Depositional environment and petrology of Rotliegend deposits from the Unisław - Wałdowo Królewskie region
¦rodowisko depozycji i petrologia utworów czerwonego sp±gowca w rejonie
Unisław - Wałdowo Królewskie
ARKADIUSZ BUNIAK, ZBIGNIEW MIKOŁAJEWSJKI, ALEKSANDER PROTAS
Geological Bureau - GEONAFTA Warszawa, Regional Division Piła,
Abstract: The Rotliegend deposits have been drilled in the following boreholes: Unisław 2, Unisław 4, Unisław IG1, Unisław IG2 and Wałdowo Królewskie 1. In studied area these sediments constitue a differentiated lithological complex, being a product of varied depositional conditions, controlled mainly by tectonic and paleoclimatic factors. Two general facies associations: lacustrine and fluvial ones have been distinguished. Lacustrine facies is dominated by claystones, siltstones and fine sandstones originated in seasonally dried lake and fluvial sediments are represented by varigrained sandstones accumulated as channel and sheetflood deposits. Two phases of Rotliegend deposition were defined: the first one of a fluvial character and the second one of a lacustrine type. Evolution of porosity was controlled by cementation processes and low reservoir properties of lacustrine deposits are a consequence of high finegrained matrix content. Fluvial sediments are considered as a potential reservoir rock complex.
Key words: Rotliegend, facies analysis, diagenesis, reservoir properties, Koszalin-Chojnice-Toruń zone
