Naslov
Pleistocene gas-bearing clastic deposits of the Northern Adriatic, Croatia

Autori
Mikša, Goran ; Matošević, Mario ; Hernitz Kučenjak, Morana

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
36th International Meeting of Sedimentology Abstracts Book / Vlahović, Igor ; Matešić, Darko - : Hrvatsko geološko društvo, 2023, 535-535

ISBN
978-953-6907-79-3

Skup
36th International Meeting of Sedimentology

Mjesto i datum
Dubrovnik, Hrvatska, 12.06.2023. - 16.06.2023

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Gas reservoirs, Clastic deposits, Pleistocene, Northern Adriatic, Croatia

Sažetak
In the last few years, driven by high energy prices, shallow gas-bearing deposits have again become a point of interest for researchers. This refers to Pliocene and Pleistocene deposits which appear as the complex sedimentary fill of the Po Depression in the Northern Adriatic Basin. Recent works started in the area west of the Istrian coast in the Ivana gas field, provided comprehensive insight into sedimentary facies and distribution of the Pleistocene Santerno Formation. Its upper part or partly within Carola Formation consists of a frequent alternation of claystones or marls with silt layers of different thicknesses. Unlike claystones, silt layers show no signs of compaction and can be divided into very thin, 0.5–2 mm horizontally laminated layers, 5–50 mm horizontally laminated layers with common remains of vascular plants, thin-shelled bivalves and completely preserved brittle stars, and the thickest silt layers, structureless or with developed planar-cross stratification with ripples on the top, reaching a thickness 100–640 mm. Petrographic composition is relatively uniform ; homogenous claystones and marls with less amount of carbonate grains and pyrite, while the medium to coarse-grained silt is composed of quartz, feldspar, micas (muscovite, altered biotite), chlorite and carbonate grains. The Pleistocene (Calabrian) formation age is confirmed by the association of foraminifera (Neogloboquadrina pachyderma, N. incompta, Turborotalita quinqueloba, Paracassidulina neocarinata, Bulimina marginata). The depositional environment of the Santerno Formation is defined as the distal part of the Pleistocene Po River prodelta, where the silts and sands are of turbiditic origin. At the same time, the pelitic rocks represent background sedimentation from water suspension. More detailed sedimentological research revealed post- sedimentary mixing and sediment displacement processes to create a final image. The spatial distribution of silt facies with favorable permeability properties and associated pelitic seal rocks should be essential parameters for future activities planning. Data recovered from quality cored samples, together with newer seismic surveys and other advanced exploration methods, can lead to possible new hydrocarbon discoveries in the Ivana gas field and of northern Adriatic.

Izvorni jezik
Engleski

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