S.V. Nikolaeva, E.I.Kulagina, V.N. Pazukhin, N.N.Kotchetova & V.A. Konovalova:
Abstract.  A uniquely complete carbonate sequence spanning alarge portion of the Viséan and the entire Ser-
pukhovian is exposed on the Ural River, opposite the village of Verkhnyaya Kardailovka (South Urals,
Bashkortostan, Russia).  The Upper Visean and Serpukhovian beds in this section are composed of deep-water
carbonates containing ammonoids, conodonts, ostracodes and foraminifers.  The section is well-sampled,
measured, its lithology is now described, and a sedimentary environment near the seaward end of a carbonate
platform and deep shelf is suggested.  Abundant fossils allow the recognition of four successive ammonoid and
four successive conodont zones, which allow reliable correlations of the regional Serpukhovian stages outside
the South Urals, although the type section of thc Serpukhovian in the Moscow Basin is in the shallow-water
facies.  The base of the Serpukhovian in the Moscow Basin and in the South Urals is defined by the first ap-
pearance datum (FAD) of the conodont Lochriea ziegleri.  This level coincides with the base of the Koso-
gorskian in the Urals, correlates with the entry of the foraminifer "Millerella" tortula near the base of the Taru-
sian in the Moscow Basin and is close to the earliest occurrences of Dombatites paratectus and Cravenoceras at the
 base of the Uralopronorites-Cravenoceras Genozone and of the latter genus at the base of the British Zone E1 Zone
Because of its accessibility, abundant fossils, and its well studied lithology, the Verkhnyaya Kardailovka Section is
an exzellent candidate for the GSSP of the Vis6an-Serpukhovian boundary.