Based on historical and instrumental data, societies in the Eastern Mediterranean and MiddleEast have survived at least 150 large earthquakes (generally M > 6) during the past 2500 yr. Beyond this time span, an earthquake chronology is mostly unknown, which hampers the production of reliable long-term earthquake models. Since the only remaining evidence of seismic activity is a bedrock scarp, cosmogenic 36 Cl is the only suitable nuclide to be applied in the determination of the seismic history and slip rate of an active limestone fault plane. In this study, we focus on the 4-m-high Mugırtepe fault scarp within the active Manisa fault zone in western Anatolia, one of the most seismically active and rapidly extending regions in the world. We analyzed 44 samples in two slightly overlapping strips, which in total covered 2.65 m of the fault scarp. In order to determine the timing and the amount of slip of the paleoseismic events, we analyzed the measured 36 Cl concentrations using the Schlagenhauf Matlab ® code. We used two different scenarios based on two different inherited 36 Cl concentrations as constrained by our data and modeling. The best fi t for the fi rst scenario yields two seismic events, one at 13.7 ± 0.8 ka with a displacement of 0.5 ± 0.2 m and one at 7.8 ± 0.5 ka with 2.15 ± 0.35 m offset. For the second scenario, we obtained a single seismic event at 8.6 ± 0.6 ka with 2.65 ± 0.35 m of slip. These results indicate that the visible part of the Mugırtepe exposed fault scarp had achieved most of its displacement already by 8 ka. Initial surface faulting at Mugırtepe occurred not later than around 14 ka, and marked seismic activity continued until around 8 ka. Our fi rst results from the western Anatolian Extensional Province show the ability to reveal periods of enhanced seismic activity beyond historical data using cosmogenic 36 Cl.

We used cosmogenic 10 Be and 36 Cl to establish the timing of the onset of deglaciation after the Last Glacial Maximum of the Reuss Glacier, one of the piedmont lobes of the Alpine ice cap that reached the northern Alpine foreland in Switzerland. In this study, we sampled erratic boulders both at the frontal position in the foreland (Lenzburg and Wohlen, canton Aargau) and at the lateral Alpine border position (Seeboden moraine, Rigi, canton Schwyz). The minimum age for the beginning of retreat is 22.2 ± 1.0 ka at the frontal (terminal) position and 20.4 ± 1.0 ka at the lateral position. These ages are directly comparable with exposure ages from the other piedmont lobes in the northern Alpine foreland. Our data from the mountain called Rigi, do not support the hypothesis that boulders located external to the Seeboden moraine were deposited prior to the last glacial cycle. We present a first exposure age from an erratic boulder in a retreat position in the Alpine foreland. The Reuss Glacier was approximately 12 km behind the maximal extent no later than at 18.6 ± 0.9 ka.

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