Boron isotope geochemistry of Na-bicarbonate, Na-chloride, and Ca-chloride waters from the Northern Apennine Foredeep basin: other pieces of the sedimentary basin puzzle.

The boron stable isotope ratio δ¹¹ B of 12 water samples representative of three chemical facies (fresh Na-bicarbonate, brackish Na-chloride, saline, and brine Ca-chloride) has been analyzed. Interpretation of the δ¹¹ B data, along with the chemical compositions, reveals that Na-carbonate waters from the Northern Apennine are of meteoric origin, with boron contributions from clay desorption and mixing with seawater-derived fluids of Na-chloride or Ca-chloride compositions. The comparison of our new results with the literature data on other sedimentary basins of Mediterranean, and worldwide, confirms the contribution of Na-bicarbonate waters to the genesis of mud volcano fluids. The Na-chloride sample of Salvarola ( SAL), which may represent the end-member of the mud volcanoes, and the Ca-chloride brine water from Salsomaggiore ( SM) indicate boron release from clays compatible with the diagenetic process. The empirical equation: [ABSTRACT FROM AUTHOR]