The Gediz River fluvial archive: A benchmark for Quaternary research in Western Anatolia

Abstract

Additional information:Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. ABSTRACTThe Gediz River, one of the principal rivers of Western Anatolia, has an extensive Pleistocene fluvial archive that potentially offers a unique window into fluvial system behaviour on the western margins of Asia during the Quaternary. In this paper we review our work on the Quaternary Gediz River Project (2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010) and present new data which leads to a revised stratigraphical model for the Early Pleistocene development of this fluvial system.In previous work we confirmed the preservation of eleven buried Early Pleistocene fluvial terraces of the Gediz River (designated GT11, the oldest and highest, to GT1, the youngest and lowest) which lie beneath the basalt-covered plateaux of the Kula Volcanic Province. Deciphering the information locked in this fluvial archive requires the construction of a robust geochronology. Fortunately, the Gediz archive provides ample opportunity for ageconstraint based upon age estimates derived from basaltic lava flows that repeatedly entered the palaeo-Gediz valley floors. In this paper we present, for the first time, our complete dataset of 40 Ar/ 39 Ar age estimates and associated palaeomagnetic measurements. These data, which can be directly related to the underlying fluvial deposits, provide age constraints critical to our understanding of this sequence.The new chronology establishes the onset of Quaternary volcanism at ~1320ka (MIS42). This volcanism, which is associated with GT6, confirms a pre-MIS42 age for terraces GT11-GT7. Evidence from the colluvial sequences directly overlying these early terraces suggests that they formed in response to hydrological and sediment budget changes forced by climatedriven vegetation change. The cyclic formation of terraces and their timing suggests they represent the obliquity-driven climate changes of the Early Pleistocene. By way of contrast the GT5-GT1 terrace sequence, constrained by a lava flow with an age estimate of ~1247ka, span the time-interval MIS42 -MIS38 and therefore do not match the frequency of climate change as previously suggested. The onset of volcanism breaks the simple linkage of terracing to climate-driven change. These younger terraces more likely reflect a localized terracing process triggered by base level changes forced by volcanic eruption and associated reactivation of pre-existing faults, lava dam construction, landsliding and subsequent lavadammed lake drainage.Establishing a firm stratigraphy a...

Mantle Sources of Recent Anatolian Intraplate Magmatism: A Regional Plume or Local Tectonic Origin?

“…In the Kula volcanic field, lavas were emplaced along active normal faults associated with the E-W trending Alaşehir graben, one of the main E-W trending structures that developed under the late Miocene-Quaternary N-S extensional regime in western Anatolia (Alıcı et al, 2002;Yilmaz et al, 2000). The Kula volcanics represent the youngest magmatic activity in the region (1.9-0.026 Ma; Grützner et al, 2013;Maddy et al, 2015Maddy et al, , 2017Richardson-Bunbury, 1996), with the main phase of volcanic activity having started at~0.2 Ma (Bunbury et al, 2001). In contrast to the older, surrounding volcanics regions in western Anatolia, which are dominated by potassium-rich magmas with typically orogenic signatures (e.g., Ersoy et al, 2012;Innocenti et al, 2005;Lustrino & Wilson, 2007;Prelević et al, 2012), the Quaternary Kula volcanics form a primitive, silica-undersaturated Na-alkaline suite (Alıcı et al, 2002;Richardson-Bunbury, 1996;Tokçaer et al, 2005) and are generally relatively unevolved (MgO = 4-8 wt%; Innocenti et al, 2005).…”

Yeşilırmak Taraçalarında (Orta Kuzey Anadolu) Geç Pleyistosen İklim Değişiklikleri ve Düşey Yönlü Deformasyona Akarsu Cevabının Araştırılması

“…Especially the intense erosional (humid) LGM period is also clearly evident in adjacent paleoclimate archives ( Figure 8). Despite a significant drop in Black Sea Level (Panin and Popescu, 2007), there is an apparent rise in lake levels (Lake Van;Çağatay et al, 2014;Lake Lisan, Torfstein et al, 2013;Lake Konya;Fontugne et al, 1999) and glaciers in Anatolian mountains advancing to their maximum (Sarıkaya and Çiner, 2015). Post-LGM, the region witnessed a severely cold and dry period, at ca.18.5±2.1 ka, which is evident in fluvial architecture of T1 and also with a 2 m thick loess deposit overlying the T2 terrace (Figure 5 B and D).…”

Structural, lithological, and geodynamic controls on geothermal activity in the Menderes geothermal Province (Western Anatolia, Turkey)

“…Pliocene and Quaternary); the unique volcanic activity occurred in the Kula volcanic field during the Quaternary between 2 and 0.2 Ma (e.g. Richardson-Bunbury 1996;Bunbury et al 2001;Maddy et al 2017) where geothermal activity is absent.…”