Thermal-IR emissivity investigation on lab-made silicate rocks: implications for asteroidal and planetary studies.

Kurzfassung

Silicates are the main constituent of volcanic terrains on terrestrial planets and other rocky bodies in the solar system [1]. Typically, these volcanic terrains are constituted by fragmented pyroclasts whose texture is often afanitic or porphyric rather than holocrystalline: this means that the fraction of crystalline material is less relevant than the fraction of amorphous, or glassy, material. Thus, it is of paramount importance to take into account amorphous silicate phases to explore the influence of glass/crystal ratio on the spectral response of volcanic rocks, to better interpret available and future remotely sensed spectra from past and future missions [2, 3]. Here we report the results of a study concerning mafic volcanic products which were synthesized in order to present different degrees of crystallinity: three basaltic melts were cooled at different rates to obtain different textures, from totally amorphous to crystalline. Finally, they were analysed by means of emissivity in the thermal-IR range at different temperatures.