  We present a detailed map of the uranium distribution and its uncertainties
in the Variscan Basement of Northeastern Sardinia (VBNS) at a scale 1:100,000.
An area of 2100 km2 was investigated by means of 535 data points obtained from
laboratory and in situ gamma-ray spectrometry measurements. These data volume
corresponds to the highest sampling density of the European Variscides, aimed
at studying the genetic processes of the upper crust potentially triggered by
an enrichment of radiogenic heat-producing elements. For the first time the
Kriging with Variance of Measurement Error method was used to assign weights to
the input data which are based on the degree of confidence associated to the
measurements obtained with different gamma-ray spectrometry techniques. A
detailed tuning of the model parameters for the adopted Experimental
Semi-Variogram led to identify a maximum distance of spatial variability
coherent to the observed tendency of the experimental data. We demonstrate that
the obtained uranium distribution in the VBNS, characterized by several
calc-alkaline plutons emplaced within migmatitic massifs and amphibolite-facies
metamorphic rocks, is an excellent benchmark for the study of 'hot' collisional
chains. The uranium map of VBNS, and in particular the Arzachena minor pluton,
confirms the emplacement model based on the recognition of the different
petrological associations characterizing the Variscan magmatic processes in the
Late Paleozoic. Furthermore, the presented model of the uranium content of the
geological bedrock is a potential baseline for future mapping of radon-prone
areas.
