hrvatski

Overview of hydrogeological, geochemical and mineralogical investigations of karstic aquifers of the Biokovo Mt, Croatia

Three gravity springs which are included in the regional water supply system (Grebice, Podgorski Vrutak and Izbitac) from the slopes of the Biokovo Mt, Adriatic coast of Croatia were investigated. The aim of this paper is to give an overview of recent hydrogeological, geochemical and mineralogical investigations of watershed. The significance of performed study is particularly because such complex approach, combining several methods, is according to our knowledge used for the first time in the world karst systems to study springs. The applied combination of hydrogeological, geochemical and mineralogical methods was proved to be very useful for investigations of karstic aquifers. Hydrogeological investigations were performed during two seasons with dye tracing, using Na-fluoresceine which was poured into two pits, observing springs at distances of 1.82 – 8.8 km. Apparent velocities were 0.21 – 0.51 cms-1. Dye tracing was first time partially effective and second time ineffective, what could be due to immanent ore mineralization, which presents a natural barrier and was discovered by geochemical and mineralogical methods. Concentrations of 17 dissolved and total trace elements in spring waters were extremely low, more than 3 orders of magnitude less than allowed by the Croatian directives for the first category of groundwater and drinking water. The mass fractions of 60 elements were determined in spring sediments. From all determined elements in sediments lead had anomalous values and highest concentration was 5440 mgkg-1, which may indicate ore mineralization. Mineralogical analysis discovered and confirmed significant presence of unexpected mineral ramdohrite bismuthian, lead sulphide Ag4Pb6(Sb, Bi)11S24 what could explain extreme Pb concentrations measured in sediment samples of Izbitac and Podgorski Vrutak springs.

karstic springs; dye tracing; trace elements; sediments; mineralogy

nije evidentirano

engleski

Overview of hydrogeological, geochemical and mineralogical investigations of karstic aquifers of the Biokovo Mt, Croatia

Three gravity springs which are included in the regional water supply system (Grebice, Podgorski Vrutak and Izbitac) from the slopes of the Biokovo Mt, Adriatic coast of Croatia were investigated. The aim of this paper is to give an overview of recent hydrogeological, geochemical and mineralogical investigations of watershed. The significance of performed study is particularly because such complex approach, combining several methods, is according to our knowledge used for the first time in the world karst systems to study springs. The applied combination of hydrogeological, geochemical and mineralogical methods was proved to be very useful for investigations of karstic aquifers. Hydrogeological investigations were performed during two seasons with dye tracing, using Na-fluoresceine which was poured into two pits, observing springs at distances of 1.82 – 8.8 km. Apparent velocities were 0.21 – 0.51 cms-1. Dye tracing was first time partially effective and second time ineffective, what could be due to immanent ore mineralization, which presents a natural barrier and was discovered by geochemical and mineralogical methods. Concentrations of 17 dissolved and total trace elements in spring waters were extremely low, more than 3 orders of magnitude less than allowed by the Croatian directives for the first category of groundwater and drinking water. The mass fractions of 60 elements were determined in spring sediments. From all determined elements in sediments lead had anomalous values and highest concentration was 5440 mgkg-1, which may indicate ore mineralization. Mineralogical analysis discovered and confirmed significant presence of unexpected mineral ramdohrite bismuthian, lead sulphide Ag4Pb6(Sb, Bi)11S24 what could explain extreme Pb concentrations measured in sediment samples of Izbitac and Podgorski Vrutak springs.

karstic springs; dye tracing; trace elements; sediments; mineralogy

nije evidentirano