LAUSR

Abstract Quaternary carbonate-seated maar-diatremes in the Volsci Range are one of the most intriguing products of the west-directed subduction of the Adriatic slab that drove the development of the Apennine mountain belt in Central Italy. The Volsci Volcanic Field is characterized by phreatomagmatic surge deposits, rich in accidental carbonate lithics, and subordinate Strombolian scoria fall deposits and lava flows, locally sourced from some tens of monogenetic eruptive centers (at least fifty tuff rings and scoria cones). We investigate the subsurface maar-diatreme processes in terms of relationships between faulting and explosive magma-water interaction, as well as the distribution pattern of the eruptive centers. With this aim, we present the following new data: i) description of the fold-and-thrust belt structure and associated eruptive centers, ii) componentry of volcanic rock-types, iii) determination of grain-size, degrees of whiteness and roundness of carbonate lithic inclusions, iv) micropaleontological analysis of carbonate lithics. We show that the clustering of eruptive centers is controlled by tectonic features. A first order control is tentatively related to crustal laceration and deep magma injection along a ENE-trending Quaternary lateral tear in the slab and to Mesozoic rift-related normal faults. A second-order control is provided by orogenic structures (mainly thrust and extensional faults). In particular, magma-water explosive interaction occurred at multiple levels (