Sarmatian paleoecological environment of the Machów Formation based on the quantitative nannofossil analysis — a case study from the Sokołów area (Polish Carpathian Foredeep)The Machów Formation belongs to a supra-evaporitic succession of the Polish Carpathian Foredeep Basin (PCFB). Our studies were concentrated in the eastern part of the PCFB, north of Rzeszów. 33 samples were collected from five boreholes, at depth intervals as follows: Stobierna 2 — 1016-1338 m; Stobierna 3 — 715-1669 m; Stobierna 4 — 1016-1238 m; Stadnicka Brzóza 1 — 350-356 m and 1043-1667 m; Pogwizdów 2 — 1161-1390 m. The obtained biostratigraphical data gave evidence for the upper part of the NN6 (the Early Sarmatian) and for the NN7 (the lowermost part of the Late Sarmatian) Zones. All the nannofossil assemblages from Stobierna 2, Stobierna 4 and Pogwizdów 2 were assigned to the NN6 Zone. In the Stobierna 3 borehole the interval 1669-1113 m was assigned to NN6, whereas assemblages from depth interval 843-715 m belong to NN7 Zone. In Stadnicka Brzóza 1 interval 1667-1043 m belongs to NN6 Zone and interval 350-356 m to NN7 Zone. TheDiscoaster exilisZone (NN6) was defined by the presence ofReticulofenestra pseudoumbilica,Sphenolithus abies,Helicosphaera walbersdorfensisand absence ofDiscoaster kugleri.TheDiscoaster kugleriZone (NN7) assignment was based on the abundance ofCoccolithus miopelagicus(> 10 μm), used as an alternative species essentially confined to that interval, and absence ofCatinaster coalithus.The observed nannoplankton assemblages are predominantly composed of a high number of redeposited material, abundant long-ranging taxa and taxa resistant to carbonate dissolution. General assemblage compositions, obtained from quantitative data, indicate shallow near-shore environment and could confirm basin isolation.
Estimating the Age of Near-Shore Carbonate Slides Using Coral Reefs and Erosional Markers: A Case Study from Curacao, Netherlands Antilles
