Climatic interpretation of loess-paleosol sequences at Mobarakabad and Aghband, Northern Iran

Abstract

Loess accumulation and paleosol formation are important Quaternary geoarchives in northern Iran. Two loess-paleosol sequences at Mobarakabad and Aghband were examined using soil morphology and micromorphology, mineralogy, magnetic susceptibility (MS), free Fe oxides and calcium carbonate equivalent. The loess-paleosol sequences provide a record of changes in paleo-rainfall in the northern Iran. Micromorphological and MS differences between the loess and paleosols in the sections reflect changes in climate. The different behaviors of magnetic susceptibility between Aghband and Mobar-akabad loess are mainly produced by their different pedogenic environments, topography and climatic conditions. As a result, the MS at the Mobarakabad section is much higher than at Aghband. Paleoeco-logical reconstructions coupled with magnetic depletion in paleosols at Mobarakabad suggest a wetter climate dominating during the formation of the paleosols.

Approaches and challenges to the study of loess—Introduction to the LoessFest Special Issue

“…Proxy data relating to paleoenvironmental conditions relating to temperature, precipitation, influence of specific climate subsystems, and geomorphic stability are so far limited. Data are limited either through lack of direct chronological information (Vandenberghe et al, 2006; Yang and Ding, 2006; Yang et al, 2006; Machalett et al, 2008) or because of insufficient chronological depth of the available paleoenvironmental proxies (Dodonov et al, 2006; Feng et al, 2011; Fitzsimmons et al, 2016; Ghafarpour et al, 2016).…”

The δ13C, δ18O and Δ47records in biogenic, pedogenic and geogenic carbonate types from paleosol-loess sequence and their paleoenvironmental meaning

“…Paleosol-loess sequences have a long history of use in paleoenvironmental reconstructions for a broad range of paleoclimate, geology, biology, and anthropology investigations (e.g., Riecken, 1950;Fisk, 1951;Kyuma et al, 1985;Wu et al, 2007;Zech et al, 2012;Lechler et al, 2018). The worldwide spatial distribution (Haase et al, 2007;Muhs, 2007;Roberts et al, 2013;Ghafarpour et al, 2016) and high temporal resolution (Frechen et al, 2003;Karimi et al, 2011;Sun et al, 2012;Taheri et al, 2016;Moine et al, 2017) of paleosol-loess sequences make them an important terrestrial archive (Guo et al, 2002). To this end, investigating isotopic compositions of carbon (δ 13 C carb ) and oxygen (δ 18 O carb ) of loess materials, and in particular carbonates formed in these sequences, has been a staple of paleoenvironmental reconstructions for decades.…”

Constraining the timing of palaeosol development in Iranian arid environments using OSL dating

“…Most of the palaeoclimatic studies in Iran have been based on geomorphic and pedogenic evidence (e.g. Karimi et al, 2009;Khormali and Kehl., 2011;Farpoor et al, 2012;Ghafarpour et al, 2016). A few studies have applied absolute dating methods to studying palaeoenvironmental and landscape change in Iran (Kehl et al, 2005;Frechen et al, 2009;Karimi et al, 2011;Lauer et al, 2016;Büdel et al, 2017), but most focus on the loess-M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 4 palaeosol sequences of Northern and Northeast of Iran (e.g.…”