Sedimentary and Diagenetic Controls across the Cretaceous—Paleogene Transition: New Paleoenvironmental Insights of the External Ionian Zone from the Pelagic Carbonates of the Gardiki Section (Epirus, Western Greece)

Field investigation, biostratigraphic, paleoecological, and sedimentary microfacies analyses, as well diagenetic processes characterization, were carried out in the Epirus region (Western Ionian Basin) to define depositional environments further decipher history of Late Cretaceous–Early Paleocene carbonate succession western continental Greece. Planktonic foraminiferal biostratigraphy studied carbonates revealed that investigated part Gardiki section covers Cretaceous–Paleogene (K-Pg) transition, partly reflecting Senonian limestone calciturbidites formations zone stratigraphy. Litho-and bio-facies analyses allowed for recognition three distinct facies: (a) latest Maastrichtian pelagic biomicrite mudstone with situ planktonic foraminifera, radiolarians, filaments, (b) a packstone abundant foraminifera at K-Pg boundary, (c) an early wackestone veins, micritized mixed fauna terms reworked (aberrant or broken) foraminifera. The documented facies characterize relatively low medium energy deep environment, representing transition from basin shelf toe slope crossing boundary. Micropaleontological paleoecological samples demonstrate primary productivity collapse is key proximate cause this extinction event. Additional petrographic showed petrophysical behavior reservoir characteristics study deposits are controlled by environment (marine, meteoric, burial diagenetic) influenced such micritization, compaction, cementation, dissolution, fracturing.