Zmienność facjalna warstw lgockich (alb) w okolicy Wadowic

Abstract

Facies change of the Lgota Beds (Albian) in the Wadowice area (Western Carpathians) East of Wadowice the Sub-Silesian and Silesian nappes are folded together into a complex anticlinal structure, called the Lanckorona zone. In this zone the Sub-Silesian nappe occurs in a few small tectonic windows, while the flanks of the zone are formed of beds belonging to the Silesian nappe (Fig. 1, 3, 4). In the northern flank of the zone the Silesian nappe contains the typical Lgota Beds, developed mainly as dark, well laminated sandstones alternating with black shales. In the southern limb there occur glauconitic coarse sandstones with poorly marked lamination and grey-green spotted shales. Their stratigraphie position, so far uncertain, has been cleared owing to microfaunal research. These beds, provisionally called Barwałd Beds, contain foraminiferal assemblages identical with those of the Lgota Beds (see tables 1 and 2). In some places they are covered by variegated, mainly red, shales with a microfauna corresponding with that of the Variegated Godula Shales (Cenomanian-Turonian, see table 3, columns 2—4). In normal cross-sections the Barwałd Beds are underlain by the Barremian- Aptian Verovice Shales. The Albian of the Sub-Silesian nappe occurring in the windows is developed either as the Gaize Beds (spiculitic sandstones, spongiolites and shales, Fig. 1, 4), or as grey-green spotted shales (Fig. 3). Either facies contain microfaunas identical with that of the Lgota Beds (see the list page 36 for the shales, and the list page 33 for the Gaize Beds). According to the spatial distribution of these four facies of the Albian one can reconstruct their position in the flysch basin. The Gaize Beds occupied the most northern zone; more to the south only shales were deposited, bordered from the south by the typical Lgota Beds, while the Barwałd Beds occupied an innermost position. Compared with the Lgota Beds, which exhibit a well pronounced lamination and not rare small-scale current bedding, the Barwałd Beds may be regarded as a more proximal deposit. Their material, similarly as that of the Lgota Beds, was brought in from the south or south-west, while that of the Gaize Beds was transported from the north and north-west.