Determining the lithogeochemical background concentrations of 39 elements in Bavarian rocks

Abstract

An approach is presented to establish a state-wide basis for geochemical background values from the available data of the Geological Survey of Bavaria. For this purpose, typical element background concentrations of rock units in Bavaria were statistically evaluated and presented in a lithogeochemical map derived from the geological map at a scale of 1:25,000. The elements comprise 39 geogenic main and trace elements (SiO2, Al2O3, Fe2O3, MnO, MgO, CaO, Na2O, K2O, TiO2, P2O5, Li, Be, Sc, V, Cr, Co, Ni, Cu, Zn, Ga, As, Rb, Sr, Y, Zr, Nb, Mo, Cd, Sn, Sb, Cs, Ba, La, Ce, Tl, Pb, Bi, Th, and U). The distributions of element concentrations in the lithogeochemical units follow closely lognormal patterns in a large majority of cases. Statistical parameters (10th, 25th, 50th, 75th, 90th percentiles) of investigated elements were determined using the cenfit function of the NADA package in the open-source R program. The investigation, based on 8,838 analysed samples, provided data for about 2/3 of the area of Bavaria. The lithogeochemical map with medians (50th percentiles) and background values (90th percentiles) of the investigated elements is available in a web map application. Thus, the regional geogenic background values of the investigated elements in Bavaria are publicly available for a large variety of applications, such as environmental issues and applied research questions.