Palinspastic reconstruction of Permo-Carboniferous basins involved in Alpine deformation: the Erill Castell-Estac basin, Southern Pyrenees, Spain

Abstract

Permo-Carboniferous rocks are located in the lower thrust sheets of the Alpine antiformal stack in the Central Pyrenees. In order to study the geometry, distribution of facies, thickness and dynamics of Permo-Carboniferous basins, a detailed knowledge of Alpine tectonics is required, which has not always been taken into account by previous authors. This paper follows a different approach to the study of these basins. The Alpine structural units bounding the Permo-Carboniferous series of the eastern part of the Erill Castell-Estac basin have been mapped in detail, as a first step in this palinspastic restoration. This procedure has allowed: 1) to define some Alpine thrusts as inverted Permo-Carboniferous normal faults, 2) to constrain the age of several Permo-Carboniferous faults, 3) to differentiate the area studied as a volcano-tectonic depression, independent of the western part of the Erill Castell-Estac basin, and 4) to establish the paleogeographic position of the Permo-Carboniferous series and the minimum dimensions for the part of the basin studied.