Siluro-Devonian (Pridoli-Lochkovian and early Emsian) conodonts from the Nowshera area, Pakistan: implications for the mid-Palaeozoic stratigraphy of the Peshawar Basin

The Kandar Formation (junior synonym, Panjpir Formation) spans most of Silurian time from Llandovery-Wenlock to Pridoli, with its youngest horizons, documented by conodonts, falling within the Pridoli eosteinhornensis Zone. Portion of the conformably overlying (but perhaps locally unconformable) Nowshera Limestone of the Nowshera-Pir Sabak area falls within the eosteinhornensis Zone, but the bulk of this unit is inferred to extend from Early Devonian (Lochkovian) near Kandar through to dehiscens Zone (early Emsian) in the highest beds exposed at Pir Sabak. The question of which, if any, of the intervening zones may be represented needs clarification. Regional considerations suggest that Silurian-Devonian sequences around the eastern flank of the Peshawar Basin may display a conspicuous transgressive event within the Middle Devonian. This needs to be probed. It is suggested therefore that caution should be exercised before late Emsian and younger sequences around the Peshawar Basin are referred to the Nowshera Limestone-at least until additional stratigraphic-cum-sedimentary and chronologic data demonstrate continuity of sedimentation through the Middle Devonian for these sequences. From the Nowshera Limestone, a new subspecies of Ozarkodina remscheidensis, O. r. prosoplatys, is described. It is proposed that the new subspecies is an intermediate between O. r. eosteinhornensis and the Ancyrodelloides (= Lanea sensu MURPHY and VALENZUELOS-RIOS 1999) lineage.