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

We 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.

Automated summary

The paper presents a geological map (1:10,000) of the Montecastelli Pisano area, mapping the relationships between Neogene-Quaternary transfer and normal faults (Sheet 1) and analyzing the mantle sequence of the Ligurian Ocean (Sheet 2). The fault analyses revealed a NE-trending fault system belonging to a transfer shear zone and NW-trending normal to oblique-slip faults. These faults are a result of extensional tectonics affecting the Northern Apennines since the Early-Middle Miocene. The ophiolite complex in the area consists of serpentinized spinelharzburgite with minor serpentinized dunite channels and gabbro dykes. The study aims to highlight the distribution of main fractures in an area with ophiolite occurrences, which could benefit CO2 reinjection projects.