Turkish Journal of Earth Sciences (Turkish J. Earth Sci.), Vol. 11, 2002, pp. 1-13. Copyright ©TÜB‹TAK
Geology of the Ören and Surrounding Areas, SW Anatolia
ÖMER FEYZ‹ GÜRER1 & YÜCEL YILMAZ2
1 University of Kocaeli, Engineering Faculty, Department of Geological Engineering, Vinsan, TR-41100 Kocaeli - TURKEY (e-mail: [email protected]) 2 ‹stanbul Technical University, Faculty of Mines, Department of Geological Engineering, Maslak, TR-80626 ‹stanbul - TURKEY
Abstract: On the Lycian Nappes of SW Anatolia, Neogene basins developed along two different trends in different periods. NNE–trending basins formed during the Early-Middle Miocene period as exemplified by the Ören and Yata¤an grabens. These graben fills consist of three distinct rock units. At the base are (1) coarse clastics, sourced from elevated areas adjacent to the basin-bounding faults. These are linear river-valley fills. They give way upward to (2) alternating coal-bearing sandstone and limestone as the graben valleys were gradually widened, and the surrounding mountains were reduced by erosion. Finally, lake environment formed, invading the region during the advanced stage of graben development. In the lakes were deposited (3) extensive marls and limestones. The lake deposits gradually onlapped the graben shoulders. The NE–trending grabens extend SW toward the shore of the SW-NE–trending Kale-Tavas basin. The lake and the sea basin were apparently connected as evidenced by several marine incursions from the south into the Ören basin. The marine units wedge out to the north. On the graben shoulders, the Lower-Middle Miocene sediments were overlain unconformably by red, brown coarse clastic sediments as linear and axial fluvial deposits during Late Miocene time when N-S extensional tectonics began. Under this tectonic regime, some of the N-S–trending faults were reactived as oblique-slip faults with a dip-slip component. Later, the fluvial deposits were replaced by sediments of a new lake environment, in which extensive lacustrine limestones were deposited. The extents of the lakes were regional, stretching far beyond the limits of the grabens. The E-W–trending faults bordering the northern margin of the Gökova graben cut and postdate the Upper Miocene-Lower Pliocene lacustrine units. The Lower to Upper Miocene sequences were elevated on the graben shoulders. Along the northern edge of Gökova graben, more than 400 m of coarse fluvial conglomerates and debris were formed in front of this elevated region. The Gökova graben, mostly offshore, is about 150-km- long and enlarges westward from 5 to 30 km. The western margin of the graben rises steeply to over 1000 m, but the southern margin is less marked. The coastline has many bays and small offshore islands.
Key Words: Ören, Gökova, Neogene basin, extensional tectonics
Ören ve Çevresinin Jeolojisi, Güneybat› Anadolu
Özet: Güneybat› Anadolu’da, Likya Naplar› üzerinde iki farkl› zamanda ve iki farkl› yönde Neojen havzalar› geliflmifltir. KKD gidiflli, Ören ve Yata¤an havzalar› Erken-Orta Miyosen döneminde geliflmifltir. Bu grabenlerde üç farkl› kaya toplulu¤u vard›r; tabanda fayl› havza s›n›r›na komflu alanlardan derlenmifl kaba klastikler yer al›r. Bunlar çizgisel akarsu vadi dolgular›d›r. Bu çökeller, graben vadisinin giderek genifllemesi ve çevre yükseltilerin erozyonla afl›nd›r›lmas› ile kömür ara katk›lar› içeren kumtafl›, silttafl› ardalanmas›na geçer. Graben gelifliminin ileri evresinde göl ortam› oluflmufl ve bölgeyi kaplam›flt›r. Göllerde bafll›ca kireçtafl› ve marn çökelmifltir. Göl çökelleri tedrici olarak graben omuzlar›n› aflm›flt›r. KD yönlü grabenler, GB-KD yönlü Kale-Tavas havzas›n›n GB k›y›s›na do¤ru genifllemifltir. Göl ve denizel havzalar, Ören havzas›n›n güneyinde denizin bu graben içine do¤ru birkaç kez ilerlemesi ile k›smen birleflmifltir. Bu alanda denizel birimler kuzeye do¤ru kamalanmaktad›r. Kahverengi-bej renkli, kömür arakatmanl› gölsel ince detritikler ve marnlar temel üzerinde uyumsuzlukla çökelmifltir. Graben omuzlar›nda, Alt-Orta Miyosen çökelleri üzerine, Geç Miyosen’de, K-G gerilmeli tektonikle bafllayan lineer ve aksiyal fluviyal ortamda, k›rm›z›, kahve renkli klastikler çökelmifltir. Bu tektonik rejim ile K-G yönlü faylardan baz›lar›, e¤im at›m bileflenleri olan oblik faylar fleklinde yeniden hareket geçirmifltir. Daha sonra, fluvial birimler yerlerini yeni bir gölün kireçtafllar›na b›rakm›flt›r. Gölün yay›l›m› bölgesel olup K-G grabenlerin s›n›rlar›n› aflm›flt›r. Gökova grabeninin kuzey kenar›n› s›n›rlayan D-B do¤rultulu faylar, Üst Miyosen-Alt Pliyosen gölsel çökellerini kesmektedir. Alt ve Üst Miyosen istifleri graben omuzlar›nda yükselmifltir. Gökova grabeninin kuzey kenar› boyunca, yükselen blo¤un önünde, 400 metre’den daha kal›n iri akarsu çak›ltafllar› ve moloz birikmifltir. Gökova grabeni, büyük bölümü deniz içinde, 150 km uzunlu¤unda ve bat›ya do¤ru 5 km’den 30 km’ye kadar geniflleyen bir grabendir. Grabenin kuzey kenar›nda, bat› ucu 1000 m’yi aflan yükseltilere ulaflmaktad›r. Güney kenar›nda ise, bir çok küçük koy ve adalar›n olufltu¤u, daha az belirgin bir morfoloji ve k›y› çizgisi geliflmifltir.
Anahtar Sözcükler: Ören, Gökova grabeni, Neojen havzas›, gerilmeli tektonik
1 GEOLOGY OF ÖREN AND SURROUNDING AREAS (SW ANATOLIA)
Introduction al. 1999, Bozkurt 2000; Sar›ca 2000). The proposed There is a controversy concerning the age of development synthesis of previously available data (fiengör et al. 1985; of the E-W–trending graben basins of western Anatolia Walcott 1988) or (commonly) of inadequate data was (Figure 1). The two main views are: (1) the E-W grabens mostly obtained from the rocks cropping out along the began to form during the Late Oligocene-Early Miocene, immediate borders of the grabens (Seyito¤lu & Scott and have been continuously evolving ever since (Seyito¤lu 1992, 1996; Cohen et al. 1995). To test and compare & Scott 1991); and (2) the E-W grabens are rather young the two models, we undertook a field-mapping project to tectonic features, and began to form in Late Miocene time study the Ören area (Figure 2) because there and in the (McKenzie 1972; fiengör & Y›lmaz 1981; Mercier et al. surrounding regions, morphologically active and distinct 1989; Paton 1992; Y›lmaz et al. 1997, 2000; Koçyi¤it et young faults of various trends, together with thick
Gulf of Edre IA
39° BEG
N
Ý GDG
38° BH
A Massif BMG D
KT Menderes
37° M YG ÖG
AEGEAN SEA Kos Gulf of Gökova
L.N.F.
(L.N.) TAURIDES
02040 km Thrust 36° Normal and 27 strike-slip faults 29 30
mainly ophiolite, Tauride tectonic Neogene to recent mélange Cretaceous unit sedimentary rocks
Cretaceous flysch and Jurassic to Cretaceous Neogene volcanic olistostrome assoc. Limestone and detrital rocks rocks (Bornova flysch zone) metamorphic rocks of Menderes Massif granitic plutons
Figure 1. Geological map of western Anatolia (modified from Y›lmaz et al. 2000). BEG– Bergama graben; GDG– Gediz graben, BMG– Büyük Menderes graben; KT– Kale-Tavas basin, LN– Lycian Nappes; LNF– Lycian Nappe front; BH– Bozda¤ horst; ÖG– Ören graben; YG– Yata¤an graben. A, D, I and M are cities of Ayd›n, Denizli, ‹zmir and Mu¤la, respectively. Inset shows the location of the study area.
2 Ö. F. GÜRER & Y. YILMAZ B’ SE A’ E 8km
Kuyucak +
4
+ _ Scale No scale 0 W A NW B
Akbük bay
Lycian Nappes
+ _ lluvium a Gökova fm Turgut fm Yatagan fm Gökbel cong. Akbük ls Sekköy fm
Denizcik ls Gökçeören fm
and Tauride tectonic unit + _ 2000) and associated cross sections. MS– measured stratigraphic section (Figure 4), A– Alakilise.
et al. A E.-M. MIOCENE MS MESOZOIC
PALEOZOIC L. MIOCENE
E. PLIOCENE
E. MIOCENE . OLIGOCENE B’ QUATERNARY + L _ Pýnarören Ören B N GULF OF GÖKOVA
_+
Bayýrköy
_ + A’
_ _
+
+_
_ Bozalan +
+ _ A
Simplified geological map of the Ören graben (modified from Y›lmaz
Milas _
+
_ Söðütcük + Alaçam Figure 2.
3 GEOLOGY OF ÖREN AND SURROUNDING AREAS (SW ANATOLIA)
Neogene successions, are present. In this paper, the new direction. Grain size decreases toward the north, where data resulting from this study are first presented and the red clastic sediments pass laterally and vertically into then the data are discussed to shed light on the geological grey conglomerates, which in turn, pass vertically and evolution of these Neogene basins. laterally into grey, well-sorted sandstones with some The Gökova graben is one of the major E-W–trending limestones lenses. Locally these pass laterally into grey grabens of western Anatolia. (Figure 2). The Ören area is shales containing lignite beds. These shales are lagoonal located to the north of the Gökova graben where there and shallow-marine clastic sediments which contain are large Neogene outcrops. This Neogene is commonly gastropods, bivalves and benthic foraminifers of Late referred to as the Ören basin, which extends from the Oligocene-Early Miocene age (Becker-Platen 1970; Gulf of Gökova in the south to Milas in the north (Figure Koçyi¤it 1984; Hakyemez 1989; Akgün & Sözbilir 2). The Ören Neogene basin is bounded, for the most 2001). The sandstones are overlain by a flysch-like part, by steeply dipping oblique-slip faults with sequence, composed mainly of alternating sandstones and considerable amount of normal slip component. marls. This sequence has numerous fluvial channel deposits, ranging in thickness from a few meters to a few tens of meters; these were emplaced as turbidite deposits Geology of the Basins which incised the underlying soft sediments and also In the Gökova region, basins of various ages and disturbed their original attitudes. Therefore, locally orientations have been identified. The oldest basin, the developed unconformities were formed in the succession. Kale-Tavas molasse basin of fiengör & Y›lmaz (1981), is Upward in the section, the high energy of the depositional orientated ENE-WSW. The youngest basin is the modern environment decreases, as evidenced by fining-upward Gökova graben. Between the development of these profiles, and eventually the clastic sediments are gradually approximately ENE-WSW or E-W basins, roughly replaced by limestones of the Kale formation. Fauna from N-S–trending basins formed during the Early Miocene the limestones yield Aquitanian-Burdigalian ages and Late Miocene. The major geological characteristics (Hakyemez 1989; Görür et al. 1995; Akgün & Sözbilir of these basins are briefly described below. 2001).
The Kale-Tavas Basin The Ören Basin The Kale-Tavas is the oldest basin of the region, and its The Ören and Yata¤an basins are subparallel basins sedimentary fill ranges from Upper Oligocene to Lower trending approximately NNW-SSE (Figures 1 and 2). Miocene. The fill of the Kale-Tavas basin is best-observed These basins display identical strata of Early to Middle in the area that extends from northeast of Denizli in the Miocene age. Typically, the basin units rest east to the Gökova graben in the west (Figure 2). unconformably on the slightly metamorphosed rocks of the western Taurides. In places, the lowermost clastic The Kale-Tavas basin units rest on the Lycian Nappes rocks rest unconformably on the fossiliferous marine along an angular unconformity. The lowermost unit of limestones of the Kale-Tavas basin. Development of the the basin is a red, thick, massive to poorly-bedded and Ören and Yata¤an basins was controlled by oblique-slip poorly-sorted coarse conglomerate assigned to the fault systems, having major dip-slip components coupled Gökçeören formation. This conglomerate unit is devoid of with a subordinate dextral strike-slip component. The fossils, and is composed predominantly of ophiolitic basin sediments and their substrate are disrupted by E- materials derived from the underlying ophiolite, which W–trending normal faults around the Gulf of Gökova. forms the uppermost tectonic slice of the Lycian Nappes. These materials, which were accumulated to the north of The Ören basin fill consists mainly of two rock units an approximately NE-SW–trending fault zone, are mainly (Figure 3). The lower unit is composed predominantly of debris flow and fluvial deposits, sourced from these fault- clastic rocks of the Gökbel conglomerate. This unit is a induced structural highs. Clast imbrication indicates an massive to poorly bedded and poorly sorted grey, coarse approximately southeast to northwest palaeocurrent conglomerate with well-rounded clasts derived from the
4 Ö. F. GÜRER & Y. YILMAZ
Alluvium conglomerate, sandstone
Gökova fm fill Gökova graben QUATERNARY unconformity Denizcik lms limestone, marl 75m
Yataðan fm
continental red beds Bozdogan
100m Karacasu-
graben fill
E. PLIOCENE L. MIOCENE- unconformity
Sekköy fm Sekköy fm limestone, marl 150-200m
75 m
Turgut fm tuffite 100-1100 m 250m
lignite beds Ören graben fill
sandstone, siltstone EARLY - MIDDLE MIOCENE Gökbel cong. coarse conglomerate unconformity Akbük ls
Akçay grb. 2000 m Kale-Tavas basin fill shallow marine Gökçeören fm conglomerate, sandstone
LATE 50-400 m >400 m
OLIGOCENE unconformity Lycian Nappes ophiolite, and sedimentary rocks
Tauride tectonic unit recrystallised limestone,
phyllite Basement
MESOZOIC PALEOZOIC
Figure 3. Generalized stratigraphic section of the Milas-Ören area.
5 GEOLOGY OF ÖREN AND SURROUNDING AREAS (SW ANATOLIA)
underlying recrystallized limestones and phyllites. The forming the Gulf of Gökova. The northern margin is conglomerates are of debris flow and fluvial origin. bounded by a linear mountain front, which rises steeply Upward in the succession, the coarse conglomerates are to >1000-m. E-W–trending listric normal faults, together replaced by sandstones of the Turgut formation. The with a set of N60º-80ºE–trending oblique-slip faults, upper unit is a shale-marl-dominated, fine clastic characterise the northern margin. The E-W–striking succession having a number of lignite beds. The top of the faults commonly cut and offset the oblique-slip faults. sequence is a white marl and limestone unit called the The southern margin of the graben is topographically less Sekköy formation (Atalay 1980). steep and marked by many bays and small offshore The NW-SE–trending basin fills are composed islands. generally of sediments deposited in a continental The graben-bounding faults of the Gökova graben environment. Toward the south where the ENE- have apparently controlled deposition of a thick post- WSW–trending, partly coeval, marine Kale-Tavas basin Miocene-Pliocene sedimentary sequence which constitutes was located, a number of marine incursions into the N-S the Gökova Formation. The E-W faults cut the N- troughs occurred intermittently, as evidenced by the S–trending graben bounding faults and the rock groups presence of marine-fossil-bearing sandstone layers of the Miocene grabens. The sediments, deposited along interbedded with the lacustrine sediments (Figure 4). The the margin of the Gökova graben, consist of coarse clastic marine beds wedge out toward the north. The age of sediments, formed as scree deposits, unconsolidated these rock units has been variously assigned to the slope debris and lateral fan deposits. Their source is Aquitanian (Tchihatcheff 1869), the Aquitanian- undoubtedly the uplifted horst block lying in the Burdigalian (Nebert 1957), or the Oligocene-Lower immediate vicinity. The graben fill is rotated gently (10°- Miocene (Erentöz & Öztemur 1964). 15º) northward due to rotation on the major E- The lacustrine limestone is overlain unconformably by W–trending, south-dipping listric faults. The age of the a 100- to 200-m-thick, brown to red continental unconsolidated sediments in the graben may be inferred conglomerate and sandstone unit, the Yata¤an to be post-Pliocene from stratigraphic evidence, insofar Formation. In places, the red clastic sediments rest as debris from rocks of Late Miocene-Early Pliocene age directly on the Lycian Nappes. The red beds yield a rich sourced from the adjacent horst blocks have been mammalian fauna that ranges in age from Middle incorporated into the present graben fill. Astracian to Turolian in the Mu¤la region (Atalay 1980). The Yata¤an formation is composed of fluvial and debris- Geological Evolution flow deposits, laid down within fault-bounded, approximately N-S–trending troughs. At top of the In the light of the data presented above the major stages sequence is white lacustrine limestone of the Denizcik of the geological evolution of this region may be formation. The limestones are not confined to the limits summarised as follows. of the fault-controlled depressions where the clastic rocks accumulated; they cover a vast region as a capping First Stage limestone that extended from the gulf areas in the west to the Denizli area in the east. This distribution indicates The first stage corresponds to the period when the Lycian that the N-S graben depressions were filled and lost their Nappes, as a nappe package, consisting of slices of the topographic expression before deposition of the western Taurus metamorphic basement and the overlying limestones. Mesozoic platform carbonates, together with the dismembered ophiolites that form the uppermost nappe, travelled southward during Early Miocene time. The The Gökova Graben nappes were finally emplaced onto the Lower Miocene This is the southernmost graben of western Anatolia. It is basin fill of the Antalya basin before the Late Miocene 150-km-long, and widens westward from 5 to more than time (Figure 5) (Robertson 2000). 30 km (Figure 1). A major part of the graben is offshore,
6 Ö. F. GÜRER & Y. YILMAZ
LITHOLOGY FOSSIL CONTENT
AGE
FORM.
THICK.
conglomerate
PLIOCENE Gökova fm unconformity
marl 75 m
LANGIAN sandstone Sekköy fm
TORTONIAN
Monodonta (Osilinus) cf. Elegans FAUJAS fosilliferous Turritella crossei sandstone DA COSTA Turritella (Haustator) sp. aff. Terrebralia bidentata (DEFRANCE) 150-200 m Tympanotonus margaritaceous
BURDIGALIAN (BROCCHI) Potamides girondicus marl, (MAYER) Pirenella plicata coal beds Turgut fm (BRUGUIERE) Rostellaria dentata fosilliferous GRATELOUP sandstone Galeodes lainei (BASTEROT)
Arca (Anadora) cf. Montensis 200 m sandstone, MAYER siltstone, limestone Cardita sp,
AQUATANIAN Cerithium sp, conglomerate unconformity
recrystallised
unit limestone, dolomite
Tauride tectonic
MESOZOIC
Figure 4. Measured stratigraphic section of the Turgut and Sekköy formation (in the north of Alakilise town) (Modified from Nebert 1957)
7 GEOLOGY OF ÖREN AND SURROUNDING AREAS (SW ANATOLIA)
NS
KALE-TAVAS BASIN LYCIANLYCIAN NAPPES NAPPE
NAPPE
MENDERES MASSIF Oligocene
Figure 5. Pre-extension stage and development of the Kale-Tavas basin. The Lycian Nappes were moving south while a piggy-back basin, the Kale- Tavas basin, developed above the Lycian Nappes during Oligocene time. The listric normal faults controlled the southern edge of the basin, and the consequent coarse clastic deposition.
The Kale-Tavas basin began to form during this The E-W Extension Stage period. Within this basin, sediment deposition started The earlier stage of the N-S extension. N-S extension during the Late Oligocene, indicating that this graben began during Late Miocene time. During this period the E- began to form slightly earlier than the N-S grabens. W–trending Bozda¤ horst, located in the middle of the Mostly ophiolite-derived, coarse clastic materials at the Menderes Massif, was elevated (Y›lmaz et al. 2000). Low- base of the Kale-Tavas basin were sourced from a angle detachment faults are recognised along both the structural high formed from the Lycian Nappes. The high southern and northern flanks of the Bozda¤ horst. The was located to the south of the basin. The southern detachment faults appear to have been active mainly margin of the basin, bounded by this structural high was during Late Miocene time (Hetzel et al. 1995; Emre characterised by NE-SW–trending normal faults. For this 1996; Koçyi¤it et al. 1999; Y›lmaz et al. 2000; Bozkurt reason, the Kale-Tavas basin, which was situated above 2001; Sözbilir 2001) in that the Upper Miocene fluvial the contemporaneously southerly advancing Lycian Nappe lateral fan deposits derived from the horst were package, may be regarded as a piggy-back basin (Y›lmaz transported into the surrounding low topography as et al. 2000). coarse clastic marial. Away from the structural high the The N-S trending Ören and Yata¤an grabens, that are clastic rocks gave way gradually to lacustrine limestones. generally bounded by the oblique-slip faults, possibly This situation suggests that the horst was possibly developed in a N-S compressional stress field (Figure 6) surrounded by interconnected lake basins (Figure 7). in that the southern as well as the northern parts of Farther away from the horst, to both the south and western Anatolia suffered N-S compressional deformation north, approximately N-S–trending accommodation faults during this period (Y›lmaz & Polat 1998; Y›lmaz et al. began to develop on the upper plates of the detachment 2000; Robertson 2000) faults. These grabens were long, narrow troughs bounded by the oblique-slip faults which controlled the
8 Ö. F. GÜRER & Y. YILMAZ
N S
LYCIAN NAPPE
YATAGAN GRABEN
ÖREN GRABEN
Early-Middle Miocene
Figure 6. Differential stretching within the piggy-back basin areas formed N-S–trending faults and narrow grabens.
N S BOZDAG HORST KARACASU GRABEN
YATAÐAN GRB
ÖREN GRB.
Late Miocene
Figure 7. During the Late Miocene, N-S extension began. The Bozda¤ horst was elevated and major breakaway faults were formed. Above the detachment surfaces, approximately N-S–trending grabens began to form as cross-grabens.
9 GEOLOGY OF ÖREN AND SURROUNDING AREAS (SW ANATOLIA)
deposition of Upper Miocene sediments. Some of these have a sharp boundary with a steep slope of the newly faults appear to have been spatially associated with the developed graben valleys (Figure 9) (Y›lmaz et al. 2000). Early Miocene basin-bounding fault system, an example The present morphology of the region formed later, of this being the Ören graben. during the development of a set of E-W–trending faults in Finally, a new lake developed during Late Miocene- Quaternary time (Figure 10). Early Pliocene time. This new lake basin covered the entire northern area and extended into present offshore areas (Figure 8). Conclusions Structures and sediments in the northern Gökova region suggest different episodes of basin development. The interruption stage of the N-S extension . N-S extension appears to have been interrupted at the end of 1. The E-W–trending Kale-Tavas basin began to form Late Miocene-Early Pliocene period when a regionwide, during Oligocene time above the low-relief erosional surface formed on rocks as young as contemporaneously southerly-transported Lycian Early Pliocene. The limestones and red clastic rock of Late Nappe package, as a piggy-back basin. Miocene-Early Pliocene age, flat or tilted, were eroded 2. The N-S–trending Ören basin formed slightly later and lie below this surface. during Early Miocene time, under an E-W extension, N-S compression. The Ören and Kale- Tavas basins were interconnected. The later stage of the north-south extension. Following the development of the erosional surface, N-S 3. A new group of basins developed along reactivated extension was reactivated and the E-W–trending grabens NNW-SSE–trending faults during Late Miocene began to form. As a result, the erosional surface, as well time when N-S extension began, and possibly as the older structures and the Miocene-Lower Pliocene survived into Early Pliocene time. The basins were strata, were cut by faults that bound the east-west filled and lost their morphological expression at grabens. The low-relief erosional surfaces on the plateaux the end of Late Miocene time.
N S Denizli
BOZDAG HORST
Aydýn
MENDERES MASSIF
Early Pliocene
Figure 8. A new lake was developed during latest Miocene-Early Pliocene time, and it gradually invaded the flanks of the previously elevated Bozda¤ horst.
10 Ö. F. GÜRER & Y. YILMAZ
THE LATER STAGE OF N-S EXTENSION N Buldan S Denizli
BABADAG-HONAZ HORST BOZDAG HORST BÜYÜK MENDERES GRABEN
GÖKOVA GRABEN
YATAGAN GRABEN
ÖREN GRABEN
Late Pliocene
Figure 9. Following the development of erosional surface, the N-S extension was reactivated and the E-W grabens began to form.
W E
ÖREN GRABEN
GÖKOVA GRABEN
Quaternary
Figure 10. Present morphology of the Gökova region formed along E-W–trending faults possibly during Quaternary time. Then newly formed E-W–trending normal faults have localized the width of the shallow depressions into the present graben valleys.
11 GEOLOGY OF ÖREN AND SURROUNDING AREAS (SW ANATOLIA)
4. The modern Gökova graben developed later along Acknowledgements E-W–trending normal faults which cut and We would like to thank anonymous reviewers for their truncate the older units and their associated constructive comments that improved the earlier version structures. of the text. Steven K. Mittwede helped with the English.
References
AKGÜN, F. & S ÖZB‹L‹R, H. 2001. A palynostratigraphic approach to the KOÇY‹⁄‹T, A., Y USUFO⁄LU, H. & B OZKURT, E. 1999. Evidence from the SW Anatolian molasse basin: Kale-Tavas molasse and Denizli Gediz graben for episodic two-stage extension in western Turkey. molasse. Geodinamica Acta 14, 71-93 Journal of Geological Society, London 156, 605-616.
ATALAY, Z. 1980. Mu¤la-Yata¤an ve yak›n dolay› karasal Neojeninin MCKENZIE, D.P. 1972. Active tectonics of the Mediterranean region. stratigrafi araflt›rmas›. Geological Society of Turkey Bulletin 23, Geophysical Journal of the Royal Astronomical Society 30, 109- 93-99 [in Turkish with English abstract]. 185.
BECKER-PLATEN, J.D. 1970. Lithostratigraphische Untersuchungen im MERCIER, J.L., S OREL, D. & V ERGELY, P. 1989. Extensional tectonic Känozoikum Südwest-Anatoliens (Türkei). Beihefte zum regimes in the Aegean basins during the Cenozoic. Basin Research Geologischen Jahrbuch Heft 97, Hannover. 2, 49-71.
BOZKURT, E. 2000. Timing of extension on the Büyük Menderes Graben, NEBERT, K. 1957. Die braunkohlenvorkommen von Oeren . Mineral western Turkey, and its tectonic implications. In: B OZKURT, E., Research and Exploration Institute of Turkey (MTA) Report, No. WINCHESTER, J.A. & P IPER, J.D.A. (eds) Tectonics and Magmatism 3011, 21 p [unpublished]. in Turkey and the Surrounding Area . Geological Society, London, Paton, S. 1992. Active normal faulting, drainage patterns and Special Publications 173, 385-405. sedimentation in southwestern Turkey. Journal of the Geological BOZKURT, E. 2001. Late Alpine evolution of the central Menderes Massif, Society, London 149, 1031-1044 western Turkey. International Journal of Earth Sciences 89, 728- ROBERTSON, A.H.F. 2000. Mesozoic-Tertiary tectonic-sedimentary 744. evolution of a south Tethyan oceanic basin and its margins in COHEN, H.A., D ART, C.J., A KYÜZ, H.S. & B ARKA, A.A. 1995. Syn-rift southern Turkey. In: BOZKURT, E., WINCHESTER, J.A. & PIPER, J.D.A. sedimentation and structural development of the Gediz and Büyük (eds) Tectonics and Magmatism in Turkey and the Surrounding Menderes grabens, western Turkey. Journal of the Geological Area. Geological Society, London, Special Publications 173, 353- Society, London 152, 629-638. 384.
EMRE, T. 1996. Geology and tectonics of Gediz graben. Turkish Journal SAR›CA, N. 2000. The Plio-Pleistocene age of Büyük Menderes and Gediz of Earth Sciences 5, 171-185 [in Turkish with English abstract]. grabens and their tectonic significance on N-S extensional tectonics in West Anatolia: mammalian evidence from the ERENTÖZ, L. & ÖZTEMÜR, C. 1964. Aperçu général sur la stratigraphie du continental deposists. Geological Journal 35, 1-24. Néogéne de la Turquie et observations sur ses limites inférieures et supérieures, Institute ‘Lucas Maldada’ C.S.I.C. (Espana) SEY‹TO⁄LU, G. & S COTT, B. 1991. Late Cenozoic crustal extension and Cursilles Conferencias, Madrid 9, 259-266. basin Formation in west Turkey. Geological Magazine 128, 155- 166. GÖRÜR, N., fi ENGÖR, A.M.C., S AK›NÇ, M., T ÜYSÜZ, O., A KKÖK, R., Y ‹⁄‹TBAfl, E., OKTAY, F.Y., B ARKA, A.A., S AR›CA, N., E CEV‹TO⁄LU, B., D EM‹RBA⁄, SEY‹TO⁄LU, G. & S COTT, B.C. 1992. The age of Büyük Menderes Graben E., E RSOY, fi., A LGAN, O., G ÜNEYSU, C. & A KYOL, A. 1995. Rift (west Turkey) and its tectonic implications. Geological Magazine formation in the Gökova region, southwest Anatolia: implications 129, 239-242. for the opening of the Aegean Sea. Geological Magazine 132, SEY‹TO⁄LU, G. & SCOTT, B.C. 1996. The cause of N-S extensional tectonics 637-650. in western Turkey: tectonic escape vs back-arc spreading vs HAKYEMEZ, Y. 1989. Geology and stratigraphy of the Cenozoic orogenic collapse. Journal of Geodynamics 22, 145-153. sedimentary rocks in the Kale-Kurbal›k area. Denizli-southwestern fiENGÖR, A.M.C. & Y›LMAZ, Y. 1981. Tethyan evolution of Turkey: a plate Turkey. Mineral Research and Exploration Institute of Turkey tectonic approach. Tectonophysics 75, 181-241. (MTA) Bulletin 109, 1-14. fiENGÖR, A.M.C., GÖRÜR, N. & fi ARO⁄LU, F. 1985. Strike-slip faulting and HETZEL, R., R ING, U., A KAL, C. & T ROESCH, M. 1995. Miocene NNE- related basin Formation in zones of tectonic escape: Turkey as a directed extensional unroofing in the Menderes Massif, case study. In: BIDDLE, K. & C HRISTIE-BLICK, N. (eds) Strike-slip southwestern Turkey. Journal of the Geological Society, London Faulting and Basin Formation . Society of Economic 152, 639-654. Paleontologists and Mineralogists, Special Publication 37, 227- KOÇY‹⁄‹T, A. 1984. Güneybat› Turkiye ve yak›n dolay›nda levhaiçi yeni 264. tektonik geliflim. Geological Society of Turkey Bulletin 27, 1-16 [in Turkish with English abstract].
12 Ö. F. GÜRER & Y. YILMAZ
SÖZB‹L‹R, H. 2001. Geometry of macroscopic structures with their Y›LMAZ, Y., G ENÇ, fi.C., G ÜRER, Ö.F., B OZCU, M., Y› LMAZ, K., K ARAC›K, Z., relations to the extensional tectonics: Field evidence from the ALTUNKAYNAK, fi. & E LMAS, A. 2000. When did the Western Gediz Detachment, western Turkey. Turkish Journal of Earth Anatolian grabens begin to develop? In: BOZKURT, E., WINCHESTER, Sciences 10, 51-67. J.A. & PIPER, J.D.A. (eds) Tectonics and Magmatism in Turkey and the Surrounding Area. Geological Society, London, Special TCHIHATCHEFF, M. L. 1869. Asie Mineure Description Physique de cette contrée, 8, Geologie, Paris. Publications 173, 353-384. WALCOTT, C.R. 1988. The Alpine Evolution of Thessaly (NW Greece) and Y›LMAZ, Y. & P OLAT, A. 1998. Geology and evolution of the Thrace volcanics, Turkey. Acta Volcanologica 10, 293-303. Late Tertiary Aegean Kinematics. Geologic Ultraiectina. Mededelingen van de Faculteit Aardwetenschappen Universiteit Y›LMAZ, Y., GENÇ, fi.C., GÜRER, Ö.F., ELMAS, A., KARAC›K, Z., ALTUNKAYNAK, Ultrect 162, 176 p. fi. & G ÜLEÇ, N. 1997. Ayval›k-Dikili-Çandarl›-Bergama Aras›nda (Edremit-Bergama Grabenleri Çevresinde) Genç Ma¤matizman›n Jeolojik ve Petrolojik Araflt›r›lmas›. YDABÇAG-228/G, YDABÇAG- 420/G, Proje Raporu, 75 p [Turkish with English abstract, unpublished].
Received 26 February 2001; revised typescript accepted 19 October 2001
13