The geological significance of the manganese-ore mineral facies in the Miocene of the Matese Mountains (Central-Southern Apennines,Italy)

The geologic significance of the Mn-ore existing in sediments of Serravallian and/or Tortonian age of The Matese Mts. (Central-Southern Appennines) has been reinvestigated, according to more recent criteria. Such deposits originated under the influence of peculiar environments, where the instability of the sedimentary basin, preluding to greater tectonic movements, should have created conditions cyclically euxinic, very similar to those occurring in the strata located between Longano and Pietraroia Formations. Unequal tectonics acting upon Miocene sediments after their deposition, should have caused the secondary remobilisation of Mn-minerals, resulting in irregular patterns of lenses and layers of various thickness.