Stratigraphy and microfacies of the Jurassic and lowermost Cretaceous of the Veliky Kamenets section (Pieniny Klippen Belt, Carpathians, Western Ukraine)

The Veliky Kamenets section in the eastern part of the Pieniny Klippen Belt in the Ukrainian Carpathians shows a well exposed, 83 m thick succession composed of Jurassic and lowermost Cretaceous (Berriasian) deposits. The terrigenous part of the section includes: gravels with a sandy matrix (unit 1A), massive grey-green sandstones (unit 1B) and shales with intercalations of siltstones/sandstones and oyster/gastropod lumachelles (unit 2). Organic-walled dinoflagellates document the Toarcian-Aalenian age of the siliciclastic deposits of unit 2. The carbonate part of the succession embraces: stromatactis mud-mounds interfingering with crinoidal limestones (unit 3A), lower nodular limestones (unit 3B), cherty limestones (unit 3C), upper nodular limestones (unit 3D), pink pelitic limestones (unit 3E), limestones with a volcanogenic bed (unit 5) and limestone breccia limestones (unit 6). This succession has yielded abundant ammonites from the Bathonian, Oxfordian and Kimmeridgian (with a stratigraphical hiatus covering the Callovian and Lower Oxfordian), as well as calcareous dinoflagellates (from the Upper Oxfordian towards the top of the succession), and calpionellids (in the Tithonian and Berriasian). Detailed stratigraphical study of the succession based both on ammonites and microfossils has resulted in the recognition of biostratigraphical units and their correlation with the chronostratigraphical scale.The microfacies recognized in the pelagic part of the succession include: the “filament” (Bositra) microfacies (Bathonian), the planktonic foraminifer microfacies (Oxfordian), the Saccocoma microfacies (Kimmeridgian to Upper Tithonian), and the calpionellid microfacies (Upper Tithonian–Berriasian). The volcanogenic rocks (lava flows and volcanic ash) appear in the topmost part of the succession (units 4 to 6) and this volcanic event is very precisely located in the Elliptica-Simplex chrons of the Middle and Late Berriasian.