The eastern taurus mountains of Turkey lie on a plate boundary where two areas of continental lithosphere are converging (McKenzie 1970), and there is large-scale thrusting (Ilhan 1971) comparable with that of the Himalayas (Gansser 1964), another region of continental collision.
In the central Taurus there is an extensive tract of greenschist to amphibolite facies metamorphic rocks, the 'Bitlis Massif' (Fig. I). Palaeontological evidence (Altinli 1966) and geochronological evidence (Yilmaz 1971)1 suggest that these rocks were deposited, deformed and metamorphosed in Palaeozoic times. The earlier suggestion that the Bitlis Massif is metamorphosed Mesozoic sediments (Rigo de Righi & Cortesini 1964) can be ruled out in the light of more recent published work. The southern boundary of the Bitlis Massif is tectonic; the metamorphic rocks being thrust over a complex of wildflysch and ophiolites which often has the characteristics of a mélange, as defined by Hsfi (1968). This ophiolite-flysch complex is also thrust over Tertiary and Mesozoic rocks on the northern edge of the Syrian platform. The ophiolite-flysch belt has been regarded as a Tethyan suture (Smith 1971) and the Bitlis Massif as the crystalline basement of the over-riding Anatolian Plate (Peyve 1969).
An expedition in 1971 found serpentinite-rich mélange well inside the Bitlis Massif. Near the village of Mutki, 27 km west of Bitlis, there is a strip of mélange, 1–3 km wide, trending roughly E–W and fanked by metamorphic rocks to the north and the south. The metamorphic rocks are phyllites, quartzitic phyllites, quartzites and marbles, showing evidence of