Volcanism and evolution of the landscapes in Cappadocia

Cappadocia, situated in the Central Anatolia Plateau in Turkey, is characterized by widespread volcanic rocks (lavas, ignimbrites and pyroclastic deposits) alternating with fluvio-lacustrine sediments of Miocene (around 10 million years) to Quaternary age. The evolution of the Cappadocian landscape starts with gently sloping plateaus, which are then dissected, usually along fractures of soft-unwelded ignimbrites, to form mushroom-like, cone-shaped structures known locally as ‘fairy chimneys’. We present here a brief description of the stratigraphy of the Cappadocian volcanic succession and explain types of volcanic products. Different landforms created by the erosion of the volcanic rocks are also explained. Because of the favorable engineering properties of the ignimbrites, ancient populations have carved their houses, churches and even underground cities for centuries. Today, this unique cultural and morphological heritage site, classified under UNESCO World Heritage List since 1985, is one of the most visited regions of Turkey

La Cappadoce méridionale de la Préhistoire à l'époque byzantine

Il y a environ 25 ans, Olivier Pelon organisait à l’Institut Français d’Études Anatoliennes d’Istanbul un colloque destiné à faire l’état des recherches sur la Cappadoce méridionale jusqu’à la fin de l’époque romaine. Un quart de siècle après ce premier colloque, il était intéressant de faire un nouveau point sur l’avancée des recherches dans cette Cappadoce méridionale, de la préhistoire à la période byzantine. Ce nouveau colloque, placé cette fois encore sous l’égide de l’Institut Français d’Études Anatoliennes et intégré à la série des Rencontres d’archéologie de l’IFEA réunit vingt-trois communications. Si les périodes néolithique et chalcolithique ont été particulièrement bien représentées, ce qui témoigne bien de l’importance de cette phase de la préhistoire cappadocienne, liée aux gisements d’obsidienne des Melendiz Dağları, on soulignera en revanche l’absence presque totale du Bronze Ancien. Cette phase est en effet peu représentée dans l’archéologie locale. La même remarque peut s’appliquer au Bronze Moyen. La fin du Bronze Moyen, fort heureusement, est représentée à Porsuk, de même que le Bronze Récent qui bénéficie, depuis peu, tout comme l’Âge du Fer, du démarrage fructueux des fouilles de Kınık Höyük. Enfin, l’Antiquité tardive et Byzance ont pu être représentées, principalement autour de Tyane, ce qui n’avait pas pu être le cas lors du premier colloque. En octobre 2012, quelques semaines avant la tenue de la Rencontre, on apprenait malheureusement le décès brutal et inattendu d’Olivier Pelon, ancien directeur de la mission de Porsuk (jusqu’en 2002) et organisateur de ce premier colloque cappadocien. C’est bien en hommage à sa mémoire que notre Rencontre cappadocienne de 2012 et sa publication ont été naturellement dédiées

An early glacial maximum during the last glacial cycle on the northern Velebit Mt. (Croatia)

Comprehensive glacial Quaternary studies involving geochronological methods, modelling of ice topography with the support of field geomorphological and geological data in the Balkan Peninsula are relatively scarce, although there is evidence of past glaciations in severalmountain ranges. Here, we present research on the extent and timing of past glaciations on the northern Velebit Mt. in coastal Croatia and inferences of the climate during that time. Based on geomorphological and sedimentological evidence and using cosmogenic 36Cl surface exposure dating of moraine boulders, we provide an empirical reconstruction of past glaciers and compare this with the Parallel Ice Sheet Model (PISM) simulations under different palaeoclimate forcings. The dating results show that the northern Velebit glaciers reached their maximum extent during the last glacial cycle before the global Last Glacial Maximum (LGM). Maximum ice extent likely correlates with Marine Isotope Stage 5–4, although the exact timing cannot be determined at this point due to poorly known site- and time-specific denudation rates. Empirical reconstruction of the maximum extent suggests that the area covered by glaciers was ~116 km2. The-best fit PISM simulation indicates that the most likely palaeoclimate scenario for the glaciers of this size to form is a cooling of ~8 °C and a 10% reduction in precipitation from present-day levels. However, the best-fit simulation does not correctly model all mapped ice margins when changes in climatological parameters are applied uniformly across the model domain, potentially reflecting a different palaeoprecipitation pattern to today

River, alluvial fan and landslide interactions in a tributary junction setting: Implications for tectonic controls on Quaternary fluvial landscape development (Central Anatolian Plateau northern margin, Turkey)

Along the western flank of the northern margin (Central Pontides) of the Central Anatolian Plateau, the humidity from the Black Sea is much higher than the central and eastern flanks and creates a complex relationship between surface and tectonic processes by triggering intense mass wasting activity and aggradation within narrow valleys. We identified three incised fill terrace levels and used Optically Stimulated Luminescence (OSL) dating to calculate fluvial sediment ages and cosmogenic 36Cl exposure dating to calculate limestone boulders exposure ages across the terrace surface. Stratigraphical interpretations and OSL ages of the lowest levels revealed that a fluvial fill terrace formed in the main valley at 275.6 ± 12.8 ka and was overlain by a main river-tributary junction alluvial fan that was abandoned at 39.5 ± 3.5 ka. The results collectively show the influence of climate, topography, hillslope processes, and lithology on aggradation-incision patterns of main rivers. Prolonged aggradation can prevent the channel equilibrium required to calculate rock uplift rates while also causing a new base-level and aggradation upstream. This effect can be exacerbated in uplifting mountainous regions with limited depositional areas. Bedrock incision rates based on the fluvial terrace age were between 0.15 and 0.2 mm/a since 39.5 ± 3.5 ka. However, the high aggradation within this segment of the main valley prevented incision of the channel bedrock for long periods, causing a potential underestimation of the rock uplift rate calculation. Our local period of aggradation appears to be related to increased aggradation and decreased bedrock incision rates measured 14 km upstream that were previously assumed to be the result of decreased tectonic uplift rates. This demonstrates the importance of corroborating strath terrace incision rate estimations with ages and incision rates of downstream fill terraces, if present, to check for potential interference with the tectonic signal.This work was supported by the European Commission within the Marie Curie-ITN ALErT Project [grant number FP7-PEOPLE-2013-ITN , number 607996] and the Istanbul Technical University BAP Project [grant number TDK-2017-40776 ]. We would also like to thank the CNRS-ASTER Laboratory in Aix en Provence France for AMS measurements and AcmeLabs, Canada for measurements of major and trace element concentrations. Reviews by the Geomorphology editor, Sarah Boulton (University of Plymouth), Tim Barrows (University of Wollongong), and an anonymous reviewer have greatly helped to improve the content of this work.This work was supported by the European Commission within the Marie Curie-ITN ALErT Project [grant number FP7-PEOPLE-2013-ITN, number 607996] and the Istanbul Technical University BAP Project [grant number TDK-2017-40776]. We would also like to thank the CNRS-ASTER Laboratory in Aix en Provence France for AMS measurements and AcmeLabs, Canada for measurements of major and trace element concentrations. Reviews by the Geomorphology editor, Sarah Boulton (University of Plymouth), Tim Barrows (University of Wollongong), and an anonymous reviewer have greatly helped to improve the content of this work.Publisher's Versio

Carbonate and silicate intercomparison materials for cosmogenic ³⁶Cl measurements

Two natural mineral separates, labeled CoCal-N and CoFsp-N, have been prepared to serve as intercomparison material (ICM) for in situ-produced cosmogenic ³⁶Cl and natural chlorine (Clnat) analysis. The sample CoCal-N is derived from calcite crystals in a Namibian lag deposit, while the sample CoFsp-N is derived from a single crystal of alkali-feldspar from a Namibian pegmatite. The sample preparation took place at the University of Cologne and a rotating splitter was used to obtain homogeneous splits of both ICMs. Forty-five measurements of CoCal-N (between 1 and 16 per facility) and forty-four measurements of CoFsp-N (between 2 and 20 per facility) have been undertaken by ten target preparation laboratories measured by seven different AMS facilities. The internal laboratory scatter of the ³⁶Cl concentrations indicates no overdispersion for half of the laboratories and 3.9 to 7.3% (1σ) overdispersion for the others. We show that the CoCal-N and CoFsp-N splits are homogeneous regarding their ³⁶Cl and Clnat concentrations. The grand average (average calculated from the average of each laboratory) yields initial consensus ³⁶Cl concentrations of (3.74 ± 0.10) × 10⁶ at ³⁶Cl/g (CoCal-N) and (2.93 ± 0.07) × 10⁶ at ³⁶Cl/g (CoFsp-N) at 95% confidence intervals. The coefficient of variation is 5.1% and 4.2% for CoCal-N and CoFsp-N, respectively. The Clnat concentration corresponds to the lower and intermediate range of typical rock samples with (0.73 ± 0.18) µg/g in CoCal-N and (73.9 ± 6.8) µg/g in CoFsp-N. We discuss the most relevant points of the sample preparation and measurement and the chlorine concentration calculation to further approach inter-laboratory comparability. We propose to use continuous measurements of the ICMs to provide a valuable quality control for future determination of ³⁶Cl and Clnat concentrations