Blueschists discovered east of Saros Bay in Thrace.

Senturk K., Okay A.

Bulletin - Mineral Research & Exploration Institute of Turkey, pp.72-75, 1984 (Scopus) identifier


The blueschists occur as slices in a tectonic melange. The glaucophane-lawsonite schist contains prisms of pale to dark blue sodic amphiboles (0.5-0.1 mm long) and idioblastic tabular crystals of lawsonite which make up 80-90% of the rock. Anhedral sodic pyroxene, phengite and sphene are accessories. The metadolerite shows incipient metamorphism with a well-preserved relict igneous texture. Augite, yellowish-brown hornblende and minor biotite are original and 0.5-1 mm-long prismatic hornblendes are partially replaced by colourless actinolite and pale blue sodic amphibole. Augites show replacement by sodic pyroxene along veins and fractures, and along their rims. Aggregates of lawsonite, albite and chlorite have pseudomorphed primary magmatic plagioclase. Lawsonite occurs as 0.02-0.05 mm-long tabular crystals closely associated with albite and colourless aggregates of chlorite; epidote also forms large crystal aggregates. The blueschists described here are similar to those of NW Turkey, using the criteria of prograde metamorphism. The metadolerites can be compared to the lawsonite blueschists of NW Turkey, from the presence of magmatic textures, abundance of lawsonite and scarcity of sodic amphibole. -C.N.