Abstract:A close relationship between formation of approximately upright folds with axes normal to the extension direction and ramp/flat extensional geometries is established for well exposed Neogene syn-extensional rocks on the presently low-angle Gediz detachment fault. along the southern margin of the Gediz Graben region of western Anatolia, Turkey. Three unconformity-bounded sedimentary sequences and several metamorphic extensional allochthons were mapped in the upper-plate of the Gediz detachment. The oldest sedim… Show more
“…Published work in the Aegean demonstrates the close spatial and temporal relationship among development of extensional detachment faults, ductile shear zones and granite emplacement (Verge, 1993; Bozkurt & Park, 1994; Hetzel et al . 1995 a , b ; Avigad, Baer & Heimann, 1998; Forster & Lister, 1999; Koçyiğit, Yusufoğlu & Bozkurt, 1999; Okay & Satır, 2000; Işık & Tekeli, 2001; Sözbilir, 2001, 2002; Pe-Piper, Piper & Matarangas, 2002; Bozkurt & Sözbilir, 2004; Işık, Tekeli & Seyitoğlu, 2004; Ring & Collins, 2005; Thomson & Ring, 2006). Figure 1.Tectonic map of the Aegean region showing tectonic units, major tectonic structures, metamorphic massifs, syntectonic granitoids and Neogene extension directions (structural data are from Lee & Lister, 1992; Hetzel et al .…”
Synextensional granitoids may have significant structural features leading to the understanding of the evolution of extended orogenic belts. One of the highly extended regions, the Aegean region, includes a number of metamorphic core complexes and synextensional granitoids that developed following the Alpine collisional events. The Alaçamdag area in northwestern Turkey is one of the key areas where Miocene granites crop out along the boundary of various tectonic units. Structural data from the Early Miocene Alaçamdag granites demonstrated two different deformation patterns that may provide insights into the development of granitic intrusions and metamorphic core complexes. (1) Steeply dipping ductile shear zones caused emplacement of syn-tectonic granite stocks; they include kinematic indicators of a sinistral top-to-the-SW displacement. This zone has also juxtaposed theİzmir-Ankara Zone and the Menderes Massif in the west and east, respectively. (2) Gently dipping ductile shear zones have developed within the granitic stocks that intruded the schists of the Menderes Massif on the structurally lower parts. Kinematic data from the foliated granites indicate a top-to-the-NE displacement, which can be correlated with the direction of the hangingwall movement documented from the Simav and Kazdag metamorphic core complexes. The gently dipping shear zones indicate the presence of a detachment fault between the Menderes Massif and the structurally overlyingİzmir-Ankara Zone. Mesoscopic-to map-scale folds in the shallow-dipping shear zones of the Alaçamdag area were interpreted to have been caused by coupling between NE-SW stretching and the accompanying NW-SE shortening of ductilely deformed crust during Early Miocene times. One of the NE-trending shear zones fed by granitic magmas was interpreted to form the northeastern part of a sinistral wrench corridor which caused differential stretching between the Cycladic and the Menderes massifs. This crustal-scale wrench corridor, theİzmir-Balıkesir transfer zone, may have controlled the asymmetrical and symmetrical extensions in the orogenic domains. The combination of the retreat of the Aegean subduction zone and the lateral slab segmentation leading to the sinistral oblique-slip tearing within the Eurasian upper plate appears to be a plausible mechanism for the development of such extensive NE-trending shear zones in the Aegean region.
“…Published work in the Aegean demonstrates the close spatial and temporal relationship among development of extensional detachment faults, ductile shear zones and granite emplacement (Verge, 1993; Bozkurt & Park, 1994; Hetzel et al . 1995 a , b ; Avigad, Baer & Heimann, 1998; Forster & Lister, 1999; Koçyiğit, Yusufoğlu & Bozkurt, 1999; Okay & Satır, 2000; Işık & Tekeli, 2001; Sözbilir, 2001, 2002; Pe-Piper, Piper & Matarangas, 2002; Bozkurt & Sözbilir, 2004; Işık, Tekeli & Seyitoğlu, 2004; Ring & Collins, 2005; Thomson & Ring, 2006). Figure 1.Tectonic map of the Aegean region showing tectonic units, major tectonic structures, metamorphic massifs, syntectonic granitoids and Neogene extension directions (structural data are from Lee & Lister, 1992; Hetzel et al .…”
Synextensional granitoids may have significant structural features leading to the understanding of the evolution of extended orogenic belts. One of the highly extended regions, the Aegean region, includes a number of metamorphic core complexes and synextensional granitoids that developed following the Alpine collisional events. The Alaçamdag area in northwestern Turkey is one of the key areas where Miocene granites crop out along the boundary of various tectonic units. Structural data from the Early Miocene Alaçamdag granites demonstrated two different deformation patterns that may provide insights into the development of granitic intrusions and metamorphic core complexes. (1) Steeply dipping ductile shear zones caused emplacement of syn-tectonic granite stocks; they include kinematic indicators of a sinistral top-to-the-SW displacement. This zone has also juxtaposed theİzmir-Ankara Zone and the Menderes Massif in the west and east, respectively. (2) Gently dipping ductile shear zones have developed within the granitic stocks that intruded the schists of the Menderes Massif on the structurally lower parts. Kinematic data from the foliated granites indicate a top-to-the-NE displacement, which can be correlated with the direction of the hangingwall movement documented from the Simav and Kazdag metamorphic core complexes. The gently dipping shear zones indicate the presence of a detachment fault between the Menderes Massif and the structurally overlyingİzmir-Ankara Zone. Mesoscopic-to map-scale folds in the shallow-dipping shear zones of the Alaçamdag area were interpreted to have been caused by coupling between NE-SW stretching and the accompanying NW-SE shortening of ductilely deformed crust during Early Miocene times. One of the NE-trending shear zones fed by granitic magmas was interpreted to form the northeastern part of a sinistral wrench corridor which caused differential stretching between the Cycladic and the Menderes massifs. This crustal-scale wrench corridor, theİzmir-Balıkesir transfer zone, may have controlled the asymmetrical and symmetrical extensions in the orogenic domains. The combination of the retreat of the Aegean subduction zone and the lateral slab segmentation leading to the sinistral oblique-slip tearing within the Eurasian upper plate appears to be a plausible mechanism for the development of such extensive NE-trending shear zones in the Aegean region.
“…The study area is located in the Alpine-Himalayan orogenic belt, and is a part of tectonically active zone with numerous fault lines (Sozbilir 2002). The major tectonic lines observed in the study area are the E−w directed graben faults with lengths ranging up to 100 km, which are cut by N−S directed secondary faults (Inci 1991;Suzen et al 2006).…”
Hidrogeologija in hidrokemija marmornega vodonosnika s ponornim točkovnim napaja njem (Masiv Meredes, zahodna Turčija) Masiv Menderes je območje metamorfnih kamnin v zahodni Anatoliji, Turčija. Razteza se v smeri SV-JZ in je sestavljeno predvsem iz regionalno metamorfiziranih sljudnih skrilavcev in marmorjev. Goro Bozdag sestavlja sistem manjših grud in tektonskih jarkov, orientiranih v smeri sever-jug. Masiv je delno zakrasel, s tipičnimi kraškimi oblikami, med katere spadata tudi polji Ayvacik in Subatan, ki se drenirata skozi istoimenske ponore. Obe polji sta razviti v prelomni coni orientirani v smeri sever-jug. Glavni namen opisane raziskave je določiti stopnjo zakraselosti območja in hidrokemične lastnosti vode, ki teče skozi marmornati masiv. Podrobne speleološke raziskave so pokazale, da je zakraselost močno pogojena z regionalno geološko strukturo, mineraloško sestavo marmorja in velikostjo dotokov v ponore. Izotopske analize tritija in sledenje podzemnih voda kažejo na hiter tok in povezavo med poljem Subatan in visoko mineraliziranimi izviri na jugu obravnavanega območja.
“…(2000) concluded that this formation was deposited within the NE- and NW-trending cross grabens, which developed as a result of N–S compression prior to development of the present E-trending Aegean graben system (Yılmaz et al . 2000), while some others such as Sözbilir (2002), Bozkurt & Sözbilir (2004), Purvis & Robertson (2004) and Çiftçi & Bozkurt (2009) advocated that the Soma Formation was deposited in a lake environment developed during the early stage of the E–W rifting in Western Anatolia. Based on pollen (Yalçınkaya & Afşar, 1980), ostracods (Akyürek & Soysal, 1983), mammal fossils (Bernor & Tobien, 1990) and mollusc fauna (Yeşilyurt & Taner, 1999), a Middle to Late Miocene age was assigned for the deposition of the Soma Formation.…”
Section: Geological Settings and Stratigraphymentioning
In this study, we show that the southern branch of the North Anatolian Fault has been active since Late Pliocene time and that evidence of activity is supported by geological and seismological data. The southern branch of the North Anatolian Fault consists of four segments from west to east: Yenice-Gönen, Manyas-Mustafakemalpaşa, Uluabat and Bursa. These faults delimit the Bursa-Gönen Depression, with the Bandırma-Mudanya Uplift to the north and Uludag-Sularya Uplift to the south. The Bursa-Gönen Depression includes Upper Pliocene to Recent sediments that thicken to the south, suggesting a deposition pattern under active fault control. Study of fault kinematics suggests that the Bursa-Gönen Depression started as a small pull-apart basin during Late Pliocene time, and then evolved to a large depression. The faults delimiting this depression are still active and capable of producing future earthquakes.
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