LYMBADA FORMATION OF THE UPPER DEVONIAN OF THE NORTHERN PAY-KHOY CARBONATE PARAUTOCHTONE: NEW DATA
The new data on the composition and age of the Lymbada Formation (D3 C1 lb ) of the Pay Khoy carbonate parautochtone are considered. The formation is composed of shoaly carbonate deposits containing cherty concretions and abundant benthic fossils. Conodont and stromatoporoid data suggest correlation of the middle part of the formation with marginifera Lower expansa conodont zones (Famennian), and correlation of the upper part of the formation with duplicata isosticha conodont zones (Tournaisian). Famennian conodont associations are abundant ( Hindeodus albus , Mitrellataxis circularis , and Pol. semicostatus among others) and include some specific forms ( Polygnathus aff. delenitor , Pol. aff. experplexus , Pol . sp. A, and Pol . sp. B). Rare Tournaisian conodonts represented by Polygnathus longiposticus and Plukidina sp. occur in the uppermost part of the Lymbada Formation. The late Tournaisian age of the upper part of the Lymbada Formation isproved by the isotope (δ13Ccarb) stratigraphy. Thestudied deposits contain remains of the Famennian stromatoporoids. The stromatoporoids are represented by Labechia, Actinostroma, Anostylostroma, Trupetostroma, and Amphipora. The disconformity corresponding to the upper Tournaisian lower Visean is supposed at the upper boundary of the Lymbada Formation.