Sürdürülebilir Kalkınma Amaçları
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- MakaleYalnız künye2018Scopus SJRQ2Tracing provenance and chemical weathering changes in Ankara Stream sediments, central Turkey: Geochemical and Sr–Nd–Pb–O isotopic evidence
Saydam Eker, Çiğdem; Sipahi, Ferkan; Gümüş, Mustafa Kemal; Özkan, Özay
This study aims to analyze the changes in sediment provenance through the geochemical and Sr–Nd–Pb–O isotopic composition of the Ankara Stream bed and overbank sediments (ASBS and ASOS) and to examine the weathering and sediment transport processes in response to step climate variability. Major, trace, and rare earth elements, as well as Sr–Nd–Pb–O isotopic composition, exhibit generally similar variations for the investigated samples. These sediments have relatively high εNd(0) values and low 87Sr/86Sr ratios. Similar Pb isotopic ratios also characterize these sediments but have slightly different δ18O isotope values with relatively higher δ18O isotope values in the ASBS and lower δ18O isotope values in the ASOS samples. Chemical indices indicate low–moderate chemical weathering in the step-dominated climate. The low average Zr/Sc and Zr/Nb ratios indicate that such geochemical change was dominated by the composition of the source rocks but not sedimentary recycling with zircon enrichment, reflecting first-cycle deposit. Low radiogenic 87Sr/86Sr ratios and negative εNd(0) values indicate that the investigated sediments are relatively derived from young magmatic provinces, which are intermediate sources. Finally, the findings show that the geochemical compositions of the ASBS and ASOS were dominated by the composition of the source materials that originate from Galatia province and Late Cretaceous- Early Tertiary volcanic rocks in central Anatolia. Reasonable semiarid to arid climatic conditions are observed in the region. Active tectonism, increased erosion, and the investigated sediments are also transported rapidly to the stream channel without chemical alteration, and the sediments are the first-cycle products.
AtıfScopus9WoS7OpenAlex10İncele - MakaleYalnız künye2017Scopus SJRQ2Evaluation of potentially toxic element contents and Pb isotopic compositions in Ankara Stream sediments within an urban catchment in central Turkey
Eker, Çiğdem Saydam; Sipahi, Ferkan; Özkan, Özay; Gümüş, Mustafa Kemal
This study aimed to interpret the spatial distribution, enrichment factor (EF), and geo-accumulation of potentially toxic elements in the bed sediments (ASBS) and Pleistocene-aged overbank sediments (ASOS) of the Ankara Stream in Turkey. The potential toxic pollution of the investigated potentially toxic elements was defined by evaluating the EF, geo-accumulation index (Igeo), and Pb anthropogenic contribution. The distributions of As, Ni, and Co in the analyzed sediments were uniform in the ASBS and ASOS along the length of the stream. The EF and Igeo values indicated that ASBS and ASOS were significantly polluted by As and Ni and moderately polluted by Co, Zn, and Cu. ASBS was locally strongly polluted by Pb and Cd. Pb anthropogenic contribution was estimated at an average of > 100% in the ASBS and ASOS. The potentially toxic element levels and distribution patterns revealed that industrial activities, gasoline combustion, vehicular emission, phosphate fertilizers and natural sources were probable causes of metal pollution in Ankara Stream sediments. These potentially toxic elements were transported by atmospheric conditions and stream water. The potentially toxic elements in Ankara Stream increased with each passing day and were important in evaluating the potential toxicity risks to living organisms. Thus, suitable measures should be taken to ensure appropriate treatment of wastewater before toxic residues are disposed into the nearby stream. Chimney filter, treatment plants, and appropriate technology should be used in the organized industrial zone to prevent atmospheric pollution.
AtıfScopus12WoS10OpenAlex12İncele