hrvatski

Magnetic susceptibility measured in sediments of clean karstic and flysch rivers of Croatia and Slovenia

The aim of the present work was to perform preliminary measurements of the low-field magnetic susceptibility (MS) of sediments from several Croatian and Slovenian rivers and to find its connections with their chemical and mineralogical composition, as well as with possible anthropogenic influence. MS measurements are a new and promising fast and simple method, which could serve as a proxy for preliminary estimation of pollution in different environmental systems. As far we know it is the first time applied in the studied region. Investigated rivers are predominantly clean rivers from Croatian and Slovenian karstic and flysch areas, which belong to both Adriatic and Black Sea watersheds: Dragonja, Mirna, Raša, Rižana, Reka, Rak, Cerknišnica, Unec and Ljubljanica. It was assumed that due to their unpolluted status they could serve as a database to obtain a natural MS background for this region. For comparison with them, some rivers and a lake from the Celje old metallurgic industrial area (Slovenia) were also investigated: Savinja, Hudinja, Voglajna and Slivniško Lake. They are a sub-basin of the Sava River drainage basin. Sediments of the clean karstic and flysch rivers showed extremely low MS values, with Mass susceptibility values ranging from 0.5E-07 to 5.11E-07 and IRM values ranging from 0.7 to 7.88 A/m. In the Celje industrial area river sediments showed much higher MS values, with Mass susceptibility values ranging from 1.31E-07 to 38.3E-07 and IRM values ranging from 0.91 to 100.42 A/m. Semiquantitative determination of relations between grain-size and concentration of magnetite was performed using Thompson-Oldfield method. Our earlier research of Celje area described in details toxic contamination of river sediments with following toxic metals for which are given their maximal measured values: Zn (1040 µgg-1), Cd (7 µgg-1), Cu (138 µgg-1), Ni (82 µgg-1), Pb (133 µgg-1), Ag (3 µgg-1), Hg (1086 ngg-1) and As (30 µgg-1). Highest MS value is measured in Voglajna River at Teharje-Štore, the point which showed significant number of anomalies of toxic metals in our earlier research. XRD mineralogical analysis showed that sediments of Celje area have mostly quartz as major mineral, with relatively small amount of carbonate minerals, while in sediments of karstic rivers carbonate minerals prevail. In the present paper we discuss possible connections between measured MS values in sediments and particular metals, as well as with the mineralogical composition of sediments.

karstic and flysch rivers; Croatia; Slovenia; magnetic susceptibility; trace elements; sediments; mineralogy; anthropogenic influence

nije evidentirano

engleski

Magnetic susceptibility measured in sediments of clean karstic and flysch rivers of Croatia and Slovenia

The aim of the present work was to perform preliminary measurements of the low-field magnetic susceptibility (MS) of sediments from several Croatian and Slovenian rivers and to find its connections with their chemical and mineralogical composition, as well as with possible anthropogenic influence. MS measurements are a new and promising fast and simple method, which could serve as a proxy for preliminary estimation of pollution in different environmental systems. As far we know it is the first time applied in the studied region. Investigated rivers are predominantly clean rivers from Croatian and Slovenian karstic and flysch areas, which belong to both Adriatic and Black Sea watersheds: Dragonja, Mirna, Raša, Rižana, Reka, Rak, Cerknišnica, Unec and Ljubljanica. It was assumed that due to their unpolluted status they could serve as a database to obtain a natural MS background for this region. For comparison with them, some rivers and a lake from the Celje old metallurgic industrial area (Slovenia) were also investigated: Savinja, Hudinja, Voglajna and Slivniško Lake. They are a sub-basin of the Sava River drainage basin. Sediments of the clean karstic and flysch rivers showed extremely low MS values, with Mass susceptibility values ranging from 0.5E-07 to 5.11E-07 and IRM values ranging from 0.7 to 7.88 A/m. In the Celje industrial area river sediments showed much higher MS values, with Mass susceptibility values ranging from 1.31E-07 to 38.3E-07 and IRM values ranging from 0.91 to 100.42 A/m. Semiquantitative determination of relations between grain-size and concentration of magnetite was performed using Thompson-Oldfield method. Our earlier research of Celje area described in details toxic contamination of river sediments with following toxic metals for which are given their maximal measured values: Zn (1040 µgg-1), Cd (7 µgg-1), Cu (138 µgg-1), Ni (82 µgg-1), Pb (133 µgg-1), Ag (3 µgg-1), Hg (1086 ngg-1) and As (30 µgg-1). Highest MS value is measured in Voglajna River at Teharje-Štore, the point which showed significant number of anomalies of toxic metals in our earlier research. XRD mineralogical analysis showed that sediments of Celje area have mostly quartz as major mineral, with relatively small amount of carbonate minerals, while in sediments of karstic rivers carbonate minerals prevail. In the present paper we discuss possible connections between measured MS values in sediments and particular metals, as well as with the mineralogical composition of sediments.

karstic and flysch rivers; Croatia; Slovenia; magnetic susceptibility; trace elements; sediments; mineralogy; anthropogenic influence

nije evidentirano