J1-9498 — Final report
1.
Calculation of standard uncertainty of Mg geochemical thermometer in natural tufa precipitating river system

Stable isotopes of C and O, as well as elemental ratios Mg/Ca, Sr/Ca and Ba/Ca in annualy laminated tufa incrustation in the artificial tunnel were used to reconstruct the conditions of carbonate precipitation from the groundwater-fed river. We calculated the standard uncertainty of the Mg thermometer, determined the contribution of individual parameters and estimated the sources of uncertainty of commonly used isotope thermometer. The conservative standard uncertainties exceeded the influence of natural variability of both ?18O and Mg/Ca ratio.

COBISS.SI-ID: 22294055
2.
Analysis of behaviour of major, minor and trace elements of anthropogenic origin in karstic water systems

The paper deals with hydraulic behaviour of a karstic aquifer, as well as mass and solute transport within the aquifer. The utmost importance of the epikarstic zone is stressed in the process of recharge and discharge of groundwater, and in mechanisms influencing the local water flow and mass transport. The results can be transferred to other karstic environments around the world, and contribute to the methodology of evaluation of vulnerability of karstic aquifers and strategies of their management and protection, as well as for solving engineering problems.

COBISS.SI-ID: 1541717
3.
The use of isotopic fingerprints of organic matter of terrigenic and riverine origin for analysis of its behaviour in natural aquatic sediments

Using granulometrical, mineralogical, elemental and isotopic analysis of the sediment, the distribution of riverine component of the sediment in a karstic estuary was studied. Main water-sediment interactions were described, influencing the precipitation of mineral phases and transformation of organic matter. Stable isotopes were applied to estimate the fraction of terrigeneous mineral and organic matter and its distribution in the estuary, as well as the anthropogenic influence on the quality, quantity and origin of sedimentary organic matter.

COBISS.SI-ID: 22048807
4.
Conditions for phase transition of aragonite into calcite in karstic aquatic sediments

Conditions for the preservation of recent aragonite-rich sediments during early diagenesis in Mediterranean karstic seawater lakes were examined. A decrease in sedimentary carbonate ?13C values with depth indicated transfer of biogenic C into the carbonate pool by recrystallisation, masking changes in ?13C caused by increasing amounts of aragonite. Irrespective of high supersaturation of pore water with respect to calcite, carbonate dissolution occured locally; as Mg-calcite accounted for most of the carbonate dissolution, aragonite preservation in the sediment is favoured.

COBISS.SI-ID: 23406119
5.
Analyisi of geochemical and isotopic profiles of tufa incrustation formed in controlled conditions in an aqueduct

Stable isotope composition of carbonate in the laminar crust, precipitated during last 140 years in the El Tempul Aqueduct near Cadiz (Spain) was studied. Main temporal trends in ?13C and ?18O were determined and compared to the available historic archive hydrometeorological data. The observed trends did not match the measured temperature records; this discrepancy is interpreted in terms of variable precipitation rate of carbonate.

COBISS.SI-ID: 22310183