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Turkish Journal of Earth Sciences(Turkish J. Earth Sci.), Vol. 14,2005, pp. 145—166.Copyright 'T(cid:134)B(cid:220)TAK Geotectonic Setting and Origin of the Youngest Kula Volcanics (Western Anatolia), with a New Emplacement Model MURAT TOK(cid:130)AER1, SAMUELE AGOSTINI2& MEHMET YILMAZ SAVA(cid:222)(cid:130)IN1 1 Dokuz Eyl(cid:159)l (cid:134)niversitesi, M(cid:159)hendislik Fak(cid:159)ltesi, Jeoloji M(cid:159)hendisli(cid:219)i B(cid:154)l(cid:159)m(cid:159), Bornova, TR—35100 (cid:220)zmir, Turkey (E-mail: [email protected]) 2University of Pisa, Istituto di Geoscienze e Georisorse-CNR, Department of Earth Sciences, Pisa I-56124, Italy Abstract:The Quaternary Kula volcanics are Na-dominant in character while all the older volcanic rocks of western Anatolia are generally definitive K-dominant rocks. As a unique example in western Anatolia, the existence of a huge amount of plateau basalts at Kula indicates rapid uplift of mantle material, as confirmed by new geochemical data. Based on our field observations, the oldest Kula volcanics are the plateau basalts with more than one main lava flow. At the beginning of volcanic activity (first-period plateau basalts), this plateau was vast. Subsequently, parts of the first-period plateau basalts were uplifted and partly eroded while other parts were covered by younger lavas, tephra and sediments. The horsts, covered by plateau basalts, are well protected because of their resistance to erosion. During extensional activity, the development of cinder cones continued without hiatus. During the last period of volcanic activity, the youngest craters once again produced lava flows to form the second-period plateau basalts. As a result, there are more than 80 cinder cones with quite different erosional stages between the first and second plateau-basalt periods. The Kula basalts are the only example of rapid uplifting of asthenospheric material in western Anatolia, and are interpreted to form due to the opening of a horizontal slab window as a consequence of the more rapid southwestward movement of the Aegean microplate overriding Africa, with respect to the Anatolian plate. Key Words:western Anatolia, extensional tectonics, Kula volcanics, geochemistry Gen(cid:141) Kula Volkaniklerinin Jeotektonik Konumu, K(cid:154)keni ve Yeni Yerle(cid:223)im Modeli (Bat(cid:221) Anadolu) (cid:133)zet:Kuvaterner ya(cid:223)l(cid:221) Kula volkanikleri Na(cid:213)ca bask(cid:221)n karakterde olmalar(cid:221)na kar(cid:223)(cid:221)n (cid:154)nceki di(cid:219)er t(cid:159)m Bat(cid:221) Anadolu volkanikleri K(cid:213)ca egemen volkanik kayalard(cid:221)r. Bat(cid:221) Anadolu i(cid:141)in tek bir (cid:154)rnek olan bu b(cid:159)y(cid:159)k miktardaki plato bazaltlar(cid:221)n(cid:221)n varl(cid:221)(cid:219)(cid:221) jeokimya sonu(cid:141)lar(cid:221) ile de desteklenen h(cid:221)zl(cid:221) bir manto materyalinin y(cid:159)kselimini i(cid:223)aret eder. En ya(cid:223)l(cid:221) Kula volkanikleri, birden fazla lav ak(cid:221)nt(cid:221)s(cid:221)ndan olu(cid:223)an plato bazaltlar(cid:221)d(cid:221)r. Volkanik aktivitenin ba(cid:223)lang(cid:221)c(cid:221)nda geni(cid:223) bir yay(cid:221)l(cid:221)m sunan bu plato bazaltlar(cid:221) 1. evre plato bazaltlar(cid:221) olarak adlan(cid:221)rlar. Birinci evre plato bazaltlar(cid:221) kimi yerde y(cid:159)kselmi(cid:223) kimi yerlerde a(cid:223)(cid:221)nm(cid:221)(cid:223) ve kimi yerde ise daha gen(cid:141) lavlar ve tortullarca (cid:154)rt(cid:159)lm(cid:159)(cid:223)lerdir. Plato bazaltlar(cid:221) ile kapl(cid:221) horstlar bazaltlar(cid:221)n dayan(cid:221)ml(cid:221)l(cid:221)(cid:219)(cid:221)dan dolay(cid:221) cok iyi korunmu(cid:223)lard(cid:221)r. B(cid:154)lgedeki a(cid:141)(cid:221)lma d(cid:154)nemi s(cid:159)resince volkan konilerinin olu(cid:223)umu kesintisiz devam etmi(cid:223)tir. Volkanik aktivitenin son d(cid:154)neminde en gen(cid:141) volkan konileri bir kez daha lav (cid:159)reterek ikinci plato bazaltlar(cid:221)n(cid:221) olu(cid:223)turmu(cid:223)lard(cid:221)r. Bu iki plato bazalt evresi aras(cid:221)nda farkl(cid:221) a(cid:223)(cid:221)nma derecelerine sahip 80(cid:213)den fazla volkan konisi vard(cid:221)r. Kula bazaltlar(cid:221), Bat(cid:221) Anadolu(cid:213)da astenosferik mantonun h(cid:221)zl(cid:221) y(cid:159)kselmesine tek (cid:154)rnektir ve bu GB(cid:213)ya hareket eden Ege mikroplakas(cid:221)n(cid:221)n Afrika (cid:159)zerine bindirme h(cid:221)z(cid:221)n(cid:221)n, Anadolu plakas(cid:221)n(cid:221)n Afrika (cid:159)zerine bindirme h(cid:221)z(cid:221)ndan daha fazla olmas(cid:221) sebebiyle a(cid:141)(cid:221)lm(cid:221)(cid:223) olan bir (cid:141)e(cid:223)it yatay pencerenin varl(cid:221)(cid:219)(cid:221)na ba(cid:219)lanabilir. Anahtar S(cid:154)zc(cid:159)kler: Bat(cid:221) Anadolu, genle(cid:223)me tektoni(cid:219)i, Kula volkanikleri, jeokimya 145 NEW EMPLACEMENT MODEL FOR KULA VOLCANICS Introduction with some remarks. Canet & Jaoul (1946) remarked that cinder cones in the area are roughly situated on two The widely distributed small bodies of alkaline basalts straight lines whose strikes are sub-parallel to the graben occurring in all of the various sectors of the Aegean- edge. This is also observable on the geological map of the Anatolian realm are derived from OIB-type rocks. The area published by Hamilton & Strickland (1841). time-space distribution of volcanism in the Aegean and western Anatolia — with their main rock associations and Later researchers (Erin(cid:141) 1970; Ercan 1981) made a the involved magma sources — definitely show a transition similar classification of the basalts of the area with some from calc-alkaline, mantle-wedge source rocks to insufficient criticism of Hamilton & Strickland (1841). alkaline, OIB-type mantle-source rocks. Southwestward Recent studies of the tectonic setting and volcanism of the migration of calc-alkaline, shoshonitic and lamproitic Kula area have yielded diverse opinions. The most magmas in the hanging wall was accompanied by prominent neotectonic features of western Anatolia are southwestward migration of the subduction hinge. With a E—W-, NE—SW- and NW—SE-trending grabens (e.g., higher enrichment of the more incompatible elements, Ko(cid:141)yi(cid:219)it et al. 1999; Bozkurt 2000, 2001a, 2003; the trace-element distribution is similar to OIB-type Bozkurt & S(cid:154)zbilir 2004 and references there in). Shortly basalts as seen in the primordial-mantle (PM) normalized after the concentration of extension into two grabens ~ 2 spider diagrams. The mainly potassic alkaline-basaltic Ma, the generation of alkali-basalt magmas was magmatism, with its diverse geochemical compositions, generated in Kula area (Richardson-Bunbury 1996). reflects the extension-related activities prior to the Kula According to G(cid:159)len (1990), the Kula basalts contain volcanism. The sodic — phonolitic plateau basalts, craters, mantle xenoliths and represent volatile-rich, and lava flows of the Kula volcanics are therefore metasomatised asthenospheric melts (the best products of the final activity where the mostly representative mantle material in western Anatolia). uncontaminated material of the Aegean mantle rapidly Besides the geotectonic setting and origin of the Kula erupted as a new episode in a strongly extensional regime volcanics, explanation of the evolution of the volcanism during the neotectonic period. The stretching between and the emplacement of volcanic rocks in the Kula area is Greece and Anatolia, and the differential velocity of possible with some modifications of Hamilton & convergence with the underlying slabs, should have Strickland(cid:213)s model — another aim of the present study. generated (cid:212)horizontal windows(cid:213) both in the hanging wall The Kula volcanics are the youngest volcanic rocks of and in the footwall of the subduction, allowing western Anatolia and, in contrast to the older volcanics of asthenospheric upwelling and consequently its partial the area with their general potassic affinity, are mainly melting. Thus, the OIB magmatism was generated after sodic and have geochemical and isotopic characteristics regular subduction/collision evolution. With this new typical of OIB-type intraplate magmatism. model, it is much easier to explain the one-of-a-kind and characteristic evolution of the Quaternary Kula volcanics. Kula is a small town on the main (cid:220)zmir-Ankara road, Tectonic Framework of Western Anatolia which has a number of interesting volcanological aspects After the closure of N—dipping subduction zone between (Figure 1). The youngest volcanics of western Anatolia, the Pontides to the NNW and the Anatolide Tauride with widespread plateau basalts and well-preserved platform to the SSE (Late Palaeocene to Early Eocene), craters and lava flows, are excellent examples of an alkali- the (cid:220)zmir—Ankara suture zone was formed ((cid:222)eng(cid:154)r 1979; basalt province in an area of active rifting. These volcanics (cid:222)eng(cid:154)r & Y(cid:221)lmaz 1981). have been investigated by several researchers from the According to a new tectonic model, developed in order nineteenth century to present. to explain the Cenozoic magmatic activity of western The important tectonic, stratigraphic and Anatolia (Doglioni et al.2002) as the most prominent sedimentologic characteristics of the Kula volcanics were geodynamic factor in shaping the area, the African plate reported previously by Hamilton & Strickland (1841). (Cyprus-Aegean subduction zone) was subducted beneath According to those authors, topographic inversion of the the Greek and Anatolian microplates at different basalt stratigraphy within three periods is common in the velocities, causing a diffuse extensional margin between Kula area. Philippson (1914) confirmed this classification 146 M. TOK(cid:130)AER ETAL. a N Lesvos BLACKSEA İstanbul A A E E S ˙anakkale Ankara S N N EGEA İzmir GEA MANİSA Study A AE area İZMİR MEDITERRANEANSEA 0 320Km 0 40km b İZMNİRZ-OANNEKARA SİMAVGRABEN Simav G(cid:246)rdes Selendi m Da mirk(cid:246)pr(cid:252) De Salihli ALAŞEHİR KULA GRABEN Alaşehir 0 20km alluvium EarlyMiocene,normalfaults, probablesetsofreactivated Quarternarybasalt olderthrustfaults flowsandcones EarlyMiocene,normalfaults, Neogenesedimentary reactivatedthrustfaultbetween andcalc-alkalinevolcanic theMenderesMassifand rocks,Quaternarydeposits İzmir-AnkaraZone crystallinerocksofthe MenderesMassif, low-anglenormalfault Palaeogenegranitoids İzmir-AnkaraZone(İAZ): postulatedtensionfractures ultramafics,olistostrome leadingtobasalticeruptions Figure 1. Location of study area (a)with generalized geological map of the Kula area (b)(taken from Sava(cid:223)(cid:141)(cid:221)n et al.1999). 147 NEW EMPLACEMENT MODEL FOR KULA VOLCANICS the Aegean Sea and western Anatolia (Doglioni et al. and N—S- trending left-lateral transtensional faults 2002); considering Africa as fixed, the faster (Figure 3). southeastward motion of Greece relative to Cyprus- Such a post-orogenic extension, caused by the Anatolia determined the Aegean extension (Figure 2). In hanging-wall plate overriding the slab (Doglioni et al. this point of view, at least from the Early Miocene, the 2002), led to the coexistence of lacustrine sediments and previous horizontal NE—SW direction of the (—1) in the coeval volcanic rocks overlying the basement compressive stage become the trend of (—3), explaining (metamorphic rocks, ophiolitic nappes and flysch the formation of NW—SE-trending normal faults and sediments) — a typical section of western Anatolia grabens, E—W-trending right—lateral transtensional faults (Innocenti et al.2005). a N 0 40N X boundariesof ANATOLIA plates subductionzone GREECE extension zone 350N betweenGreece Aegean andAnatolia subduction Plate-motion AFRICAN ARABIA vectors X PLATE 250E 300E 350E 400E b SW NE compression extension Anatolia Africanplate Aegean lithosphere foldedslab? mantle asthenosphere X flow upwelling asthenosphere X Figure 2. (a)Considering a fixed Africa, Greece is overriding Africa faster than Cyprus and Anatolia. This implies extension between Greece and Anatolia (thick double arrow). Thin arrows indicate present-day plate-motion vectors with respect to a fixed Africa, inferred from space geodesy (Doglioni et al. 2002), after NASA data base (from http://sideshow.jpl.nasa.gov/mbh/series.html); (b) Schematic cross-section of overriding western Anatolia and Greece to African Plate. African slab should be folded by isostatic uplift of the mantle in the rift. This should result in a sort of window in the hanging-wall lithosphere that is splitting apart into two independent plates, i.e., Greece and Anatolia. It would hypothetically be coupled with a sort of horizontal window in the underlying stretched slab, allowing melting and ascent of OIB basalts (Doglioni et al.2002). 148 M. TOK(cid:130)AER ETAL. mildly alkaline rocks with mainly potassic (locally, also N sodic) affinity, forming scattered outcrops in western Anatolia and Aegean Sea (e.g., Ezine, Urla, Fo(cid:141)a, Bodrum, Dx transtension Karaburun, U(cid:223)ak, K(cid:159)tahya, Simav, Kaloyeri, Patmos). These products generally display a within-plate character, even if a slight subduction-related geochemical signature is also found locally. The radiometric ages from the second-stage alkaline volcanics (Borsi et al.1972; Benda n et al.1974; Besang et al.1976; Ercan et al.1985, 1997; o si n Seyito(cid:219)lu & Scott 1996; Innocenti et al. 2005) are e xt e consistent with those of the intercalating sediments. Indeed, according to new radiometric age determinations (Ercan et al.1997; Seyito(cid:219)lu et al.1997; Sx transtension Innocenti et al.2005) there is no significant time gap between the first-period volcanics of calc-alkaline to shoshonitic types and the succeeding ultrapotassic (U-K) Figure 3. Main trends and tectonic implications of and lamproitic types (Figure 4, columnar section). Some Miocene—Quaternary faults in the western Anatolia and Aegean areas (Doglioni et al.2002). new ages of these ultrapotassic shoshonitic and lamproitic rocks indicate that these rocks cropped out locally before The petrogenesis of the younger alkaline association the end of the first orogenic period (Table 1). and its relations with Neogene sedimentation and As a third phase of volcanism, the Na-basaltic rocks of extensional tectonics are reviewed in this study within the Kula cover an area over 350—400 km2, and are located at framework of the relative movements of the Aegean- the intersection of NE-trending tectonic lineaments with Anatolian, Eurasian and African plates. the youngest WNW-trending Ala(cid:223)ehir Graben (Figure 1b). This youngest volcanic field of western Anatolia comprises plateau basalts, several cinder and spatter Cenozoic Volcanism in Western Anatolia cones dating back to prehistoric times (Ercan et al.1985, Early to Middle Miocene orogenic magmatism was 1997; Bunbury 1992; Richardson-Bunbury 1996; followed by Late Miocene to Quaternary alkaline-basaltic Sava(cid:223)(cid:141)(cid:221)n et al.1999). volcanism (e.g., Francalanci et al.1990; Sava(cid:223)(cid:141)(cid:221)n & G(cid:159)le(cid:141) These temporal variations in volcanic phases are 1990; Y(cid:221)lmaz et al.2001). interpreted to have resulted from changing the The first calc-alkaline and shoshonitic rocks were geochemical features of the magma sources from supra- characterized by stratostratovolcano-type occurrences subduction (calc-alkaline to lamproitic associations) to and formed large centers with intercalated terrestrial sub-slab mantle (Agostini et al. 2003a, b). (1) In the sediments. Some investigators considered that these K- orogenic calc-alkaline and shoshonitic associations dominant, calc-alkaline to shoshonitic- type initial (mantle wedge metasomatized by subduction-related volcanics (23—15 Ma) were related to compressional components), 87Sr/86Sr and 143Nd/144Nd isotopic ratios and (subduction) tectonism (Dora et al.1987; Y(cid:221)lmaz 1989; trace—element variations suggest that interaction with the Sava(cid:223)(cid:141)(cid:221)n & G(cid:159)le(cid:141) 1990; Sava(cid:223)(cid:141)(cid:221)n 1990), while others crust was moderate, so that the geochemistry of these (Seyito(cid:219)lu & Scott 1992; Seyito(cid:219)lu et al. 1992) rocks is considered to reflect mainly the heterogeneous suggested that the entire Oligocene—Miocene volcanism of chemical nature of their mantle source. (2) The western Anatolia was related to the extensional tectonic ultrapotassic and lamproitic rocks are characterized by a regime. high 87Sr/86Sr and low 143Nd/144Nd isotopic ratios and are Following the Middle Miocene, basins were enlarged strongly enriched in K and Rb with respect to Ba, and they accumulated still thicker deposits. The second indicating a phlogopite-bearing lithospheric source. (3) phase was limited to the Middle Miocene—Early Pliocene The low 87Sr/86Sr and high 143Nd/144Nd isotopic ratios, and is characterized by the eruption of poorly evolved together with low LILE/HFSE ratios, reveal an OIB-type 149 NEW EMPLACEMENT MODEL FOR KULA VOLCANICS NANATOLIANNICS(WAV) VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV VVVVVVVVVVVVVV VVVVVVVVVVVVVV VVVVVVVVVVVVVVVVVVVVVVV BF:Burdurfault ASF:Alaşehir-Simavfault WAV:westernAnatolianvolcanics n taken from Agostini 2004). RA ee WESTEVOLC 2-0Ma 8.4Ma 5-14.2Ma 7-16.3Ma 18-15Ma 21-16Ma rocks dimentsedimentsans) ric ages have b ACKSEAN VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV V VVnVVVVVVVV15.VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV16.AVVVVVVVVVVVVVVVVSVVVVVVVVFVVVVVVVVVVVVVVVVVVVVVVVVVVVVV DITERRANEANSEA KshoshonitesVVVVVVVVVVcalc-alkalineVVVVVVVVVVVVVVVVVV Neogeneseper-alkalinerocks(lacustrinesmproitic,HK-UK)andalluvialf oshonitesbasement estern Anatolia with characteristic columnar sections (radiomet BL Kırka Afyo sparta FB ME U hy(la sh ks in w V V V V I VVV roc VVVVVWAVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVAkhisarVVVVVVVVVVVVVVVVVVKulaVVVVV Denizli VVQuaternaryVVsediments Kulavolcanics LateMiocenealkalinebasalts Distribution of Miocene volcanic AE S N EAE GEA V V 4. VVV e VVVVVV gur VVV Fi 150 M. TOK(cid:130)AER ETAL. Table 1. Some new age determinations from alkaline and hyper-alkaline rocks. Locality Rock Type Age (Ma) Data Source Akhisar UK-latite 16.9–0.3 Ercan et al.(1997) Akhisar UK-latite 16.72–0.15 Innocenti et al.(2005) Simav-Na(cid:223)a alkali basalt 15.2–0.3 15.8–0.3 Ercan et al.(1997) Selendi UK-rock 15.5–0.4 Seyito(cid:219)lu et al.(1997) G(cid:159)re lamproite 14.20–0.12 Innocenti et al.(2005) Il(cid:221)caksu lamproite 15.87–0.13 Innocenti et al.(2005) nature for the Kula volcanics, which originated from a Two different generalized stratigraphic columnar sub-slab asthenospheric mantle (Agostini et al.2003a, b; sections from Kula and surrounding area are given in Innocenti et al. 2005). Furthermore, ultrapotassic Figure 6a (Bunbury 1992) and Figure 6b (Kaya; an shoshonites and Upper Miocene basalts have been unpublished report for the Municipality of Kula). generated by interactions of source (1) with sources (2) Regionally metamorphosed units of the Menderes and (3), respectively (Agostini et al.2003a). crystalline rocks include gneiss, schist and marble (Brinkmann 1966; Dora et al.1987). This metamorphic basement is poorly exposed only in the southern part of Geology of the Kula Region the study area (W and E of Kula and Demirk(cid:154)pr(cid:159) Dam), Stratigraphy and Tectonics and is covered by listwaenite as relicts of the ophiolitic nappes (Kaya; an unpublished report for the Municipality The WNW-trending Simav and Ala(cid:223)ehir grabens of Kula), Neogene sediments and Kula volcanics. (Seyito(cid:219)lu 1997; Bozkurt 2001a, 2003; Seyito(cid:219)lu et al. Seismotectonic data indicate that the tilted Kula block 2004 and references therein), filled from Pleistocene to comprises up to 10—15 km of crystalline rocks from the present, are well represented by gravity anomalies upper crust (Eyido(cid:219)an 1988; Taymaz et al.1991). (Sava(cid:223)(cid:141)(cid:221)n et al.1999) and bound the study area to the north and south, respectively (Figure 1b). Kula is located Following tilting and uplifting of the Menderes Massif on a block of crystalline rocks of the Menderes Massif assemblage, there was a a period of erosion in Kula (e.g., Bozkurt 2001b; Bozkurt & Oberh(cid:138)nsli 2001; (Richardson-Bunbury 1996; Tok(cid:141)aer 2000). Small hills Erdo(cid:219)an & G(cid:159)ng(cid:154)r 2004; Koralay et al.2004; Seyito(cid:219)lu were formed in the peneplain. Fluviatile and overlying et al.2004 and references therein), which is delimited by lacustrine sediments of Neogene age include a southward-tilted footwall block of the Simav Graben or conglomerate, sandstone, limestone and marl. a southward-tilted hanging-wall block of the Ala(cid:223)ehir The Kula area is characterized tectonically by regularly graben (Figure 5). The readers are referred to recent ordered NE-trending normal faults that separate the literature about the continental extensional tectonics in crystalline rocks, the Neogene sediments and the western Turkey and the Menderes Massif (Bozkurt volcanics from one another. According to Sava(cid:223)(cid:141)(cid:221)n et al. 2001b, 2003, 2004; Bozkurt & Oberh(cid:138)nsli 2001; (1999), they acted as growth faults during the Miocene. Seyito(cid:219)lu et al.2002, 2004; Akal 2003; Altunel et al. NE-trending gravitational anomalies coincide in most 2003; England 2003; I(cid:223)(cid:221)k et al. 2003, 2004; places with these NE-trending fault blocks (Sava(cid:223)(cid:141)(cid:221)n et al. Karamanderesi & Helvac(cid:221) 2003; Ko(cid:141)yi(cid:219)it & (cid:133)zacar 2003; 1999). This NE-trending fault system reflected an older Lenk et al.2003; Westaway 2003; Bozkurt & S(cid:154)zbilir graben—horst structure with older Neogene sediments 2004; Erdo(cid:219)an & G(cid:159)ng(cid:154)r 2004; Kaya et al. 2004; and, in the Kula region, have been partially reactivated in Koralay et al.2004 and references therein). the Quaternary. To the NE of the study area, NE-trending 151 NEW EMPLACEMENT MODEL FOR KULA VOLCANICS LATEST MIOCENE ? - PLIOCENE extension + uplift S 2 2 N 1 1 M S P PLEISTOCENE RECENT degraded extension + uplift tiltedKulafaultblock alkalibasalt SİMAVGRABEN ALAŞEHİRGRABEN volcanism ex Alaşehirfootwall Simavfootwall ? magmachamber Figure 5. An alternative model for the latest Miocene—Pliocene to recent structural development of the Kula area (Sava(cid:223)(cid:141)(cid:221)n et al.1999). 1— master share plane (MSP), reactivated older weakness zone; 2— tension fracture as the product of regional updoming, or reactivated older strike-slip fault along with regional updoming; ex— prominent exhumation in the north. faults also cut the first-period plateau basalts of Kula dominant in character while all of the older volcanic series (Figure 7). of western Anatolia are generally K-dominant rocks. The Kula volcanic field is a rectangular area about 15 km N—S by 40 km E—W. The volcanic rocks consist of Volcanics of Kula lavas and tephra originating from ~ 80 small cinder cones In western Anatolia, during three distinct phases, the (Richardson-Bunbury 1996). volcanism changed from orogenic to K-alkaline and finally Basaltic cinder cones are commonly small compared to to sodic alkaline (Pliocene to Quaternary Kula volcanics; other types of volcanic edifices, e.g., they are orders of Richardson-Bunbury 1996). As the youngest volcanic magnitude smaller than those of the Andes (Bunbury rocks of western Anatolia, the Kula volcanics are Na- 152 M. TOK(cid:130)AER ETAL. e e) n n o o st st d d u u basalt one,m one,m rocks Pliocene-Quaternary UpperNeogeneunit(pebblestone,sandstandlimestone) LowerNeogeneunit(pebblestone,sandst olistostromeunit listwaeniteunit Menderescrystalline ort) (b). p e r d e h s bli u p n u a ( y a K d n a a) 2) ( 9 9 1 m051 053> 002> 003>> y ( r b bu n u B m o r s f n o r Quaternarysediment B4Quaternarybasalt B3Quaternarybasalt B2Quaternarybasalt Neogenesediments MenderesMassifmetamorphicbasement ctions from Kula and envi e s r a 65 C mn Alluviumunconformity 2,34,5,627,27B,28171 244,5,6B62,63,23 8,9,10,1120732 47,47B,47Karaoba33,34,351948,49,51Palankaya52,533250tongue56,355954 CiftÝbrahim 57,5873,7475unconformityredNeogenesedimentslacustrinelimestonefluviatileconglomerate arbleschistophiolitesequence :numberofcones ure 6.Two generalized stratigraphic colu a 1 m 2,3 Fig 153 NEW EMPLACEMENT MODEL FOR KULA VOLCANICS Explanations N Tibv QTTkhhvyy1 y Qa alluvium ar n Qkv1 er Burgazvolcanics at Qkv1 u Q Qkv1 Qat Asartepeformation Pzse Tiu unconformity Qat Tiu Ulubeyformation Qa e n e Qkv1 oc Tibv Beydağvolcanics Pli Tiah Ahmetlerformation e unconformity n Qkv1 m e Hachallar Pzse Qat Kv oc Thy Yenikoyformation Tiah usMi unconformity o Tiu e ac Kvm Vezirlermelange Qat Tiu Tiu Cretzoic unconformity o ae Pzse Esmeformation al P 0 1 2 3km strike-slipfault probablefault Figure 7. Reactivation of older NE-trending faults (modified from MTA map of the Kula area). Explanation from the MTA map (not our own). 1992). The diminutive size of the Kula cinder cones is (plateau or hilltop) around which flowing later the probably a result of a very low flow rate of magma to the younger lavas(cid:213) (Hamilton & Strickland 1841). The surface (Richardson-Bunbury 1996). geological map of Kula made by Hamilton & Strickland (1841) clearly illustrates the important role of NE—SW- Basaltic eruption in the Kula area started 1.6 Ma ago and WNW—ESE-trending lineaments in the development (Richardson-Bunbury 1996) and continued up to the of the cinder cones and on lava flow directions. According recent. These volcanics developed in more than three to those authors, the development of the Kula volcanics phases, or perhaps their evolution was without hiatus. occured in three periods: (1) plateau basalts with more Age determinations of the Kula lavas gleaned from than one flow, (2) subsequent erosional valleys and various publications (and also from different periods) are eroded cinder cones with vegetation, (3) fresh non- illustrated in Figure 8. eroded cinder cone without vegetation. The important tectonic, stratigraphic and Philippson (1914) confirmed this classification with sedimentological characteristics of the Kula volcanics some remarks. According to him, the time interval were reported previously by Hamilton & Strickland between the second and third periods was not short. (1841). According to those authors, topographic Rather, it was long, and there were also cinder-cone inversion of the basalt stratigraphy is widespread in the phases between the second and third periods. Kula area. (cid:212)It occurs where lava flows onto a plain, or into a valley of material more easily eroded than the basalt. Canet & Jaoul (1946) remarked that the cinder cones Following erosion the flow leaves as a topographic height in the area are situated along two straight lines whose 154

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Key Words: western Anatolia, extensional tectonics, Kula volcanics, . after NASA data base (from http://sideshow.jpl.nasa.gov/mbh/series.html); (b).
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