Geology of Montecastelli Pisano (inner Northern Apennines, Italy): normal and transfer fault zones affecting a dismantled ophiolite bearing orogenic wedge

Abstract

ABSTRACTWe present the geological map (1:10.000) of the Montecastelli Pisano area, where (i) the relationships between Neogene-Quaternary transfer and normal faults have been carefully mapped (Sheet 1), and (ii) the mantle sequence of the Ligurian Ocean has been analysed (Sheet 2). Fault analyses allowed to define: (i) NE-trending fault system (left-lateral strike- to oblique-slip faults) belonging to a transfer shear zone; and (ii) NW-trending normal to oblique-slip faults. Their evolution is framed in the extensional tectonics affecting the Northern Apennines since Early-Middle Miocene. The ophiolite complex is constituted by serpentinized spinelharzburgite with minor serpentinized dunite channels cut by gabbro dykes. A km-scale cataclastic zone cut the mantle section, locally hosting Cu-Fe mineralization. The goal of this work is to present the distribution of the main fractures affecting an area where the occurrence of ophiolite can favor the success of the CO2 reinjection project.

Keywords

• Transfer faults
• superimposed extensional structures
• serpentinite
• Ligurian ophiolite
• extensional tectonics
• Northern Apennines