Geochronology and petrology of recent volcanics in the eastern Aegean Sea (West Anatolia and Lesvos Island)

Borsi, S.; Ferrara, G.; Innocenti, Fabrizio; Mazzuoli, R.

doi:10.1007/bf02597122

Cited by 198 publications

(139 citation statements)

References 29 publications

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“…Twenty-five lavas were sampled in the volcanic center of Dikili, which was described in detail by Karacik et al [2007], with ages of 15-18 Ma [Borsi et al, 1972;Benda et al, 1974;Aldanmaz et al, 2000]. Finally, 17 lavas were sampled in the Yuntdağ volcanic region (Figure 2).…”

Section: Samplingmentioning

confidence: 99%

Exhumation with a twist: Paleomagnetic constraints on the evolution of the Menderes metamorphic core complex, western Turkey

et al. 2010

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Much remains to be understood about the links between regional vertical axis rotations, continental extension, and shortening. In western Turkey, Miocene vertical axis rotations have been reported that occur simultaneously with the extensional exhumation of the Menderes metamorphic core complex, which has been related to back‐arc extension in the eastern part of the Aegean back arc. In this paper we explore the spatial and temporal relationships between vertical axis rotations in southwestern Turkey and extensional unroofing of the Menderes Massif. To this end, we provide a large set of new paleomagnetic data from western Turkey, and integrate these with the regional structural evolution to test the causes and consequences of oroclinal bending in the Aegean region. The Lycian Nappes and Bey Dağları are shown to rotate ∼20° between 16 and 5 Ma, defining the eastern limb of the Aegean orocline. This occurred contemporaneously with the exhumation of the central Menderes Massif (along extensional detachments) and after the latest Oligocene to early Miocene exhumation of the northern and southern Menderes massifs. Exhumation of the latter two was not associated with vertical axis rotations. The lower Miocene volcanics in the region from Lesbos to Uşak, to the north of the central Menderes Massif underwent a small clockwise rotation, insignificant with respect to Eurasia. This shows that exhumation of the central Menderes Massif was associated with a vertical axis rotation difference between the northern and southern Menderes massifs of ∼25°–30°. This result is in excellent agreement with the angle defined by the trends of Büyük Menderes and Alaşehir detachments, as well as the angle defined by the regionally curving stretching lineation pattern across the central Menderes Massif. These structures define a pivot point (rotation pole) for the west Anatolian rotations. The rotation of the southern domain, including the southern Menderes Massif, the Lycian Nappes, and Bey Dağları, must have led to N–S contraction east of this pole. The eastern limit of the rotating domain is formed by the transpressional couple of the Aksu thrust and Kırkkavak Fault in the center of the Isparta angle. Previously reported clockwise rotations in the volcanic fields near Afyon may be the result of distributed N–S shortening east of the pivot point. The precise accommodation of this shortening history remains open for investigation. Late Oligocene to early Miocene extension in the eastern part of the Aegean back arc was NE–SW oriented and likely bounded by a discrete transform. This transform may be associated with an early evolution of the eastern Aegean subduction transform edge propagator fault. Oroclinal bending in the west Anatolian region is likely related to a reconnection of the eastern part of the Aegean orocline with the African northward moving plate in tandem with roll back in the Aegean back arc, comparable to a recently postulated scenario for western Greece.

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Section: Samplingmentioning

confidence: 99%

Exhumation with a twist: Paleomagnetic constraints on the evolution of the Menderes metamorphic core complex, western Turkey

et al. 2010

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“…Distribution of the volcanic rocks is modified from MTA 1/500,000 scale geological map of Turkey. The summarized ages are from Borsi et al (1972), Besang et al (1977), Pişkin (1980), Sunder (1980), Paton (1992), Ercan et al (1996), Seyitoglu et al (1997), Aldanmaz et al (2000), Ercan et al (2000), Helvacı and Alonso (2000), Robert and Montigny (2001), Erkül et al (2005), Purvis et al (2005), Innocenti et al (2005), Westaway et al (2005), Ersoy et al (2008), Helvacı et al (2009), Ersoy et al (2010b) and Karaoglu et al (2010) Fig. 2 a Na 2 O ?…”

Section: Introductionmentioning

confidence: 99%

High-K volcanism in the Afyon region, western Turkey: from Si-oversaturated to Si-undersaturated volcanism

Akal

Helvacı

Prelević³

et al. 2012

Int J Earth Sci (Geol Rundsch)

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Volcanic rocks of the Afyon province (eastern part of western Anatolia) make up a multistage potassic and ultrapotassic alkaline series dated from 14 to 12 Ma. The early-stage Si-oversaturated volcanic rocks around the Afyon city and further southward are trachyandesitic volcanic activity (14.23 ± 0.09 Ma). Late-stage Si-undersaturated volcanism in the southernmost part of the Afyon volcanic province took place in three episodes inferred from their stratigraphic relationships and ages. Meliliteleucitites (11.50 ± 0.03 Ma), spotted trachyandesites, tephryphonolites and lamproites (11.91 ± 0.13 Ma) formed in the first episode; trachyandesites in the second episode and finally phonotephrites, phonolite, basaltic trachyandesites and nosean-bearing trachyandesites during the last episode. The parameter Q [normative q-(ne ? lc ? kls ? ol)] of western Anatolia volcanism clearly decreased southward with time becoming zero in the time interval 10-15 Ma.

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“…The youngest and freshest basalts were attributed to the ß4 group and all basalts at heights intermediate between the two, and more weathered than the youngest grouping, were attributed to the ß3 group (Figure 3). A Page 9 of 61 K-Ar age estimate of 1100ka (Borsi et al, 1972, no error margin given) from a ß2 flows (sampling location is uncertain) in the study area was Early Pleistocene in age, thus establishing a Quaternary assignment for all of the basalts of the study area.…”

Section: Quaternary Geology and The Gediz Valley Formationmentioning

confidence: 96%

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

Maddy

Veldkamp

Demi̇r

et al. 2017

Quaternary Science Reviews

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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...

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Geochronology and petrology of recent volcanics in the eastern Aegean Sea (West Anatolia and Lesvos Island)

Cited by 198 publications

References 29 publications

Exhumation with a twist: Paleomagnetic constraints on the evolution of the Menderes metamorphic core complex, western Turkey

Exhumation with a twist: Paleomagnetic constraints on the evolution of the Menderes metamorphic core complex, western Turkey

High-K volcanism in the Afyon region, western Turkey: from Si-oversaturated to Si-undersaturated volcanism

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

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