Naslov
Clay characterization in sediment cores from Novigrad sea area, Croatia

Autori
Fiket, Željka ; Bermanec, Vladimir ; Kniewald, Goran

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Abstracts of the 20th General Meeting of the International Mineralogical Association (IMA2010) ; u: Acta Mineralogica-Petrographica : Abstract Series / Pál-Molnár, Elemér - Budimpešta, 2010, 399-399

Skup
General Meeting of the International Mineralogical Association (20 ; 2010)

Mjesto i datum
Budimpešta, Mađarska, 21.08.2010. - 27.08.2010

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
clay; sediment cores; Novigrad; Croatia

Sažetak
The Novigrad sea is a small, semi-closed bay located in the central part of the eastern Adriatic coast, about 20 km north of Zadar (Fig. 1). It is connected to the Adriatic sea in the northwest by Velebit channel and the Karin sea in the southeast. In the surrounding area several bauxite deposits have been exploited for many years with the transshipment port situated in the Novigrad sea. Assessment of the influence of dispersion of bauxite dust by wind and water from dozens of open bauxite pits and waste disposal site of an abandoned alumina plant in the vicinity of the Novigrad sea on the environment is necessary. Clay minerals have an important role in aquatic systems, as both a carrier and source of pollutants. Therefore, detailed characterization of clay content in recent marine sediments is a prerequisite for an assessment of source and distribution pathways of contaminants. In case of high carbonate content of studied sediments, removal of carbonate phases prior to detailed clay analysis is necessary. Removal of carbonate minerals from sediments at room temperature was investigated by three different acids, hydrochloric acid (0.5M HCl), acetic acid (4M CH3COOH) and formic acid (4M HCOOH). Our aim was to evaluate the effects of different chemicals on the properties and structures of present clay minerals in order to develop the optimal procedure for further detailed characterization of clay minerals in marine sediments of the Novigrad sea area. The analysis was performed on two sediment cores of different carbonate content, one from Novigrad sea NM (~19% CaCO3) and one from Karin sea KM (~31% CaCO3) (see Figure 1). X-ray diffraction was used to obtain mineralogical composition of the bulk, carbonate free, as well as glycolated and heat-treated (at 450°C and 550°C) samples. Results indicate that the bulk samples are dominantly made up of carbonates (calcite – Ca and dolomite – D), quartz (Q) and halite (H), while clay minerals (chlorite – Cl, illite/mica – I/M) occur as minor phases. Detailed characterization of clay content of samples after the carbonate removal by different acids will be discussed.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

POVEZANOST RADA