Palaeoenvironmental reconstructions in drylands – an example from the Binaloud Mountains in northeastern Iran

Fluvial sediments are valuable paleoenvironmental archives of the Quaternary. Since they are also affectedby local tectonics or intrinsic processes, large instead of small catchments should be studied. Large riversystems are often missing in drylands, and most river systems are small rivers originating from mountainranges. Their sediments are potentially interesting paleoenvironmental archives, but are often affected byintensive tectonics. Here, to obtain a robust regional paleoenvironmental signal a small river system in thesouthwestern Binaloud Mountains in semi-arid NE Iran was exemplarily studied with a whole-catchmentapproach encompassing both alluvial fan and catchment. Using geomorphological mapping and numericaldating, fluvial aggradation and subsequent incision were independently identified in larger areas or indifferent parts of the river system ca. ۹۵ – ۸۸ ka, ۴۰ ka, ۲۰ ka, around/after the Pleistocene/Holocenetransition and possibly ca. ۲.۶ ka. These could be linked with regional paleoenvironmental changes andglobal environmental data. Furthermore, large boulders on the alluvial fan suggest anthropogenicdestabilisation of the catchment during the last decades. Despite strong local tectonics the fluvial dynamicswas mostly controlled by paleoenvironmental changes. This indicates that despite their small size suchriver systems form valuable paleoevironmental archives in drylands where other archive types are largelymissing. Keywords: Fluvial geomorphology, paleoenvironmental reconstruction, drylands, LateQuaternary, tectonics, alluvial fans, Iran.