Structural Reconstruction of the Middle Uralian Part of the Uralian Orogen at the Initial Stage of Its Formation: Evidence from Clay Geochemistry.

The Uralian foredeep is a classical marginal structure located on the foreland of the Late Paleozoic Uralian Orogen. It is subdivided into several depressions/sedimentation basins. This paper presents the analysis of the REE and Th distribution in the Middle Carboniferous and Lower Permian clay rocks of the Yuryuzan–Sylva Depression. This structure, like other depressions of the foredeep, is made up of diverse associations of the first sedimentation cycle clastic and clay rocks, which were formed during the orogen erosion. In the (La/Yb)_N–Eu/Eu* and (La/Yb)_N–Th diagrams, individual and average data points are confined to the field of bottom sediments of mouths of modern rivers draining volcanic provinces. This likely suggests a homogeneous composition of orogen provenance in the Carboniferous and Early Permian. [ABSTRACT FROM AUTHOR]