Discussion of the paper by Imad M. Ghafor and Ibrahim MJ Mohialdeen, 2018, entitled 'Early cretaceous microfossils associations (foraminifera, ostracoda, calcareous algae, and coral) from the Garagu formation, Duhok area, Kurdistan region, northern Iraq' (Arabian Journal of Geosciences, 11:407)

摘要

A recent "micropaleontological" publication on a Lower Cretaceous classical lithostratigraphic unit at its type locality in N Iraq, the Garagu Formation, suggested that, at this exact location, this facies-driven unit could span a "late Valanginian-Barremian" time interval and that its facies were indicative of "shallow marine with normal to hypersaline conditions, shelf lagoonal environment, and open platform" environment. Of the twenty samples originally collected by the authors, eleven thin sections were reexamined. On the basis of this limited material, a second assessment is presented here. Most micropaleontological identifications prove wrong, and they cannot "support an age determination of the late Valanginian-Barremian". Similarly, contrary to the authors' opinion and except for one sample, all microfacies suggest that the sedimentary depositional environments were representative of a lower shoreface to an offshore shelf setting depending on relative sea level changes. More than half a century after the publication of the "Lexique International de Stratigraphie", the Garagu Formation, as do most lithostratigraphic units defined in the Middle East, requires a full reassessment with the support of genuine experts.