An Early Carboniferous conodont fauna was recovered and evaluated throughhout a
 section consisting predominantly of carbonates of the Ermita and the Alba forrnations in
 the Esla area of the Cantabrian Mountains.  The sedimentary contact of these units is a
 discontinuity surface marked by an abrupt color change from grey to red, The data
 published until now both on stratigraphy and on the nature of the contact surface are
 controversial.
    Conodont fauna collected below and above the discontinuity surface is
 stratigraphically admixed due to reworkin of older (Tournaisian and Devonian) conodont
 elements.  The strati.-raphic analysis has revealed the prescnce of a hiatus between the
 Ermita and Alba formations, comprising the late Tournaisian anchoralis Zone.  The
 topmost part of the Ermita Formation has been attributed to the cuneiformis Zone
 (Tournaisian).  The base of the Alba Formation has been definitely dated as texanus Zone
 of early Viéan age.  The stratigraphic potential of Gnatodus praebilineatus in. the
 subdivision of the early Viséan is indicated.