Landscape evolution in the northeastern Iranian Plateau reconstructed from Late Pleistocene to Holocene sediment archives

点击翻译按钮获取中文摘要

Very few studies on reconstructing landscape evolution inferred from Late Pleistocene and Holocene sediment archives in the Iranian highlands were conducted so far. Primarily, this is due to the limited significance of terrestrial sediments from semi-arid environments. In contrast to lake sediments, they bear poor amounts of biogenic environmental and climate proxy indicators, but anyway provide essential information for reconstructing past environmental and climatic conditions. Restrictions range from difficult access to an important archive, to extreme environmental conditions with temporally and spatially diverging morphodynamic conditions and to complications during data interpretation, which are following these archive discontinuities.However, detailed analysis of Quaternary relief features allows for a combined examination of multiple geological archives and thus enables a synthesis from conclusions about the predominating environmental conditions during their formation. This way, even geological archives with limited coverage in space and time and only sporadic appearance connect efficiently for an extensive paleo environmental reconstruction. One of the most important aspects here is the precise determination of the time of deposition, as a correlation of the diverging sediment facies is very limited otherwise. Therefore, the chronostratigraphic classification of the archives is a crucial part of the correlation and combination of their individual paleoenvironmental signals.In course of the applied project, effect and extent of the post-LGM lake level retreat within the Bajestan Playa in the northeastern Iranian Bardeskan Basin will be determined. This will provide a base for the reconstruction of regional and supraregional tendencies of late Pleistocene and Holocene environmental change. Notably at the southern border of today’s playa, a rich inventory of mostly erosional and deflational landforms has developed in course of the lake level retreat, which keeps record of the most recent landscape evolution. A prevailing relief inversion took place at the transition zone to the distally dissected alluvial fan and plain, and left an extraordinary convenient situation of outcrops. This shall now be utilised for detailed geomorphological, stratigraphical and chronostratigraphical studies, in order to reconstruct the course of the lake level retreat and the subsequent landform succession.