Coesite in eclogites of the Lanterman Range (Antarctica): Evidence from textural and Raman studies
Ghiribelli, Barbara; Frezzotti, Maria-Luce; Palmeri, Rosaria
European Journal of Mineralogy Volume 14 Number 2 (2002), p. 355 - 360
published: Mar 22, 2002
ArtNo. ESP147051402011, Price: 29.00 €
Quartz pseudomorphs after possible retrogression of coesite were recognized petrographically within garnets of mafic eclogites from the Lanterman Range (Antarctica). In one of the quartz pseudomorphs the presence of a pristine coesite is indicated by in situ Raman microprobe spectroscopy.The results of the Raman analyses show that the quartz inclusion in addition to the typical quartz vibrations has a weak band at 521 cm-1, which corresponds to the most intense fundamental vibration in coesite. This finding represents a first piece of evidence for ultrahigh-pressure metamorphism in Antarctica which was part of the Gondwana supercontinent affected by the Cambro-Ordovician orogenic cycle.