Discussion of the paper by Vincent et al., 2018, entitled 'Age constraints on intra-formational unconformities in Upper Jurassic-Lower Cretaceous carbonates in northeast Turkey; geodynamic and hydrocarbon implications' (Marine and Petroleum Geology, 91, 639–657)

A recent publication on the Jurassic-Cretaceous transition in carbonate platforms of NE Turkey reported some major discontinuities. Based on biostratigraphy and Sr-derived ages, one associated hiatus was estimated spanning the Tithonian whereas the remaining three minor hiatuses are supposed to have occurred during the Hauterivian - Barremian interval. The revision of the material (foraminifers and calcareous algae) from the 2 localities studied led to identify Kimmeridgian strata below the discontinuity and Valanginian to ? lower Hauterivian strata above the discontinuity, but no upper Hauterivian or Barremian strata at the top of the section. The major stratigraphic gap possibly corresponds to the Berriasian and most, if not all, of the Tithonian at this location.