1. The Onset and Solidification Path of a Basaltic Melt by in situ Differential Scanning Calorimetry (DSC) and ex situ Investigations
- Author
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Letizia Giuliani, Gianluca Iezzi, Tyler Hippeli, Mark Davis, Aubrey Elbrecht, Francesco Vetere, Manuela Nazzari, and Silvio Mollo
- Subjects
basalt ,in situ crystallization ,Materials science ,010504 meteorology & atmospheric sciences ,Nucleation ,Analytical chemistry ,TTT diagram ,Crystal growth ,010502 geochemistry & geophysics ,Basalt ,DSC ,In situ crystallization ,Texture ,01 natural sciences ,law.invention ,Crystal ,Differential scanning calorimetry ,Isothermal transformation diagram ,law ,General Earth and Planetary Sciences ,lcsh:Q ,Texture (crystalline) ,Crystallization ,lcsh:Science ,Glass transition ,texture ,0105 earth and related environmental sciences - Abstract
The in situ differential scanning calorimetry (DSC) technique has been applied to investigate the solidification paths of a basaltic liquid. The starting glass was heated up to 1300°C, kept at this superliquidus temperature for 2 h and cooled at rates (ΔT/Δt) of 7, 60, 180, 1000, and 1800°C/h, down to 800 and 600°C. Glass transition temperature (Tg), crystallization temperature (Tx_HR) and melting temperature (Tm) were measured by in situ DSC spectra on heating. Tx measured along the cooling paths (Tx_CR) shows exothermic peaks that change from a single symmetric shape (7 and 60°C/h) to multi-component patterns (180, 1000, and 1800°C/h). The recovered products characterized by field emission gun source of the scanning electron microscopy and electron probe micro-analyzer-wavelength dispersive spectrometers show a phase assemblage of spinel (sp), clinopyroxene (cpx), melilite (mel), plagioclase (plg), and glass. Moreover, crystal size distributions (CSDs) and growth rates (Gmax and GCSD) were also determined. The crystal content slightly increases from 7 to 1800°C/h. Faceted sp are present in all the run products with an amount always
- Published
- 2020