Palaeotectonic evolution of the Baltic Syneclise during the Early Palaeozoic as documented by palaeothickness maps

Abstract

Analysis of palaeothickness maps of the uppermost Vendian-Lower Cambrian and Middle Cambrian of the Baltic Syneclise has shown that thickness variability of those sediments was controlled by subsidence differentiation and palaeorelief of the buried crystalline basement. During the Late Cambrian-Tremadoc uplifting movements dominated with the exception of the westernmost part of the Baltic Syneclise which was undergoing subsidence. During the Ordovician the Jelgava Depression was the most prominent palaeotectonic element. It embraced the northeastern part of the analysed area. Since the Early Silurian times a distinct subsidence increase had taken place. During the Early Silurian this phenomenon was restricted to the peripheral part of the Pre-Vendian Platform. Later, on in the Late Silurian times this process embraced the whole analysed area.