystals from the Mesozoic volcanic complexes of Tonglu and Shouchang, Zhejiang Province. Quantitative analyses are given for CO₂, CH₄, H₂O, CO, H₂, N₂, H₂S, and SO₂. In conjunction with the microthermometry and microbarometry data and the chemical composition of magmatic inclusions, the results permit one to calculate the physico-chemical parametersP _total,fO ₂ ,fCO ₂ ,fCH ₄ ,fH ₂O,fCO, andfH ₂ at the time individual magmatic inclusions were trapped. Based on the data obtained, some physico-chemical conditions for the Mesozoic volcanic magma evolution in the Tonglu and Shouchang areas are discussed. This work shows that this type of studies has become an indispensable new and rising domain in modern magmatic petrology, especially modern volcanic petrology. It can help us to reconstruct the physico-chemistry of the crystallization-evolution of a natural magma. The project was financially supported by the National Science Foundation of China.