Physicochemical or geochemical

• Reich, M., Zúñiga, A., Amigo, Á., Vargas, G., Morata, D., Palacios, C., Ángel Parada, M., Garreaud, R. D. , (2009), Formation of cristobalite nanofibers during explosive volcanic eruptions, Geology, 37(5), 435-438, 10.1130/G25457A.1