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A GEOLOGICAL STUDY IN THE KARABURUN PENINSULA Adnan KALAFATÇIOĞLU Mineral Research and Exploration Institute of Turkey ABSTRACT. — The oldest formations in the Karaburun Peninsula exposed to the effects of the Hersinian and Alpine orogenies, are conglomerates, graywackes, arkoses, sandstones, schists, quartzites and limestones. Lack of fossils in the Devonian system made it impossible to go into distinguishing further subdivisions. Lower Carboniferous limestones containing fossils overlie De- vonian series. Unlike in Sakız Island, where unconformities are occasionally observed, such is not the case in the Karaburun Peninsula. The Mesozoic starts by a conglomerate base laid upon the Paleozoic formations and as a rule contains sandstones and limestones. Although a few Upper Triassic fossils are encountered in it, the well-defined ones belong to the Jurassic system. Jurassic-Lower Cretaceous-Upper Cretaceous ensemble (including Turonian) presents a com- prehensive series in the form of massive and plated limestones. The Upper Cretaceous (Maestrich- tian) overlying this series also begins with a basal conglomerate and comprises pink limestones and sandstones overlain by grey and white compact schistose limestones showing good stratifica- tion. The youngest fossiliferous sediments in this area belong to the Miocene. Miocene systems composed of sandstones, clay, marls and limestones with intercalated tuff show that volcanism was on during the Neogene. In the course of this period rhyolitic, andesitic and basaltic lavas escaping from the cracks came up to cover older formations and a multitude of such cracks and faults came to be as a resultr of volcanic activities. After this introduction, the following may be pointed out regarding the local paleogeography and tectonic history. Paleozoic formations which came up above sea level due to the Hersinian folding went down again during the Upper Triassic (possibly Jurassic) and the sea lasted till the end of the Turonian epoch. Then in the course of the sub-Hersinian phase the area emerged from under the sea but transgressions in the Maestrichtian time caused it to sink once more below the sea level. The upper layers of the Maestrichtian show strong folding and small synclines and anticlines, indicating that the Alpine orogeny took place during the Late Cretaceous or some- what later and the Maestrichtian limestones were severely folded while they were not yet completely solidified. Folding, during the Mesozoic time, did not occur under unidirectional forces. Here, rather a set of multidirectional movements are observed. The Neogene sediments overlie older formations beginning with a red layer of conglomerate at the bottom. In the eastern part of our district there exists a basal conglomerate between Mio- cene and Pliocene formations. I. INTRODUCTION km away from Izmir and only 15 km The area under study is the 60 km from the Island of Sakız. Examination long Karaburun Peninsula and the vi- of rock samples and subsequent determi- cinity, extending N-S in the Western nations were taken up by Dr. P. de Anatolia, west of the vilayet of İzmir. Wijkerslooth, Dr. C. Kieft and Dr. Klaus The work was conducted to cover a Markus. Fossils were identified by Miss total of 1600 square kilometres, equally Sevinç Başad, Dr. C. Öztemür and Dr. divided between the map-sections No. Y. Ginkel. I feel indebted and owe many 86/1 and 86/3. The area is roughly 50 thanks to the gentlemen cited above, A GEOLOGICAL STUDY IN THE KARABURUN PENINSULA 41 and also to Dr. Cahit Erentöz for valu- able suggestions and to Prof Dr. İhsan Ketin who helped me during my field work. II. GEOGRAPHY Although not much elevated, this district, with its suddenly rising hills right along the shore line, gives the im- pression of a mountainous country. In the Peninsula, surrounded by plains at sea level and tectonic troughs, there are valleys encircled by mountains of lime- stones and andesites. Highest peaks are Akdağ (1212 m), Bölmece (848 m) and Kırdağ (707 m). While the northern part is dotted III. PREVIOUS STUDIES with hills, the Çeşme depression area forms a flat stretch of land. Morpholo- In 1911, A. Philippson (8) carried gically four groups may be distinguished out the geologic survey of the entire in the district : a) Devonian sandstones Peninsula, drew a geologic map of it and limestones, b) Mesozoic limestones, and correlated formations there with c) Neogene sediments and d) andesites those of Greece and the Island of Sakız. and basalts. Here we find high cliffs of According to Phillippson, limestone for- the Alpine character, difficult to cross, mations covering the higher parts as in the Mesozoic limestones, as well as well as wide flat are of Mesozoic age deep dry valleys and the like, in eroded and represented in two fades : a) the limestone formations. Vast area of the massive limestone facies and b) the Devonian age lying to the NW of the plated limestone facies, corresponding district has a monoclinal structure dip- ping west. The morphological structure to the Olonese limestones in Greece is built of Neogene sediments and tuffs. (they contain secondary intercalated In some places andesites form individu- schists). al hills void of vegetation. The area is In 1921 Ktenas conducted a survey usually dry during the summer and wet in northern section of the Peninsula to during the winter. It is drained mainly by streams of water such as Örendere, find the eastwardly continuation of the Söğütdere flowing due south and due formations in Sakız and pointed out the north and their tributaries. following groups of the Paleozoic : 42 Adnan KALAFATÇIOĞLU In 1939 Werner Paeckelmann (7) set outcrop in the northwestern part of the age of the limestones in the region the map-section 86/1 over a stretch of of Çeşme as being Triassic. area 20 km long and 10 km wide, con- Nuriye Pınar mentioned the exist- sisting mainly of schist, sandstone, arkose, enee of a great number of hot springs conglomerate, graywacke, quartzite and and mineral water sources within the grey limestone layers imbedded in schists depression area of Çeşme. and graywackes. This series is subdivided Mehmet Akartuna (1) claims that into several groups by Ktenas, ranging there is a discordance visible between up to the Upper Carboniferous. We the Miocene and Pliocene formations think this series should best be consider- just east of the Peninsula. ed of the Devonian age, without going into further subdividing. Because, inclu- IV. STRATIGRAPHY ded into the Middle and Upper Carbon- iferous, it underlies the fossiliferous A. Paleozoic Lower Cretaceous limestones, indicating Devonian. — Devonian formations continuous sedimentation. A GEOLOGICAL STUDY IN THE KARABURUN PENINSULA 43 Within this series, roughly 3000 m Middle Carboniferous, showing angular thick, neither fossils nor any sedimen- unconformity. While, to the south of tation gaps are encountered. Its relation Yelkentaş, in the Peninsula of Karabu- to the other Devonian formations may run graywackes and schists of the De- be summarized as follows : Although vonian age underlie Lower Carbonife- the under part of the Devonian sedi- rous limestone with fossils and without ments is not visible in the district, it is any sign of unconformity. At a typical a known fact that the semi-metamorphic section in the region of Örendere, of series of pre-Devonian age outcropping the northern part of the map-section in the Island of Spalmatori, to the west 86/1, is seen a basal conglomerate of of the Peninsula, here constitutes the the Mesozoic age overlying the Devonian lower parts of the Devonian deposition. series. Limestone banks are encountered The relation of this latter with the Lo- in the upper parts of this Devonian wer Carboniferous limestones overlying series and here, most probably, lime- it is not very clearly indicated. In the stones and sandstones grade into one Island of Sakız Devonian is overlain by another. Limestones estimated to belong 44 Adnan KALAFATÇIOĞLU to the Lower Carboniferous seem to be Glomospira eroded out and presently non existent. Tolypammina Whereas, a little to the south, portions Trepeilopsis of the limestones that escaped complete Hyperammina erosion are still visible. Globivalvulina Palaeotextularia Lower Carboniferous-— The grey, Endothyra compact, crystalline limestone beds seen- Plectogyra between Yelkentaş and Gerence to the east of the locality known as Ker- Fusulinidae : miyan Yalısı (map section 86/1) and Eostaffella those in Şifne Peninsula and to the Parastaffella south of it (map-section 86/3) belong to There exist other limestone areas in the Lower Carboniferous (Upper Visean our district that we might include into to Lower Namurian). We are likely to the Carboniferous, besides, and in addi- place white crystalline limestones under- tion to, the Lower Carboniferous ones lying the Devonian, north of the Kara as determined through fossils listed Island, among the Lower Carboniferous above. However, we could not do so formations. because a) No fossils were found and The following fossils (determined h) lithologic data alone is not sufficient by V. Ginkel) came from compact, crys- for exact age determination. Upper parts talline limestones found in the east of of the Carboniferous are not represented Kermiyan Yalısı (map-section 86/1) : in the Peninsula. And limestones for- merly known to belong to the Paleozoic Plectogyra are now marked down as Mesozoic. Eostaffella Climacammina B. Mesozoic Paramillerella (Eostaffella) Mesozoic rocks mainly occur in lime- Endothyra stone facies. The subject matter in this Bryozoa district is the comprehensive series possibly Corals beginning with the Upper Triassic and All of the fossils named above are continuing up into the Upper Creta- found in the white, compact semi-crys- ceous (Coniacian). It covers wide areas talline limestones of the Şifne Peninsula in the map-sections 86/1 and 86/3, and as well. The brown limestone beds over- stretches in the N-S direction forming lying the white, compact limestones con- a range of mountains marked with high tained Geinitzina (Lunucammina) of the hills.

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