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A New Late Holocene Eolianite Record from Altinkum Beach, North Cyprus
(Tubitak Scientific & Technological Research Council Turkey, 2012) Erginal, Ahmet Evren; Kiyak, Nafiye Gunec; Ertek, Topcu Ahmet
In this study, we investigated the main depositional characteristics and obtained Optically Stimulated Luminescence (OSL) ages of coastal eolianite on the north coast of Cyprus, where this occurrence had not previously been recorded. Based on EDX/SEM and XRD data and field observations, the studied eolianite that crops out between elevations of 1 m and 14 m a.s.l. is made up predominantly of quartz grains, most of which consist of medium- to fine-grained sand. The rock comprises aragonite, calcite and quartz with lesser amounts of bornite and hematite as accessory minerals. OSL ages indicated that the initial deposition of eolianite sands took place at 1.51 +/- 0.21 ka years ago.
A new late Holocene eolianite record from Altınkum beach, North Cyprus
(2012) Erginal, Ahmet Evren; Kıyak, Güneç Nafiye; Ertek, Topçu Ahmet
Bu çalışmada, daha önce bu konuda bir bulgunun kaydedilmediği Kuzey Kıbrıs kıyılarında tespit edilen kıyı eolinitinin başlıca birikim özellikleri ve Işık Uyarımlı Lüminesans yaş verileri araştırıldı. EDX/SEM ve XRD verileri ve arazi gözlemlerine göre deniz seviyesinden itibaren 1?14 m yükseltiler arasında yüzeyleyen eolinitte orta-ince kum boyutundaki kuvars taneleri egemendir. Kayaç aragonit, kalsit ve kuvars dışında az oranda bornit ve hematit içerir. OSL yaşları Eolinit kumlarının ilk birikim yaşının günümüzden 1.51±0.21 bin yıl önce biriktiğini göstermektedir.
A Preliminary Note on Depositional Characteristics and Optical Luminescence Age of a Marine Terrace, Strait of Canakkale, Turkey
(Coastal Education & Research Foundation, 2013) Avcioglu, Mustafa; Erginal, Ahmet Evren; Kiyak, Nafiye Gunee; Kapan-Yesilyurt, Sevinc; Yiğitbaş, Erdinç
Avcioglu, M.; Erginal, A.E.; Kiyak, N.G.; Kapan-Yesilyurt, S., and Yigitbas. 2013. A preliminary note on depositional characteristics and optical luminescence age of a marine terrace, Strait of Canakkale, Turkey, Journal of Coastal Research, 29(1), 225-230. Coconut Creek (Florida), ISSN 0749-0208. This preliminary study investigated the depositional features and optical luminescence age of marine terrace sediments located on the east coast of the Strait of Canakkale, Turkey. With regard to depositional setting, the studied sequence is formed mostly of shallow marine deposits rich in quartz and oysters as well as other accessory minerals and various fossil sea shells. In vertical section, the sequence is characterized by two different stratigraphic units, i.e. a 1.50-m-thick sandy to gravely bottom unit (unit A) and an overlying 2.5-m-thick fossiliferous zone (unit B). On the basis of optically stimulated luminescence (OSL) age estimations obtained from six sampling levels from bottom to top, we determined superimposed cycles of deposition during interglacials from 246.47 +/- 25.32 ka (unit A) at MIS 7 to 127.48 +/- 8.91 ka (unit B) at MIS 5.
Aeolian imprints of multiple Mediterranean invasions of the Black Sea during Pleistocene
(Elsevier, 2022) Erginal, Ahmet Evren; Kiyak, Nafiye Gunec; Makaroglu, Ozlem; Bozcu, Mustafa; Ozturk, Muhammed Zeynel; Selim, Haluk Hamit; Nowacyzk, Norbert R.
Climate changes determined the repeated connections between the Black Sea, Caspian Sea and Mediterranean Sea. The landlocked anoxic Black Sea basin was exposed to several transgressions throughout Quaternary by the Mediterranean Sea through the Straits of Istanbul (Bosphorus) and by the Caspian Sea through the Manych-Kerch spillway. Sedimentological records of these connections are limited mostly to the marine terrace deposits of Marine Isotope Stage (MIS) 5e while the pre-MIS 5e period remains uncertain due to a lack of robust facies and chronological data from deep-sea sedimentary sequences. Here we discuss the imprints of multiple Mediterranean transgressions during Middle Pleistocene in the Black Sea based on facies analysis and the optical age of coastal carbonate aeolianites. Contrary to today's hydro-climate of the Black Sea, the aeolianites bear witness to the transformation of the Black Sea into a warm inland sea during successive Mediterranean invasions. Prior to the onset of aeolian deposition, paleosols were formed on the Eocene-aged hardened sandy silts, suggesting strongly washed soil. This is evidenced by no calcium carbonate and a high Rb/Sr ratio, with quartz amounting to of 99.8%. According to our OSL ages, carbonates deposited on the shelf plain under higher temperature and increased evaporation conditions in MIS 15 and the later interglacial phases were transported to the coastal sand dunes during the transitional phases of MIS 15-14, MIS 13-12, MIS 11-10 and MIS 9-8. We suggest that the carbonate-rich and ooid-containing aeolianites were repeatedly formed in the multiple Mediterranean transgression stages, beginning with an increasingly severe dry phase following the Brunhes-Matuyama magnetic reversal.
Age, composition and paleoenvironmental significance of a Late Pleistocene eolianite from the western Black Sea coast of Turkey
(Pergamon-Elsevier Science Ltd, 2013) Erginal, Ahmet Evren; Kiyak, Nafiye Gunec; Ekinci, Yunus Levent; Demirci, Alper; Ertek, Ahmet; Canel, Timur
On the basis of field observations, thin section interpretations, microanalytical data, electrical resistivity survey and luminescence dating, the age, composition and internal structure of coastal eolianite on the west Black Sea coast at Sile, Istanbul, was studied for a combined interpretation of dune rock development and facies characteristics. Results demonstrate that the eolianite is made up of south-dipping, large-scale dune stratification, consisting mainly of quartz sand and, in particular, abundant ooids, as well as the binding cement which is composed of calcite and aragonite. Based on Electrical Resistivity Tomography (ERT) images, the eolianite has a thickness of between 3.5 m and 8 m and overlies a buried rugged topography that has developed on the Pliocene unit. This suggests the predominance of northerly winds that account for the landward removal of dune sands by offshore wind drift prior to carbonate cementation. Optically Stimulated Luminescence (OSL) dating estimations revealed that the initial deposition of the laminated eolianite layers on the underlying older unit took place at 138.57 +/- 13.65 ka, matching the Karangatian highstand or Marine Isotope Stage (MIS) 5e. (C) 2012 Elsevier Ltd and INQUA. All rights reserved.
Aktaş Gölü Dip Çökellerinin Kuzeydoğu Anadolu’nun Geç Holosen İklimi Açısından İrdelenmesi
(2016) Karlıoğlu, Nurgül; Akgül, Rıza; Erginal, Ahmet Evren; Caner, Hülya
Bu projenin konusunu, suları sodalı olan ve Kuzeydogu Anadolu'da bulunan Aktas Gölü'nün dip çökellerinin paleoiklimsel göstergeleri olusturmaktadır. Gölde ilk kez sedimantolojik ve paleolimnolojik çalısmalar yapılarak radyokarbon tarihlendirmesi ile çökelme hızı belirlenmeye çalısılmıstır. Gölden alınan 67cm (AC1) ve 81 cm (AC2) derinlikteki karotlar üzerinde yapılan palinolojik analizlerden elde edilen verilere göre günümüzden yaklasık 685 yıl önce bölgede Gymnospermae (Açık tohumlular) odunsu bitki türlerinden basta sarıçam (Pinus sylvestris) ve dogu ladininin (Picea orientalis) hâkim oldugunu göstermistir. Ayrıca çökelme süresince kalsiyum karbonat ve organik karbon çökeliminde dalgalanmalar oldugu görülmüstür. Bu amaçla alınan karotlardan 1 cm'lik örneklemeler üzerinden ayrıntılı toplam organik karbon ve CaCO3 analizleri yapılmıstır. AC2 karotu boyunca toplam organik karbonun en fazla çıktıgı seviyelerden (5, 66 ve 80 cm den) AMS tarihlendirmesi için örnekler alınmıs ve bu örnekler Beta Laboratuvarı'na (Florida-Amerika) gönderilmistir. Karotun en derin seviyesi olan 80 cm deki organik sediment örneginin AMS tarihlendirmesi günümüzden 685 yıl önce olarak belirlenmistir. Ayrıca, karotlar üzerinde 5 cm örneklemeler üzerinden ayrıntılı diatom analizleri de yapılmıstır. Bu projeyle birlikte güncel polen dagılımının belirlenmesi için, Avrupa Polen Izleme Programı?nın belirledigi kriterlere göre ilk defa göl çevresine 4 adet Tauber tipi polen tuzagı 2015 yılının Haziran ayında yerlestirilmis, fakat bunlardan 3'ü çevredeki insanlar tarafından tahrip edilmistir. Sadece göl kenarındaki polen tuzagından (AP1) elde edilen güncel polen yogunlugu verilerine (cm2/yıl) göre, 2015-2016 yılları arasında göl çevresinde otsu bitki polen yogunlugu (NAP) odunsu bitki polen yogunluguna (AP) kıyasla daha fazla çıkmıstır. Fosil ve güncel polen analizlerinden elde edilen verilere göre günümüzden 685 yıl önce göl çevresinde odunsu bitki türleri hâkim iken günümüzde artık alanda otsu bitki türleri baskın hale gelmistir. Bunun sebebi insan etkisi yanında iklimde görülen soguk-nemli dönemden kuraklık egiliminin arttıgı döneme dogru geçisin olmasıdır.
An Under?Recognised Geoarchaeological Heritage Asset in Turkey: Dana Island, Mersin
(Springer, 2021) Erginal, Ahmet Evren; Öniz, Hakan; Erenoğlu, Oya; Sarıaltun, Savaş
Carbonate eolianites on Turkey’s 8333-km long coastline are extremely rare occurrences. Following pioneering studies at Bozcaada Island and Şile on the Aegean and Black Sea coasts, respectively, a new eolian geosite was recently found on Dana Island, an archaeological conservation area on the Mediterranean coast of Turkey. The eolianite, which was probably formed in a warm interglacial phase during Late Quaternary, is biogenic calcarenite in composition and contains a thick paleosol and well-preserved rhizoliths as root cast structures. As well as being a geological inheritance, the fact that eolianites are interbedded with very rare hard carbonate-cemented slope debris (colluvium) and both units are home to possibly the largest rock-cut ancient shipyard in the Eastern Mediterranean makes the island a unique geoarchaeological example with immense potential. These geological and archaeological heritage elements on Dana Island are sufcient evidence to identify the eolianites as a geoarchaeological heritage.
Analysis of Toxic Metal-Induced Ecological Risk in Kepez Stream, Çanakkale, Türkiye
(2023) Çavuş, Havva; Kükrer, Serkan; Sağlam, Müberra; Erginal, Ahmet Evren
Ecological risk in the mouth of Kepez Stream has recently increased notably due to waste from the Kepez settlement, agricultural activity in the Kepez delta, maritime traffic in the Çanakkale Strait, and summer houses in the coastal area. This study analyzed the ecological risk of 10 sediment samples along the bed in the mouth of Kepez Stream to shed light on anthropogenically induced pollution. The pollution proxies such as chlorophyll degradation products, heavy metal concentrations and organic carbon of the sediment samples were determined. Enrichment Factor (EF), Contamination Factor (CF), Geoaccumulation Index (Igeo) and Potential Ecological Risk Index (PER) were calculated from the results obtained. Spearman's correlation analysis and factor analysis were also performed. The obtained data show that there is moderate enrichment of Zn, As and Co, a significant level of Pb, and very high level of Cr in the sediments of Kepez Stream. Ni enrichment was determined to be excessive and poses a high potential ecological risk. Cleaning and rehabilitation need to be carried out urgently in the mouth of Kepez Stream. It should be determined whether metals are being transmitted to aquatic organisms, and measures should be taken to reduce the sources of pollution.
Beachrock Cementation Patterns Along the Gulf of Aqaba Coast, Saudi Arabia
(Springer Heidelberg, 2019) Haredy, Rabea A.; Ghandour, Ibrahim M.; Erginal, Ahmet Evren; Bozcu, Mustafa
Beachrocks crop out along the Saudi coast of the Gulf of Aqaba with beds lying at elevations up to 0.8 m above the present sea level and with seaward extents that repeatedly submerge and emerge during high and low water levels. This study discusses the cement composition, petrography and bedding features of beachrocks at 24 different locations, of which a total of eight sites were sampled. The study focuses on the petrographic and microtextural characteristics of the beachrocks to elucidate their cementation environment and diagenetic evolution. The results revealed the predominance of three main cement types: (1) fibrous aragonite cement with morphologies including isopachous rims around grains with or without micritic substrates, pore-filling radial aggregates, pseudospherulite and randomly oriented interlocking aragonite fibers; (2) microcrystalline low-Mg calcite (LMC) cement binding grains and filling inter-and intra-granular pore spaces; and (3) micritic cement in the form of envelopes and/or pore-filling micrite in some samples with meniscus bridges. The last two types also contain infiltrated silt-sized clasts and skeletal remains. The cements indicate precipitation mainly in pore-filled marine phreatic diagenetic zone and, rarely, in the marine vadose zone with the aid of microbial and algal activity. Petrographic investigations and energy-dispersive X-ray spectroscopy of selected samples showed the occurrences of aragonite and LMC.
Beachrock formation on the coast of Gokceada Island and its relation to the active tectonics of the region, northern Aegean Sea, Turkey
(Pergamon-Elsevier Science Ltd, 2016) Avcioglu, Mustafa; Yiğitbaş, Erdinç; Erginal, Ahmet Evren
There are beachrock formations in 5 different sections of the south coast of Gokceada, Turkey's largest Aegean island. These beachrocks form two different groups in terms of layering characteristics, delta O-18 and delta C-13 stable isotope compositions, consecutive cementation structures, and C-14 dating. The West Group beachrocks, to the west, were dated to 4010-5830 BP, while the East Group beachrocks were dated to 620-2390 BP. The beachrock formations in both groups are separated by the NE-SW-trending Ugurlu Fault. The Ugurlu Fault is a right lateral, strike slip with reverse component oblique fault, and is an active fault within the North Anatolian Fault Zone. In the period between the formation of the two beachrock groups (2390-4010 BP), an earthquake was responsible for the destruction of Gokceada Yenibademli mound and the development of two generations of beachrock. (C) 2015 Elsevier Ltd and INQUA. All rights reserved.
Cementation characteristics and age of beachrocks in a fresh-water environment, Lake Iznik, NW Turkey
(Elsevier, 2012) Erginal, Ahmet Evren; Kiyak, Nafiye Gunec; Ozturk, Muhammed Zeynel; Avcioglu, Mustafa; Bozcu, Mustafa; Yiğitbaş, Erdinç
This paper focuses on the cement characteristics and optical luminescence age of late Pleistocene-Holocene beachrock, exposed on the southeast shore of freshwater Lake Iznik in northwest Turkey, based on field observations, various spectroscopic analyses and optical dating results. The studied beachrock is a poorly-sorted coastal conglomerate composed mostly of gravels derived from surrounding volcanic rocks and marbles as well as quartz and carbonate grains. We identified different types of cements; dominated by micritic envelopes, bladed isopachous aragonite rims, void fills, radial aggregates and meniscus bridges, implying no single origin. Cementation characteristics indicate that marine-like cement micro-fabrics may occur in freshwater lake environments where the lake-water chemistry favors carbonate precipitation. OSL data revealed the existence of older beachrock dating back to 20.2 ka, together with younger Holocene-age beachrock of between 5.6 and 2.4 ka. This suggests that younger beachrocks have been superimposed on older cemented carbonates through the removal of carbonates by wave motion (splash and spray) during lower lake level conditions. (C) 2011 Elsevier B.V. All rights reserved.
Characterization of a Landslide using Seismic Refraction, Electrical Resistivity and Hydrometer Methods, Adatepe - Canakkale, NW Turkey
(Environmental Engineering Geophysical Soc, 2011) Bekler, Tolga; Ekinci, Yunus Levent; Demirci, Alper; Erginal, Ahmet Evren; Ertekin, Can
Seismic refraction and electrical resistivity surveys were carried out to characterize a landslide that occurred near the Canakkale-Lapseki-Bursa highway, in northwest Turkey. Hydrometer analyses were also performed to highlight the composition of the slip surface material. The combined interpretation of the methods yielded the mass of the landslide body and the possible subsurface nature of a basal slip plane. Sediment-size fraction maps show that the slip surface material contained an excessive amount of clay. The clay-rich slipping layer was observed to a maximum depth of 4-5 in marked by a low (2-4 ohm-m) resistivity zone, contrasting with the underlying sand-rich beds with relatively higher resistivities (>6 ohm-m). A velocity variation ranging between similar to 1,250-1,500 m/s also characterized this water-saturated slipping zone. Results indicated a buried failure surface under the studied shallow slide mass, which appeared to be a prolongation of the long upward-concave slip surface of the old landslide area to the east. Thus, future reactivations can be expected along basal slip surfaces of both recent and old landslide areas, which may pose a risk for the road structure and vehicular traffic along the active Canakkale-Lapseki-Bursa highway.
Co-seismic beachrock deformation of 8th century AD Earthquake in Middle Strand of North Anatolian Fault, Lake Iznik, NW Turkey
(Elsevier, 2021) Erginal, Ahmet Evren; Erenoğlu, Ramazan Cüneyt; Yıldırım, Cengiz; Selim, H. Haluk; Kıyak, Nafiye Güneç; Erenoğlu, Oya; Ulugergerli, Emin
A historical earthquake-related co-seismic deformation observed on beachrock beds along the southern shoreline of Lake Iznik is discussed as a new paleoseismic record for an 8th century AD earthquake in the Middle Strand of the North Anatolian Fault, NW Turkey. Electrical Resistivity Tomography (ERT) images beneath the beachrock surface allowed monitoring of the subsurface trace of a normal fault dipping north along a 100 m surface rupture. No strike-slip deformation exists along the rupture, suggesting that the deformation in the beachrock is connected with a secondary structure, and that the main surface rupture was under the lake waters. The deformed beds of the beachrock, dated using Optically Stimulated Luminescence (OSL) to 1.3 ± 0.15 ka, are overlain by an undeformed secondary deposition of beds dated to 1.2 ± 0.09 ka. This allows us to narrow down the time of the faulting and implying that it was most likely a result of the AD 715 earthquake.
Depositional Characteristics of Carbonate-Cemented Fossil Eolian Sand Dunes: Bozcaada Island, Turkey
(Coastal Education & Research Foundation, 2013) Erginal, Ahmet Evren; Ekinci, Yunus Levent; Demirci, Alper; Avcioglu, Mustafa; Ozturk, Muhammed Zeynel; Turkes, Murat; Yiğitbaş, Erdinç
Erginal, A.E.; Ekinci, Y.L.; Demirci, A.; Avcioglu, M.; Ozturk, M.Z.; Turkes M., and Yigitbas, E., 2013. Depositional characteristics of carbonate-cemented fossil eolian sand dunes: Bozcaada Island, Turkey. Journal of Coastal Research, 29(1), 78-85. Coconut Creek (Florida), ISSN 0749-0208. Coastal eolianite on the south coast of Bozcaada Island, Turkey, was investigated by field observations, petrographic and climatological examinations, and electrical resistivity tomography data. The 4- to 7-m-thick eolianite, including rhizolith morphotypes characterized by root tubules and bifurcated root casts, demonstrates dune-sand accumulation during the Upper Pleistocene. Our results showed that paleowind drift and recent windblown sand drift on the island are similar. The dune sands exhibit various cement types formed of calcite and aragonite, such as micrite encrustations, meniscus and gravitational cements, and in particular, void fills. Dune-sand accumulation took place on the truncated surface of Miocene deposits. Geophysical data showed the existence of large weathered cavities within the eolianite and a high-angle normal fault, which displaces the eolianite, together with the underlying Miocene unit.
Distribution, sources and ecological risk assessment of metals in Kura river sediments along a human disturbance gradient
(Taylor and Francis, 2021) Kukrer, Serkan; Tunc, I. Onur; Erginal, Ahmet Evren; Bay, Ozender; Kilic, Seref
Monitoring the pollution status of freshwater resources is an important step in sustainable planning. This study aimed to determine the distribution and sources of metals in the sediments of the transboundary eastern Anatolian/Caucasus region Kura river as well as its ecological risk level. Surface sediment samples were collected from eight sites along the human disturbance gradient. Multi-element analyses of the collected samples were performed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Chlorophyll degradation product (CDP) analysis was performed spectrophotometrically. OC analysis was carried out using the titration method. The data obtained were evaluated using the indices of enrichment factor, geo-accumulation, modified hazard quotient and ecological contamination index and potential ecological risk. The average content of metals in the sediment at the eight sites was of the following descending order from highest to lowest: Al > Mn > Zn > V> Ni > Cr > Cu > Co > Pb > As > Cd > Tl > Hg. According to the distribution of raw metal values, urbanization is not the only factor controlling metal distribution. Adsorption processes and organic material content also emerge as an important factor. Enrichment factor values were of the following order: T1 > Pb > Mn > Hg > Cr > Co > Cd > Ni > As > Zn > Al > Cu > V. Results revealed that the sources of Cu, V and Al were lithogenic, in contrast to Tl, Pb, Mn, Hg, Cr, Co, Cd, Ni, and As, thus pointing to human-induced accumulation. According to the potential ecological risk index, these elements have the potential to create medium-to-high level ecological risks and were substantially of atmospheric origin. The ecological contamination index is also consistent with these findings in terms of risk level. A municipal waste stream, fossil fuel burning and a cement plant operating in close proximity also appeared to be the possible sources.
Ecological Risk Analysis of Lake Arin Sediments (Bitlis, Türkiye)
(2023) Faydalgel, Sümeyye; Erginal, Ahmet Evren
This study aimed to determine the ecological risk of Lake Arin through an analysis using comprehensive indexes. Surface sediment samples (21) and bedrock samples (5) were collected from Lake Arin. The metal concentrations were obtained from the ICP-OES analysis values. Enrichment Factor (EF), Contamination Factor (CF), Geoaccumulation Index (Igeo) and Toxic Risk Index (TRI), Modified ecological risk index (mER) and Modified Potential Ecological Risk Index (m-PER) were calculated from the ICP-OES data. Our results reveal that the average concentration of the Lake Arin metals is Al > Fe > Mn > Zn > Ni > Co > Pb > Cd > As, in decreasing order. While moderate enrichment was determined for Ni, As and Zn, moderate contamination was detected only for Ni. It was determined there was no contamination in terms of Geoaccumulation Factor, and PER values showed low ecological risk. The second highest EF value belongs to As, which is thought to originate from the use of fossil fuels in the region. As a result of the ecological risk analysis of Lake Arin, it was determined that the metal levels were not at high levels and were not toxic.
Ecological risk assessment of surface sediments of cardak Lagoon along a human disturbance gradient
(Springer, 2020) Kukrer, Serkan; Erginal, Ahmet Evren; Kilic, Seref; Bay, Ozender; Akarsu, Taylan; Oztura, Erdal
Lagoons are the hotspot ecosystems whose sustainability should be secured using the ecological assessment indicators. This study aimed to quantify the surface sediment metal distributions of cardak Lagoon in the Marmara region of Turkey, to characterize their natural and anthropogenic sources and transport mechanisms and to assess their potential ecological risks. The surface sediment samples were collected from 11 stations using Van Veen grab, while for the background values to be determined, core sampling was used from two stations. The analyses of multiple elements, total organic carbon, carbonate, and chlorophyll degradation by-products were carried out to characterize sediments. Enrichment factor and the indices of potential ecological and toxic risks were applied to assess the ecological status of the surface sediments. The operation of the gold mine in the close vicinity was found to be responsible for the enrichment of Au and Hg in the lagoon sediments. Cd, Tl, Sb, and Sr were the other elements responsible for the enrichment. The potential risk levels of the lagoon varied between the low and significant levels. The riskiest elements were found to be Hg and Cd which in turn pointed to the mining and agricultural activities as the most dominant human disturbance. The toxic risk index of cardak Lagoon was estimated to range from 5.21 to 11.00, with a low mean value of 7.98. The C:N ratio range of 8.52 to 134.93 (a mean of 29.07) indicated that the organic C source was mostly of the terrestrial origin, in particular, from the surrounding agricultural lands.
Ecological Risks Caused by Heavy Metal Accumulation in Umurbey Plain (NW Türkiye)
(İstanbul Üniversitesi, 2024) Bay, Özender; Kükrer, Serkan; Erginal, Ahmet Evren
This study aims to assess the ecological risks in the agricultural soils of the Umurbey Plain in Çanakkale, NW Türkiye. To evaluate the anthropogenic impact on the studied soil samples, various indices and statistical analyses were employed. Our results revealed that the elements Cu, Cr, and Ni exhibited very high contamination levels at all stations. As showed high contamination at nearly all other stations, with a strong positive correlation to CaCO₃. Ni, Cd, Cr, and As demonstrated moderate to significant enrichment at these stations. Cu displayed very high to significant enrichment, likely associated with the use of bordeaux mixture in fruit orchards. The calculated average mEri values indicated that Ni, As, Cu, and Cd posed significant potential ecological risks at many stations, while other elements, including Hg and Tl, also presented risks. The Spearman correlation analysis among the variables revealed that the sources of the metals Pb, Zn, Mn, Fe, V, and Cd differed from those of Ni, As, and Cr.
Environmental changes based on multi-proxy analysis of core sediments in Lake Aktas, Turkey: Preliminary results
(Pergamon-Elsevier Science Ltd, 2018) Kilic, Nurgul Karlioglu; Caner, Hulya; Erginal, Ahmet Evren; Ersin, Sinem; Selim, H. Haluk; Kaya, H.
A sediment core covering the last millennium from Lake Aktas, a shallow alkaline soda lake in the northeast Anatolian highland of Turkey, was studied for pollen and physical and chemical proxies to reconstruct past climate change. The sediments were dated by AMS radiocarbon dating of bulk organic carbon. Among arboreal pollen (AP) from around 930 years ago, dominant trees were Pinus sylvestris, Picea orientalis, Abies, Betula, Fagus, and Quercus. AP exceeded NAP (non-arboreal pollen) in this time, whereas the opposite is the case in a pollen trap in the same region collecting the pollen for one year in 2015-2016. The comparison of modern and fossil pollen influx indicates that in that period trees were more widely distributed around the lake than today, where steppe vegetation now prevails. Inferred causes for the disappearance of trees are anthropogenic impacts and climatic change towards more continental conditions. The results also identify the onset of the Little Ice Age in the NE Anatolian highland of Turkey. (C) 2018 Elsevier Ltd and INQUA. All rights reserved.
Environmental impact of potentially toxic elements accumulated in surface sediments of the Erikli Lagoon, Black Sea coast (Turkiye)
(Walter De Gruyter Gmbh, 2024) Kukrer, Serkan; Uludag, Musa; Erginal, Gulsen; Erginal, Ahmet Evren
This study aims to (a) determine the concentration and distribution of elements in the surface sediments of the Erikli Lagoon, which are under natural and anthropogenic pressure, (b) determine possible effects on the environment using ecological indices, and (c) reveal possible sources. Multiple elements, total organic carbon and chlorophyll degradation products were analyzed in sediment samples. Enrichment factor (EF), contamination factor (CF), and geoaccumulation index (Igeo) were calculated to determine the sources of the elements. Modified hazard quotient (mHQ), ecological contamination index (ECI), contamination severity index (CSI) and potential ecological risk index (PERI) were calculated to determine ecological risks. It was found that Mn, Hg, As, Fe and Cd entering the lake are of anthropogenic origin. These elements pose a low to moderate ecological threat to the lake. Agricultural and domestic discharges and atmospheric deposition are the main sources of these elements. A moderate ecological risk with an average value of 194.89 was determined in the lagoon based on PERI and contamination levels of metals. The elements that pose this risk are Hg and Cd, due to their high toxicity. According to ECI and CSI, the ecological risk is low, with average values of 0.99 and 0.30, respectively.

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