Borexino is a 280-ton liquid scintillator detector located at Laboratori Nazionali del Gran Sasso (Italy) measuring geoneutrinos from 238U and 232Th decay chains through inverse beta decay of free proton. The improved geoneutrino analysis of some 3263 days of data, taken by Borexino between December 2007 and April 2019, is candidate to provide useful insights into the composition of the Earth’s interior as well as into its radiogenic heat budget.
We present the geological implications of the geoneutrinos signal results through a comparison with the predictions of different Bulk Silicate Earth models. Based on the knowledge of abundances and distributions of U and Th in the lithosphere, the mantle signal is extracted from the spectral fit of the Borexino measurement. Considering different scenarios about natural radioactivity in the deep Earth, the measured mantle geoneutrino signal has been converted to radiogenic heat. The convective Urey ratio is also extracted adopting the total radiogenic heat estimation. Finally, constraints on lower limits of U and Th abundances in the mantle are reported.