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411.
Vast marble deposits occur in a cover sequence of the Menderes Massif, SW Turkey. Four major marble deposits are recognized in Mu?la province based on the stratigraphic levels. These are Permo-Carboniferous aged black marbles (1), Triassic aged marbles (2), Upper Cretaceous aged marbles (3), and Paleocene aged pelagic marbles (4). This study deals with Triassic aged marbles of the southern part of the Menderes Massif. The Triassic marbles from SW Turkey consist of two big marble horizons in the Çayboyu (ÇM) and Kestanecik (KM) regions. The characteristic samples are collected from different stratigraphic levels in marble deposits in the ÇM and KM horizons. Mineralogical and major, trace, and rare earth element (REE) analyses of marble, limestone, and schist were conducted on these samples to reveal their petrographical and geochemical characteristics. The ÇM horizon is represented by calcitic marble layers. Nickel, cobalt, manganese, and iron elements filled in fractures, fissures, and intergranular spaces of calcite crystals and these elements give the pinky colour to the marble from the ÇM horizon. KM marbles were deformed, metamorphosed, and recrystallized under greenschist facies P–T conditions. As a result of the metasomatic reaction of magnesium and manganese rich fluids with marbles, dolomite, and manganese, minerals such as rhodochrosite and pyrolusite have crystallized along vein walls and layers in the KM horizon. Dolomitization was determined in KM marbles, whereas ÇM marbles show the character of limestone. MgO, MnO, Fe2O3, Ni, and Zn contents of marbles from the KM horizon are higher than those of ÇM marbles due to metasomatic reactions. The Sr content in white coloured marbles ranges between 11.20 ppm and 112.20 ppm and this concentration reaches up to 272.70 ppm due to metasomatic reactions and fluid intake. The REE content of Triassic marbles is independent of the abundance of carbonate and the REE enrichment observed due to syn-metamorphic fluid flow. The significant negative Eu anomaly in REE patterns indicates that the protoliths of Triassic marbles are carbonate rocks of sedimentary origin. 相似文献
412.
413.
Çağatay M. N. Görür N. Alpar B. Saatçılar R. Akkök R. Sakınç M. Yüce H. Yaltırak C. Kuşcu I. 《Geo-Marine Letters》1998,18(1):1-9
The Gulf of Saros is an Upper Miocene transtensional basin in NW Anatolia, formed by the interaction between the North Anatolian
Fault and the N-S extensional tectonic régime of the Aegean. The present configuration of the basin evolved mainly during
the Plio-Quaternary under the increased activity of the North Anatolian Fault. During the late Miocene-late Quaternary, no
sedimentation took place on the shelves. After this long hiatus, an important change in tectonic style about 0.2 Ma BP allowed
sedimentation to resume in the gulf.
Received: 14 February 1997 / Revision received: 12 November 1997 相似文献
414.
Under a climate change, the physical factors that influence the rainfall regime are diverse and difficult to predict. The selection of skilful inputs for rainfall forecasting models is, therefore, more challenging. This paper combines wavelet transform and Frank copula function in a mutual information‐based input variable selection (IVS) for non‐linear rainfall forecasting models. The marginal probability density functions (PDFs) of a set of potential rainfall predictors and the rainfall series (predictand) were computed using a wavelet density estimator. The Frank copula function was applied to compute the joint PDF of the predictors and the predictand from their marginal PDFs. The relationship between the rainfall series and the potential predictors was assessed based on the mutual information computed from their marginal and joint PDFs. Finally, the minimum redundancy maximum relevance was used as an IVS stopping criterion to determine the number of skilful input variables. The proposed approach was applied to four stations of the Nigerien Sahel with rainfall series spanning the period 1950–2016 by considering 24 climate indices as potential predictors. Adaptive neuro‐fuzzy inference system, artificial neural networks, and random forest‐based forecast models were used to assess the skill of the proposed IVS method. The three forecasting models yielded satisfactory results, exhibiting a coefficient of determination between 0.52 and 0.69 and a mean absolute percentage error varying from 13.6% to 21%. The adaptive neuro‐fuzzy inference system performed better than the other models at all the stations. A comparison made with KDE‐based mutual information showed the advantage of the proposed wavelet–copula approach. 相似文献
415.
Toxic effects of five commonly used pesticides on the biomass of a municipal activated sludge system were determined on the basis of the reduction in the oxygen uptake rate (OUR) and specific oxygen uptake rate (SOUR). Toxicity levels of the selected pesticides were determined by employing a modified OECD 209 (Organisation for Economic Cooperation and Development) method which was performed as batch experiments using a respirometer. Copper sulphate (CuSO4 · 5 H2O), copper oxychloride (Cu2Cl(OH)3), copper calcium oxychloride (CaCu3Cl2(OH)6) as copper‐based pesticides and chlorsulphuron (C12H12ClN5O4S), 2,4‐dichlorophenoxyacetic acid (2,4‐D) (C8H6Cl2O3) as synthetic organic pesticides were selected for the experiments. The EC50 values were determined to be 78, 249 and 281 mg/L for CuSO4 · 5 H2O, Cu2Cl(OH)3 and CaCu3Cl2(OH)6, respectively. Corresponding values for C12H12ClN5O4S and 2,4‐D were 860 and 3664 mg/L, respectively. Results indicated that toxicity effects of copper‐based pesticides were higher than that of synthetic organic pesticides. CuSO4 · 5 H2O was found to exert the highest toxicity among the copper‐based pesticides, whereas, C12H12ClN5O4S was determined to be the most toxic among the organic pesticides on activated sludge biomass. 相似文献