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Öğe Mineralogy and geochemistry of marine palygorskite of upper paleogene age, (Southeastern Turkey)(Geological Society of America, 2018) Özsaraç, Şafak; Yalçın, Hüseyin; Tetiker, SemaThis study contains Becirman Formation of Late Paleogene age outcropping Batman-Gercus and Mardin-Dargecit areas in the Southeast Anatolian Authouctonous of Arabian Plate. The unit is formed of red colored dolomitic shale-marl-sandstone and white-cream colored carbonate rocks (dolomite, dolomitic limestone) intercalations. According to whole-rock analyses results of X-ray diffraction (XRD), minerals are represented, respectively in abundance, dolomite, phyllosilicate (palygorskite, smectite, chlorite, vermiculite, illite, serpentine and mixed layered C-V), calcite, feldspar, quartz, hematite and goethite. Phyllosilicates determining on XRD clay fractions comprise mineral paragenesis with palygorskite + smectite or vermiculite in Gercus area and palygorskite + chlorite + vermiculite / C-V, and chlorite + illite + serpentine in Dargecit area. Palygorskite minerals (2-10 mm-fibres length) occurred after dolomites and matrix in the dolomitic marl and sandstones, respectively, on scanning electron microscope (SEM) studies. Other associated minerals as smectite and chlorite / C-V are observed as thin leaves. Major element geochemistry of palygorskite-rich clay fractions indicates that these minerals are rich in Mg-Al-Fe. Trace element quantities of palygorskites on normalized spider diagrams have enrichments and depletions, respectively, compared to chondrite and North America Shale Composites (NASC). SEM views, existence of serpantine, especially increase of Cr and Ni concentrations, which indicate that the source of Becirman Formation is serpentinized ophiolitic rocks of Upper Cretaceous age in north of the basin. On the other hand, palygorskites are formed from dolomites and matrix by mechanisms of diagenetic transformation and sedimentary neoformation, respectively.Öğe Geochemistry of the cretaceous-tertiary (K/T) transition clays in the Southeastern Turkey(Komitet Zrównoważonej Gospodarki Surowcami Mineralnymi PAN, 2024-04-17) Tetiker, SemaThe mineralogy and chemistry of Upper Cretaceous -Lower Paleocene claystone sediments from Mardin and Batman, southeastern Turkey, were analyzed. The main mineral paragenesis in the Upper Cretaceous member formed chlorite-smectite (C -S) and illite, while the Lower Paleocene member occurred of chlorite -vermiculite (C -V) and vermiculite minerals. The clays were silica -poor but indicated high values of Al, Fe, Mg, Cr, Ni, V, and Zr. Lower contents of the alkali elements (Na, Ca, Mg, K) of the clayey sediments suggests a relatively denser weathering of the source area. The mineralogical compositions, major element ratios, trace, and rare earth element (REE) contents of the sediments show that the Upper Cretaceous member consists of materials with a mainly felsic source lithology, while relatively contributions from basic sources are found in the Lower Paleocene unit. A comparison of the major and trace element contents of the phyllosilicate/clay minerals with the members revealed that the patterns of the clays were different from each other, although the enrichments/decreases varied depending on the origin (basement rocks or detrital) of the derived rocks, minerals, and elements. REE content of clays increased from detrital to phyllosilicate/clay minerals of chemical/diagenetic/neoformation origin during the Lower Paleocene. During the Cretaceous and Tertiary periods, local or regional geodynamic and diagenetic events largely governed the rock sedimentation processes and provenance variations amongst Germav Formation members.
