LOESS IN IRAN

The loess regions along the southern Caspian Lowlands and in the Basin of Persepolis are among the southernmost one of the Northern Hemisphere representing important spatial links between Southeast Europe and Central Asia. These loess records reflect several cycles of climate change and landscape evolution during the Middle to Upper Pleistocene as well as during the Holocene highlighting that loess represents one of the most important geoarchives which records past climate and past environment change in the region.

Radiometric methods such as luminescence and radiocarbon dating have been applied to establish more reliable chronological frameworks to better constrain reconstructions of past climate and environment change and compare and correlate those to Southeast European and Central Asian high resolution records. Kehl et al. (2005) and Frechen et al. (2009) suggested that in Northern Iran during the last interglacial/glacial cycle, periods of increased dust accumulation and soil formation are synchronous with those recorded in Central and Southeast Europe including marine and ice core data as well as in Central Asia. The intensity of modern soil formation and those of past interstadial and interglacial conditions increases from north to south and from west to east is in agreement with the modern precipitation gradients from the Caspian Sea to the Alborz Mountains and from the Neka area to the semi-arid Turkmen Steppe, respectively.

The loess sequences of Neka, Toshan, Now Deh and Agh Band enable us to set up a high resolution record of dust accumulation and climate change for the Southeast Caspian Lowlands. Similarities and differences are compared to the Southeast European and Central Asian (Frechen & Dodonov 1998) loess records.

References Frechen, M. & Dodonov, A.E. (1998): Loess chronology of the Middle and Upper Pleistocene in Tadjikistan.- International Journal of Earth Sciences, 87: 2-20.

Frechen, M., M. Kehl, C. Rolf, R. Sarvati & A. Skowronek (2009): Loess chronology of the Caspian Lowland in Northern Iran. Quaternary International, 128: 220-233.

Kehl, M., Frechen, M. & Skowronek, A. (2005): Paleosols derived from loess and loess-like sediments in the Basin of Persepolis, Southern Iran.- Quaternary International, 140-141: 135-149.