Naslov
Upper Miocene sedimentary rocks along the Northern marginal fault of the Sava depression influenced by syn-sedimentary tectonics (Kloštar oil field, Pannonian basin, Croatia)

Autori
Velić, Josipa ; Malvić, Tomislav ; Cvetković, Marko ; Jović, Goran

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

Izvornik
Tectonics & Sedimentation (conference volume) / Tom McCann, Niko Froitzheim, Jean Thein, Andreas Schafer - Bon : University of Bonn, Steinmann Institute - Geology, 2009, 77-77

Skup
Tectonic and Sedimentation

Mjesto i datum
Bonn, Njemačka, 16.02.2009. - 18.02.2009

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Upper Miocene; palinspastic; Sava depression; Kloštar field

Sažetak
The Kloštar field is located approx. 35 km east of Zagreb. The oil production started in the 1954. The field is situated in the Sava Depression, i.e. near the SW margin of the Pannonian Basin. The Miocene deposits (up to 1600 m thick) are transgressive over Palaeozoic magmatites and metamorphites. Upper Miocene deposits are up to 1200 m thick (Pannonian and Pontian ages, the 2nd Neogene megacycle [1]). Oil reservoirs are placed within Miocene sandstones and tectonized Palaeozoic basement. The field structure is composed of an anticline striking NW-SE, faulted by transversal and longitudinal (strike-slip) faults. The main longitudinal fault crosses the central part of the field, representing the continuation of the Northern marginal fault of the Sava Depression [2], [3]. This fault changes the character along the strike (normal fault on the north and reverse on the south). The vertical displacements determined according to the boundaries of stratigraphic units (determined via e-markers) are up to 50 m. The cumulative displacement during the Late Miocene was circa 150 m [2]. The rate of vertical tectonic displacements was increased in the younger sediments, and the maximum was in Late Pontian. The Upper Miocene deposits, especially of Pannonian age, are mostly turbidite deposits [4], represented by calcitic marlstones, fine-grained sandstones and soft sandy clays. Depositional model indicates change of predominant material sources – from local (Moslavačka Mt., distance of few km) to very distant (the Alps, several hundred km away). Variable transportation energy resulted in often and significant changes of margins and depths of depositional areas. This was caused by the Northern marginal fault and by the transversal fault striking NE– SW across the entire depression [2], [5]. Palinological analyses of Pannonian age samples indicated on lacustric environment, but also on significant influence from the land, i.e. material that originated from marshes, plains and moderately high mountains. Land-derived material had been transported during the period of warm, humid climate [5]. Lower Pannonian depositional environment was mostly shallow, composed of smaller, isolated lakes. Upper Pannonian reservoir sandstones have been deposited only in the western part of the field, in brackish to fresh-water environment. In the latest Pannonian the shoreline had been reduced toward uttermost southwest. During Pontian sedimentation has been active over the entire structure, as evidenced by faster sinking of the hanging wall of the Northern marginal fault. References [1]VELIĆ, J., WEISSER, M., SAFTIĆ, B., VRBANAC, B. & IVKOVIĆ, Ž. (2002): Petroleum-geological characteristics and exploration level of the three Neogene depositional magacycles in the Croatian part of the Pannonian basin. – Nafta, 53 (6-7), 239-249, Zagreb. [2]VELIĆ, J. (1983): The neotectonic relations and development of the western part of the Sava river depression. Acta Geol. JAZU, 13/2, 26-65. [3]PRELOGOVIĆ, E., SAFTIĆ, B., KUK, V., VELIĆ, J., DRAGAŠ, M. & LUČIĆ, D. (1998): Tectonic activity in the Croatian part of the Pannonian basin. Tectonophysics, 297, 1-4, 283-293. [4]VRBANAC, B., VELIĆ, J. & MALVIĆ, T. (2008): Sedimentation of Late Pannonian clastic deposits in main and marginal basins (Sava depression vs. Bjelovar subdepression). Geophysical Research Abstracts, Vol. 10, Copernicus Group, 1-2, Vienna. [5]LUČIĆ, D., SAFTIĆ, B., KRIZMANIĆ, K., PRELOGOVIĆ, E., BRITVIĆ, V., MESIĆ, I., & TADEJ, J. (2001): The neogene evolution and hydrocarbon potential of the Pannonian Basin in Croatia. Marine and Petroleum Geology, 18, 1, 137-147.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

Napomena
Predavanje je održao Marko Cvetković.

POVEZANOST RADA