Palaeosols, peat and the shredded climate signal: time resolution in an Early Jurassic fluvial landscape (Reșița Basin, South Carpathians)

Sedimentological analysis of the Lower Jurassic (Hettangian–Sinemurian) continental deposits of the Steierdorf Formation from the South Carpathian Getic Nappe (Anina area) reveals a fluvial–overbank depositional system containing numerous palaeosols, coal seams and well-preserved plant remains. This study aims to assess the time resolution and preservation of allogenic (primarily climatic) signals within such environments through an integrated sedimentological, palaeopedological, mineralogical and petrographic approach. The fluvial deposits are dominated by fine- to coarse-grained lithologies, interpreted as reflecting a low- to moderate-discharge system, possibly braided in character. Five palaeosol types (pedotypes) were identified, characterized by kaolinite-rich layers yet exhibiting limited sedimentary maturity and poor kaolinite crystallinity, suggesting reworked or composite soil formation. Coal deposits, in contrast, do not indicate any reworking. The palaeosols and palaeopeat layers are interpreted as time-condensed intervals with the potential for climatic signal-shredding due to erosion and reworking. The concept of ‘palaeoenvironmental palaeosnaps’ is used to describe high-resolution, discontinuous palaeoenvironmental archives common in continental settings. This study highlights the complexity and inherent uncertainties associated with interpreting palaeoclimatic proxies in fluvial successions.