Palaeosols are considered reliable archives of Quaternary climate changes provided they can be placed in a correct chronological framework. Until now the timing of soil formation in the arid regions of Iran is not well constrained. The objectives of this study are to (i) identify, study and correlate palaeosols from geographically different sites in arid regions of Iran, (ii) place them in a chronological framework and (iii) make use of the results for paleoclimate reconstruction. Ten representative pedons from Khorasan Rzavi (northeastern Iran), Kerman (Eastern Iran) and Esfahan (central Iran) provinces were described and sampled for geochemical analysis and luminescence dating. The paleosols contain a red argillic - calcic horizon (Btk)horizon which developed in old pediments and alluvial fans. All Btk horizons were morphologically similar between different sites; they were red in color (7.5 YR) and developed in gravelly and sand dominated parent material. Btk horizons are interpreted as the remnants of buried paleosols. In some cases, the Btk horizon appears to have been buried by a less developed soil containing a Bk horizon. Secondary carbonates were also observed as soft masses in Btk and Bk horizons. From field evidence, it is suggested that the paleosols in arid regions of Iran can be morphologically correlated and that they have experienced similar landscape evolution. Some studies in loess-paleosols in Iran [1-3] suggest that the Btk horizon developed during last interglacial peiod (MIS5) but no radiometric age control exists. It is thus hypothesized that the Btk horizon in the pedons likely developed in MIS5 (late Pleistocene) and the Bk horizon in more humid periods in MIS1 (early Holocene). To test this hypothesis we apply OSL dating to sand-sized (125-250 µm) quartz and feldspar grains extracted from the Btk and Bk horizons. Despite some difficulties encountered during samples preparation (especially removal of gypsum), preliminary results show that the quartz extracts are pure (no IR-sensitive component) and have a relatively bright, fast-component dominated signal. We report on quartz OSL and feldspar IRSL ages (to check for completeness of quartz bleaching, [4]) and interpret the ages in their pedological and stratigraphic contexts.

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