Naslov
Record of anthropogenic (urban) pollution in sediments of the karst lake Modro jezero, Croatia

Autori
Hasan, Ozren ; Miko, Slobodan ; Ilijanić, Nikolina ; Stroj, Andrej

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

Izvornik
20th International Karstological School “Classical Karst” ; Karst Forms and Processes, Guide Book & Abstracts / Mihevc, Andrej ; Gabrovšek, Franci - Postojna : Karst Research Institute - ZRC SAZU, 2012, 55-56

Skup
20th International Karstological School “Classical Karst”

Mjesto i datum
Postojna, Slovenija, 18.06.2012. - 22.06.2012

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Urban pollution; karst lake; Modro jezero; magnetic susceptibility

Sažetak
Modro jezero (Blue Lake) is a karst lake formed as a collapse doline. A Lake was probably formed, together with a neighboring Crveno jezero, at the edge of a late Miocene lake. It is surrounded by the the town Imotski located in Dalmatia, southern Croatia. The wider area is inhabited since Neolitic. During the 9th century AD a fortress was built at the edge of a lake’s steep southeastern slopes. A highest edge of a lake is at 527 m a.s.l., and the lowest at 385 m a.s.l. It is 350 x 920 m wide, with very steep, almost vertical northwestern and southeastern slopes. Other slopes are less steep. A lake bottom is located at 242 m a.s.l., and is 195 x 75 m wide. The highest recorded water level was at 345 m a.s.l. Through the 20th century the lake has dried out 7 times. The drought period, which started in summer 2011, provided the access to the lake bottom, and therefore a possibility for a drilling campaign, performed in January 2012. A 8, 2 meter long undisturbed sediment core was extracted from a Lake bottom using a Eijkelkamp percussion drilling equipment. Preliminary analyses of magnetometric susceptibility, mineralogical and chemistry measurements were performed on sediment samples. Bulk mineral analysis of surface sediments showed that they are highly calcareous. They are mainly composed of high- and low-Mg calcite. The highest magnetic susceptibility was measured in a 10 cm thick red clay layer at the depth of 30 cm, which corresponds probably to the activities when access walking paths were made to the lake waterfront. The increased values gradually drop down core to the depth of 1, 30 m indicating anthropogenic activity and soil erosion in the catchment. The rest of the sediments show low magnetic susceptibility, characteristic for carbonate/calcite rich lake sediments.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

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