Laminacja pozioma, przekątna i konwolutna w ludlowie z wiercenia Lębork

Abstract

HORIZONTAL, CROSS AND CONVOLUTE LAMINATIONS IN THE LUDLOVIAN PIERCED BY THE BORE HOLE LĘBORK (EAST POMERANIA)SummaryThe purpose of this paper is to describe horizontal, cross and convolute laminations occurring in the Ludlovian “Siltstone Series” pierced by the Lębork bore hole at a depth of about 1720-3030 metres. None of these structures are in themselves indicative of sedimentary environment. Ludlovian deposits encountered in the Lębork bore hole are similar to those formed on tidal flats. However, no undoubtful evidence exists of their shallow water origin. The “Siltstone Series” considered was formed below wave base. The Ludlovian deposits from the area under discussion show features characteristic of turbidity current deposits. It is not out of question that the ”Siltstone Series" was formed on a submarine delta and now represents the deposits of Silurian paraliageosyncline (sensu M. Kay,1951). If that was the case the East European platform would be the main source of the sediments. On the other hand, the Ludlovian “Siltstone Series” found by the bore hole Lębork may be considered as a distal part of turbidity current deposits (laminite-sensu A. Lombard, 1963), which probably derived from the Caledonides folded along the margin of the East European platform. Due to the scarcity of data so far obtained by means of deep drillings it would be difficult to find whether siltstone material was brought from Caledonides of West Pomerania, or Denmark, i.e. whether the Silurian basin was being filled transversally or longitudinally.