Naslov
Paleoenvironmental model for Eocene foraminiferal limestones of the Adriatic carbonate platform (Istrian peninsula)

Autori
Ćosović, Vlasta ; Drobne, Katica ; Moro, Alan

Izvornik
Facies (0172-9179) 50 (2004); 61-75

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Middle Eocene; Carbonate platform (Ramp); Microfacies; Orthophragminae; Istria
(Middle Eocene; Carbonate Platform (Ramp); Microfacies; Orthophragminae; Istria)

Sažetak
The foraminiferal limestones from the Middle Eocene Central Istrian region illustrate progressive deepening of depositional gradients. Shifting of Lower Cuisian to Upper Lutetian microfacies can be described in terms of a ramp model. The Orthophragminae-bearing parts of the foraminiferal limestones are interpreted in terms of larger foraminiferal faunal associations, planktonic foraminiferal relative abundance, limitations of algal endosymbionts, foraminiferal lamellar thicknes and flattening of test shapes. Microfacies I contains the most diverse larger foraminiferal association with a predominance of large, thick nummulitids, assilinids, and asterocyclinids. Microfacies II is characterized by a gradual increase of Orthophragminae diversity and abundance. Nummulitids, equally abundant, are dominated by lenticular and subspherical specimens. The reduction in number of nummulitid specimens with characteristic biconical radiate morphologies, and relative abundance of flattened orthophragminids, characterizes Microfacies III. Scattered biodestructed orthophragminid tests and planktonic foraminifera constitute Microfacies IV, indicating the end of a long-lasting, shallow-marine Adriatic Carbonate Platform regime.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

POVEZANOST RADA