The Lower Cretaceous depositional architecture and sedimentary cyclicity in the Mid-Polish Trough

Abstract

Six depositional systems have been recognized within the Lower Cretaceous deposits of the Mid-Polish Trough basing upon borehole data (cores, well logs). These are: (1) siliciclastic shelf system (with shallow and deep silici-clastic shelf sub-systems - the latter includes anoxic shelffacies), (2) deltaic system (prograding deltas), (3) fluvial system, (4) swampy-lacustrine system, (5) lagoonal system and (6) carbonate-clastic shelf system. They have facilitated the recognition of two major sedimentary cycles – K1 and K2, which are subdivided into six minor ones of Late Berriasian through Middle Albian times. Cycle K1 begins with the Late Berriasian transgression. The beginning of cycle K2 is related to the Aptian transgression and increasing expansion of the Middle Albian basin. The Early Berriasian deposits terminate the latest Late Jurassic sedimentary cycle - J6-VII.