Rozwój badań i poszukiwań geologicznych między Szczecinem a Koszalinem w latach 1955-1983

Ryszard Dadlez, Stanisław Tyski



The former meeting of the Polish Geological Society in the Szczecin region has taken place in 1955. It was mainly devoted to geology of the Quaternary as knowledge of Quaternary basement was rather limited at that time. Twenty eight years which have passed since that time witnessed marked progress in knowledge of geological structure, especially deep structure of this region. This was due to seismic surveys comprising reflection seismic profiles several thousand kilometers long, and over a hundred of deep (up to 3.0-4.5 km deep) drillings.
The studies also resulted in some economic successes - discoveries of hydrocarbon accumulations. The studies and prospecting have been mainly carried out by the Geological Institute of Warsaw and the Piła, Toruń and Warsaw branches of the oil industry. The studies carried out by the Geological Institute have been initiated in the years 1954-1957 by making a series of shallow (300-500 m deep) drillings, aimed at mapping basement of the Quaternary. The drillings, making possible studies on partial sections of Jurassic and Cretaceous rocks which form basement of the Quaternary in this region, were made along profiles oriented normally to the strike of uplifted tectonic unit - the Pomeranian Swell. They were supplemented by a single deeper (1300 m deep) drilling which penetrated the whole section of Lower Jurassic strata. The studies resulted in discovery and proving two deposits of clay ironstones .of limited economic value in the Bajocian.
The second stage in field carried out by the Geological Institute (years 1962-1968) was aimed at search for hydrocarbons in the Zechstein in connection with discoveries of oil in rocks of that age in northern GDR and Fore-Sudetic region in Poland. The studies involved compilation of seismic maps and making over a dozen deep drillings which made possible reconstruction of typical sections of the Mesozoic and Permian, tracing major features of geological structure of this complex and gathering preliminary data on pre-Permian rocks in this area. Some drillings revealed marked traces of oil in carbonate Zechstein horizons. The records of such traces and new discoveries of oil deposits in neighboring parts of the GDR were the direct reason of initiation of intense prospecting programmes by the oil industry (years 1969-1983) which, on a limited scale, took part in the studies at their earlier stage. A systematic seismic survey, involving analog and, subsequently, numerical recording, began at that time. They were followed by numerous deep drillings, at first aimed at the Zechstein and Rotliegendes. The prospecting resulted in discovery of some deposits of nitrogen-rich gas and in 1972 - oil deposit at Kamień Pomorski, the richest of the hitherto found in the Polish Lowlands. Along with time, the range of studies was extended to cover basement of the Permian. This resulted in discovery of two gas deposits in Upper Carboniferous! sandstones in the mid-seventies. At the same time, a marked progress in the knowledge of stratigraphy and tectonics of the Zechstein - Mesozoic complex has been made and typical sections of the Devonian-Carboniferous complex were reconstructed.

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