SW Anatolia Research Articles

SOIL LIQUEFACTION HAZARD ASSESSMENT OF DALAMAN RESIDENTIAL AREA

The Phenomenon of Liquefaction gained importance after the 1964 Alaska and Niigata Earthquakes, and it has started to be studied worldwide. Türkiye, located in a very tectonically active zone, has been exposed to many devastating earthquakes. Dalaman is located in SW Anatolia which is under the control of active extensional tectonic regime that may generate such devastating earthquakes in the future. Moreover, because the Dalaman residential area is located on sedimentary deposits, determination of the liquefaction susceptibilities of the soils in the region is an important task to take essential precautions. Analyses have been performed according to two earthquake scenarios with magnitudes Mw=5.5 and Mw=7.5. Standard Penetration Test blow number-based simplified procedure has been used in the analyses and it has been seen that Dalaman residential area is highly susceptible to liquefaction. Most of the liquefiable soils are sands and they make the central part of the area. The northern part of the basin is formed of gravels and safer compared to the southern part, which is formed mostly of sands, silts and clays. Considering the population of the residential area approximately 40.000 people are under danger in case of a M=7.5 earthquake scenario.

Migration of Fupingopollenites in the Cenozoic: Contribution from Turkish palynoflora and paleoclimatic implications

Fupingopollenites, an extinct plant, has been suggested to belong to a family that originated in eastern Asia, where it was recovered from the early middle Eocene. It developed throughout the Oligocene in eastern Asia, expanding its geographical range and reaching maximum distribution and probably species diversity in the Miocene. In this study, we present the Fupingopollenites occurrences from different regions and ages in Türkiye: the middle-late Eocene transition from the Hatıldağ area (NW Türkiye), the middle-late Eocene transition from the Niğde-Ulukışla area (central Türkiye), the early Oligocene from the Ankara-Şereflikoçhisar area (central Türkiye), the Miocene from the Muğla area (SW Anatolia), and the Pliocene from the Isparta-Şarkikaraağaç area (southern Anatolia). Based on all new findings and published records, we suggest that the migratory route of this plant into Europe is across Türkiye. Furthermore, we can conclude that the suitable palaeoclimatic and palaeoenvironmental conditions for the flourishment of this pollen existed in Türkiye during the Eocene-early Oligocene. According to the numerical climatic estimates, the favorable mean annual temperature and the mean annual prepitation was ∼16 °C and 1000–1100 mm respectively. In addition, we suggest that the microclimatic conditions driven by the intense local tectonics in different depositional areas exerted a significant role in the distribution of this plant. In this study, the botanical relationship of Podocarpium podocarpum with Fupingopollenites has not been fully determined. However, it is noteworthy that both plants were identified in the macro- and micro-flora of Muğla and its surroundings in the Middle Miocene.

The upper crustal thermal structure of the Cameli Basin and its surroundings (SW Anatolia, Türkiye) by using the fractal-based centroid method of aeromagnetic data and its relationship with earthquakes occurring in the region

The Cameli Basin and its surroundings are located in southwestern Anatolia, Türkiye, and are one of the tectonically active regions in western Türkiye. The Curie point depth of continental crust can help us to determine the regional tectonic and geothermal structures. The aeromagnetic magnetic data of the study region were used to determine the Curie Point Depth estimates. The fractal-based centroid method is used for this purpose. The fractal approach removes the effect of fractal magnetization in the power spectrum. The depth to the bottom of the deepest magnetic sources in the study region ranges between 6.9 and 14.05. The estimated thermal gradient varies from 41.28°C/km to 89.23°C/km and the average value is 58.59°C/km (580°C for magnetite). The distributions of earthquakes are compatible with NW-SE trending estimated Curie depth anomalies. Interpretation indicates that the depth to the Curie isotherm is considerably shallower than the Moho depth.

From Hellenistic slipped tableware to Roman Imperial Sagalassos Red Slip Ware: A petrographic and geochemical study

This paper offers new insights from the petrographic and geochemical characterisation of 92 pottery samples from the archaeological site of Sagalassos in SW Anatolia (modern-day Turkey). The sampled table wares form part of the Hellenistic to Roman Imperial local pottery production lines. The aim of this study is to reconstruct in more detail the tableware production at the site and examine Sagalassos Red Slip Ware (SRSW) in comparison with the pre-existing Hellenistic tradition in slipped pottery. The results suggest that Hellenistic Colour Coated Ware (CCW) and Gray Ware with Black Slip (GWBS) were locally produced at the site using the same raw materials as the ones used for the subsequent mass-produced Sagalassos Red Slip Ware (SRSW), namely clays from the nearby NW parts of the valley of Çanaklı. SRSW appears thus as a continuation of the Hellenistic tradition in slipped pottery at Sagalassos, at least as far as some choices for clay raw materials are concerned. At the same time, this study provides for the first time evidence of regional production of a type of eastern sigillata that appears macroscopically similar to SRSW, while the number of identified imported wares to the polis of Sagalassos contributes new evidence to the discussion on the production of GWBS in the wider region of Anatolia and the origin of Eastern Sigillata A (ESA). Using the site of Sagalassos as a case-study, this research aims to demonstrate the importance of the analytical examination of pottery in a longue durée perspective in order to reconstruct ceramic traditions and better understand the local and regional sociocultural mechanisms behind them.

Dynamics and a Hydraulic-Soil Mechanical Model for Pockmarks in a Mud-draped Lake: Lake Sünnet (NW Anatolia)

The scarcity of bathymetric studies in most Turkish lakes does not allow the documentation and the potential causes of lake bottom irregularities. In this study, relatively high-resolution bathymetric data from Lake Sünnet (NW Anatolia) revealed five deep (5.7 to 9.2m) and narrow (10 to 20m) depressions located along the boundary between the lake bottom and the steep lake margins. Analysis of lake level data belonging to dry seasons hints no leakage through these depressions. However, the negative conical shape and weakly developed levees around the holes suggest an upward episodic groundwater discharge for which direct evidence has been absent up to date. A combined hydraulic and soil mechanical model successfully explains the pockmark activity due to the flow of water through conduits in karstic carbonate bedrock. According to sedimentation rates and average depth of pockmarks in Lake Sünnet, and available regional paleoclimate studies, the onset of pockmark activity might coincide with the transition from the Near East Aridification Phase to the humid Beyşehir Occupation Phase around 300 BCE in SW and NW Anatolia.

KAOLIN FORMATION IN YATAĞAN (MUĞLA) LIGNITE DEPOSIT

The 30-km-long and 10-km-wide, coal-bearing Yatağan Basin is located in SW Anatolia, close to the eastern coast of the Aegean Sea, Türkiye. The basement consists of Menderes Massif metamorphics in the NW part of this intermontane basin, c. 80-km2-large area (Turgut lignite deposit). The Neogene and Quaternary sedimentary filling comprises fluvioterrestrial, limnic and telmatic sediments which contain a mineable coal seam up to 15 m thick, unconformably overlain the basement. Two fresh and six weathered samples were picked up from the Menderes Massif gneiss outcrops of the catchment area. Eight sedimentary rocks, inorganics over and underlying the coal seam, were obtained from four borehole cores. All samples were examined under the optical microscope; XRD, SEM-EDX and ICP-MS analyses were later performed. This study aims to examine the mineralogical content and geochemical processes of the sedimentary rocks from different formations, namely Sekköy and Turgut Formations, which are over- and underlying the lignite horizon, to assess the clay mineral formations and transformations. Gneiss samples contain mainly quartz, plagioclase, K-feldspar, muscovite and biotite with a lesser amount of tourmaline, chlorite, garnet, apatite, zoisite, zircon and Fe-oxides. The -2 µm fraction consists mainly of illite, with fewer smectite and kaolinite. Sericitizitation of feldspar is the main product in gneisses. Coal over-and underlying sedimentary rock samples contain mainly quartz, plagioclase, K-feldspar, muscovite, and biotite with less pyrite and iron oxides. The -2 µm fraction of the sedimentary rock samples consists of variable clay mineral contents. Kaolin content is higher in acidic conditions with an opposite correlation to smectite occurrences. The geochemistry of Menderes Massif gneisses shows that it gave felsic material to the catchment area, whereas the geochemistry of sedimentary rocks is not coherent in all cases. Geochemical parameters like CIA and PIA proved that weathering processes of the source materials prevailed during the generation of these sedimentary units.

A Late Holocene climate reconstruction from the high-altitude Lake Gölcük sedimentary records, Isparta (SW Anatolia)

AbstractA high-resolution multiproxy lake sediment dataset, comprising lithology, radiography, μXRF elemental, magnetic susceptibility (MS), δ13C, and δ18O measurements since ca. AD 400 is presented in this study. Changes in lithology, radiography, magnetic susceptibility (MS), δ13C, and δ18O reflect wet/dry climate periods, whereas variability in log(Ca/K) can reflect warm/cold climate periods. Analyses of the multiproxy results allow the distinction of several climate periods, which may be associated with climatic phenomena such as changes in North Atlantic Oscillation (NAO) and/or solar activity. The influence of NAO−/NAO+ (negative/positive) is suggested to be related with the southward/northward displacement of the storm tracks resulting from the NAO−/NAO+ phases. For solar activity, the influence is explained through a direct increase in solar heating leading to calcite precipitation. The Dark Ages Cold Period (DACP, AD 450–750) reflects cold-dry climate conditions at this site, indicative of a positive North Atlantic Oscillation (NAO+) and low solar activity. The Medieval Climate Anomaly (MCA, AD 950–1250) exhibits wet-dry-wet and warm-cold-warm climate conditions. The wet/dry periods likely are associated with NAO−/NAO+, respectively, and the warm/cold period may reflect relatively high/low solar activity. The Little Ice Age (LIA, AD 1400–1850) is characterized by dry and cold climate conditions, suggesting the influence of NAO+ and low solar activity. Comparison of the results of this study with local and regional results suggests a generally similar climate pattern, which is indicative of similar climate mechanisms. The contradictions can be associated with age-related uncertainties, orographic differences, and/or other regional teleconnections.

Paleobiodiversity and paleoenvironments of the eastern Paratethys Pleistocene lacustrine-palustrine sequence in the Baklan Basin (SW Anatolia, Turkey)

The Lower-Upper Pleistocene sedimentary record of the Baklan Basin, a long-lived continental half-graben basin in SW Turkey, is characterized by shallow lacustrine and palustrine deposits. The paleoenvironmental changes recorded in the basin succession allow for a multiproxy approach in reconstructing the paleoclimatic, paleoecological, and paleobiogeographical evolution of southwestern Anatolia during the Early-Late Pleistocene. Based on sedimentological, paleontological, and geochemical data, three main types of depositional intervals have been identified, corresponding to different phases of a lake expansion cycle: The first interval is characterized by the perennial shallow lake environment (PSL deposits), which represents the very early stage of the Early Expansion System Tract (VEEST). This suggests a very early stage of lake transgression in arid climate conditions. The second interval is represented by the palustrine carbonate lake center environment (PLC deposits), which corresponds to the late stage of the Early Expansion System Tract (LEEST). This indicates a late early stage of lake transgression in semiarid to subhumid climates. The third interval is marked by the palustrine lake margin environment (PLM deposits), which represents the Late Expansion System Tract (LEST) under humid conditions.The Lower-Upper Pleistocene successions of the Baklan Basin provide an excellent example of lacustrine and palustrine deposition in a laterally extensive, low-gradient, shallow lake system in the semi-isolated Pontocaspian freshwater to slightly brackish water (oligohaline-low mesohaline) long-lived lake. The presence of Pontocaspian ostracod and mollusc faunas in the studied successions indicates that the largest major Caspian transgression around 2.6 millon years ago extended to SW Anatolia. The studied successions represent a rich archive of landscape, climate, and biotic development in the eastern Paratethys region during the Early-Late Pleistocene. The biogeographic signature of fossil faunas (mammals, ostracods, molluscs, and fishes) and floras (Characeae) is predominantly modern Palearctic and Holarctic, with a minor amount of endemic Pontocaspian elements. This study presents the Pleistocene Pontocaspian species of the Anatolian lakes that may have served as refugia for the Palearctic taxa during adverse time intervals. Consequently, this study shows that Lower-Upper Pleistocene lacustrine to palustrine sedimentation in the Baklan Basin has been controlled by the combination of tectonics, climate changes, and the largest major Caspian Sea transgression. The findings of this study could be used to evaluate the impact of similar allocyclic factors on the sedimentological, hydrological, and geochemical development of other intermontane lake basins.

Geochronology and geochemistry of the Miocene Kadıkalesi monzonite (Bodrum Peninsula, western Anatolia): Implications for its relation with the South Aegean Volcanic Arc

The Late Miocene igneous rocks of the Bodrum magmatic complex (SW Anatolia, Turkey), are composed of small monzonitic intrusions and trachyandesite-trachydacite volcanic rocks. The Kadıkalesi monzonite (KM) forms a small stock (<1 km2) made of plagioclase, biotite, hornblende, clinopyroxene, and quartz, and geochemically belongs to high-K calc-alkaline to shoshonitic, metaluminous series. The zircon separates from the KM yielded 9.5 ± 0.15 Ma core and 8.6 ± 0.04 Ma rim ages, revealing that emplacement of the monzonite continued up to ~8 Ma. The geochemical and mineralogical evidence suggests that the KM was derived by extensive fractionation of plagioclase, alkali feldspar, apatite, and clinopyroxene and/or Fe-Ti oxides and mixing of differently evolved melts. The monzonite has 760–866 Ma depleted mantle Nd Model ages which are considerably younger than the Cycladic and Menderes Massif plutons, as well as the other Miocene magmatic rocks from western Anatolia.On the basis of geochronological and geochemical features, we propose that the KM was fractionated from mafic melts derived from partial melting of spinel-facies (shallow depth) and crustally-contaminated (metasomatized/orogenic) asthenospheric mantle. Asthenospheric input were likely supplied from the slab window between the Aegean and Cyprian slabs, and likely contaminated by subducted sediments from the Aegean slab. It is also suggested that the current geodynamic setting of the Aegean region is also applicable to the Middle Miocene, meaning that the magmatic activity of the SAVA likely commenced at ~10 Ma, earlier than previously considered.

Earthquake history of the Milas Fault: an active dextral fault in an extensional province (SW Anatolia, Türkiye)

Earthquake history of the Milas Fault: an active dextral fault in an extensional province (SW Anatolia, Türkiye)

Interactions of invasive pumpkinseed with a riverine endemic fish indicate trophic overlap but minimal consequences for somatic growth and condition

The North American invasive fish pumpkinseed Lepomis gibbosus has been associated with some detrimental ecological consequences in some parts of its invasive range. Here, we tested the trophic interactions of pumpkinseed with the endemic stream fish Aegean chub Squalius fellowesii (‘chub’) in a Mediterranean-type water course in SW Anatolia, Turkey, using a bulk stable isotope approach (δ13C, δ15N). Seven sampling sites were able to be grouped as chub in pumpkinseed presence (n = 2) and absence (n = 3), and pumpkinseed in chub absence (n = 2). Across these groups, stable isotope metrics revealed that chub trophic (isotopic) niche size was similar in pumpkinseed presence/absence, but pumpkinseed had a larger niche in chub presence. In sites where they are co-habited, their niches showed some convergence, but with no apparent consequences for their growth or body condition, suggesting there were minimal ecological consequences of this sharing of food resources. These results suggest that the trophic consequences of this riverine invasion of pumpkinseed on this endemic chub was minimal.

Settlement, environment, and climate change in SW Anatolia: Dynamics of regional variation and the end of Antiquity.

This paper develops a regional dataset of change at 381 settlements for Lycia-Pamphylia in southwest Anatolia (Turkey) from volume 8 of the Tabula Imperii Byzantini-a compilation of historical toponyms and archaeological evidence. This region is rich in archaeological remains and high-quality paleo-climatic and -environmental archives. Our archaeological synthesis enables direct comparison of these datasets to discuss current hypotheses of climate impacts on historical societies. A Roman Climatic Optimum, characterized by warmer and wetter conditions, facilitating Roman expansion in the 1st-2nd centuries CE cannot be supported here, as Early Byzantine settlement did not benefit from enhanced precipitation in the 4th-6th centuries CE as often supposed. However, widespread settlement decline in a period with challenging archaeological chronologies (c. 550-650 CE) was likely caused by a "perfect storm" of environmental, climatic, seismic, pathogenic and socio-economic factors, though a shift to drier conditions from c. 460 CE appears to have preceded other factors by at least a century.

Late Cenozoic Stress State in Gulf of Güllük and Surroundings, SW Anatolia

This study was performed with the aim of revealing the Late Cenozoic stress state of the Gulf of Güllük and close surroundings. In this study, the tectonic regime and stress states from the Pliocene to the present day were determined. Mesoscopic fault plane data were collected from outcrops at 19 different stations in the region between the Gulf of Güllük and Milas. Additionally, focal mechanism inverse solutions were calculated for 12 earthquakes larger than M:3.0 occurring from 2004 to 2015 to reveal the current tectonic regime. According to kinematic analysis results from fault assemblages and focal mechanism solutions for earthquakes, two tectonic regimes affected the region before the Pliocene and at present. In the first tectonic regime, strike-slip faulting developed under a NW-SE oriented compressional regime. There was an R ratio of 0.426 between the principal stress axes and this shows faulting had transtensional character. The region converted to a NE-SW oriented extensional regime dominated by normal faulting in the Quaternary. This currently effective extensional regime was understood from focal mechanism solutions of earthquakes developing in the region. The reason for this regime being effective is the rapid pull by the African plate on the Anatolian plate, which rides above the African plate, and horizontal extension in the Anatolian plate.

Deformation in SW Anatolia (Turkey) Documented by Anisotropy of Magnetic Susceptibility Data

AbstractConvergence between the Eurasian and the African plates in the West Anatolian‐Aegean region results in a trench retreat due to slab roll‐back and tearing of the subducted African lithosphere. The upper plate response of this process gave way to back‐arc extension in the region. We have conducted a very detailed anisotropy of magnetic susceptibility (AMS) study on the Neogene rocks in SW Anatolia to unravel the style and magnitudes of deformation. For this purpose, from 83 sites in 11 structurally homogeneous domains, 1,680 paleomagnetic samples were analyzed. The results show that AMS fabrics are related to the tectonic deformation and that the magnetic lineation (maximum susceptibility axis, k1) is parallel to inferred maximum extension, while minimum susceptibility (k3) is typically normal to the bedding plane, corresponding to a preserved compaction associated with deposition fabric. The intermediate axis (k2) is parallel to a second extension direction and indicates that the region has been under the control of multi‐directional extension during the Neogene. Two main magnetic lineation directions are identified and represent Oligocene to middle Miocene E‐W, and late Miocene to Pliocene NW‐SE oriented extension. The magnetic lineation directions are dominantly parallel or perpendicular to the general strikes of the normal faults. The results show that the deformation in the region resembles two differentially stretched rubber sheets under the influence of SW oriented extension, exerted by the southward retreating Eastern Mediterranean subduction system.

Seismic record approach for the evaluation of natural hazards: a key study from SW Anatolia/ Turkey

Seismic record approach for the evaluation of natural hazards: a key study from SW Anatolia/ Turkey

Active tectonic and paleoseismological characteristics of the Dinar Fault, SW Anatolia, Turkey

Active tectonic and paleoseismological characteristics of the Dinar Fault, SW Anatolia, Turkey

Petrological and geochemical characteristics of the diabase and metasomatised dikes from the Tekirova ophiolite (SW Anatolia, Turkey): Tectonomagmatic evolution of the southern Neotethys

Ophiolites are widespread across the Anatolian plate and formed during the termination of different branches of the Neotethys ocean. The Tekirova ophiolite, situated in the Antalya ophiolite nappes in Southwest Anatolia, originated in the southern branch of the Neotethys. The former ophiolite consists of mantle and crustal sequences, in which, it is predominantly crosscut by the isolated diabasic dikes. Here, we have distinguished two dike types on the basis of their petrographic features and also degree of alteration. The relatively fresh types are generally named as diabase dikes. While the altered types are called as metasomatised dikes, and these dikes display ophitic to subophitic textures. The diabase and metasomatised dikes show enrichment in LILEs and depletion in HFSEs, indicating characteristics of suprasubduction zone ophiolites. This depletion of mobile elements may have been caused by metasomatism. The HFSEs versus HREEs diagrams show that the dikes were formed from 10 to 30% melting of extracted melts from previous mantle melting in which modified by subduction-derived fluids.

Active tectonics and kinematics of Fethiye-Göcek Bay, SW Turkey: Insight about the eastern edge of Pliny-Strabo Trenches

Pliny-Strabo Trench (PST)is a Subduction Transform Edge Propagator (STEP) fault developed at the northern edge of the African oceanic lithosphere connecting the Aegean and Cyprian trenches in the eastern Mediterranean. Recent studies have demonstrated that the PST terminates close to Turkish Border and links to the Cyprian trench east of Rhodes and south of Fethiye-Göcek Bay. However, it is also claimed that the PST extends into SW Anatolia along a sinistral transtensional shear zone, so-called Fethiye-Burdur Fault Zone (FBFZ) implying that a lithospheric tear in the downgoing plate extends into the over-riding plate, although, this is kinematically almost impossible since full mechanical coupling between down going and the over-riding plate is necessary. To test this hypothesis and understand the kinematics of the transition zone between PST and Cyprian trench we have conducted a rigorous paleostress inversion study combined with interpretation of 2D seismic data of which 228 km total length obtained from Fethiye-Göcek Bay.The seismic reflection data are used for the interpretation and delineation of off-shore faults and to determine their recent activity. The geometry and kinematics of the exposed on-land faults are determined by analyzing 13969 fault slip data obtained from 211 sites distributed evenly throughout in an area encompassing the bay in an area extending 70 km in E-W and 50 km in N–S that cover the whole area where the Pliny-Strabo STEP fault would emerge on-land.Results of analyses indicated that most of the faults in the study area are developed under multi-directional extension, except for some NE-SW-striking faults, which have dextral strike-slip components contrary to proposed sinistral nature of Fethiye-Burdur Fault Zone. Although there are numerous normal faults some which have been active until recently, however, there is almost no NE-SW striking sinistral strike-slip fault in the region to justify the presence of Fethiye-Burdur Shear Zone. Additionally, there are a number of earthquakes with dominantly strike-slip moment tensor solutions in the deeper part of the bay while they are in normal character in the on-shore areas suggesting that the Pliny-Strabo Trench stops very close to the shoreline and it does not propagate into SW Anatolia. Therefore, existence and alleged characteristics of the Fethiye-Burdur Fault Zone could not be verified.

The Formation and Evaluation of the Faulted Topography in the Burdur Basin, Lakes Region, SW Anatolia

The Burdur Basin, which is located in the Lakes Region in SW Anatolia, was formed by vertical faulting movements. The erosion surfaces were developed on the marl deposit in accordance with the lowering of the base level in each faulting movement in the east of the Burdur Basin. These erosion surfaces are at an elevation of 980, 995, 1040, 1115, 1200, 1300-1340 m on the Neogene marl deposit and knickpoints along the valleys indicate six times depressed along the fault lines of the Burdur Basin. The fault scarp extending on the east of the Burdur Basin was dissected deeply as a triangular facet; the accumulation of materials that had been transported from the highlands led to the formation of dejection fans, cones and re-deposited marl deposit in the eastern part of the Lake Burdur Basin. Earthquakes have occurred frequently since historical times and the subsidence that has taken place in the deeper part of Lake Burdur has attained a depth of more than 70 m in the southern part of the lake which may indicate continued tectonic activity. Lake Burdur, which is the remnant of Neogene Lake, containing some heavy minerals supports the life of only one species of fish and poor flora and fauna.

Reconstruction of Neogene Drainage in SW Anatolia (Turkey)

Reconstruction of Neogene Drainage in SW Anatolia (Turkey)