Home – Home – Jornals – Russian Geology and Geophysics 2002 number 12

The Mid-Tien-Shan ophiolites make up several blocks in the Chatkal Ridge, tectonically related to the type sections of the region. The study was carried out at the most representative, Karaterek, ophiolite complex, which forms a nape lying on the Silurian volcanogenic-terrigenous deposits and Middle Carbonaceous olistostrome. The Karaterek Massif is tectonically layered and is in inverse setting. It contains (1) a complex of the melanocratic basement represented by pyroxenites, antigorite serpentinites, gabbro-amphibolites, and actinolite schists and (2) volcanogenic-sedimentary cover, whose bottom is made up of apovolcanic chlorite-epidote and other schists with members of quartz-sericite and siliceous schists. Above lie phyllites, tuff sandstones, and cherts. A complex of the conodonts Drepanoistodus sp., Paracordylodus sp., and Periodon cf. aculeatus have been documented in the cherts from the Arenigian-lower Middle Ordovician, which is the first reliable dating of the ophiolites of the region. In age and composition, the Karaterek ophiolites may, probably, be compared with the Ordovician ophiolites from the eastern Urals.