Get to know the QUIN database: applications and potential insights from fault traces and over 8000 structural-geological data points in the Quaternary extensional belt of Italy

Extensional tectonics play a crucial role in shaping the morphology and structural characteristics of the Apennine chain in Italy, yet their importance has often been overlooked. Recent advancements in highlighting the significance of Quaternary extensional tectonics have been made possible by developing the QUIN database (QUaternary fault strain INdicators database). The QUIN database consists of two releases: QUIN 1.0 covering the central-northern Apennines (Lavecchia et al., 2022) and QUIN 2.0 covering the southern Apennines and Calabria (Lavecchia et al., 2024). This database provides the scientific community access to over 8000 georeferenced points related to host fault planes displaying kinematic evidence of prevailing extensional stress. The QUIN database incorporates data on fault location, attitude, kinematics, and deformation axes, mainly focusing on Fault Striation Pairs (FSPs) along Quaternary faults. Each release includes a comprehensive dataset in .shp and .txt formats and an original .shp file containing fault traces hosting the FSPs. Key information provided by the QUIN database includes: – Geographic location and geometric characteristics of fault traces – Name of fault hosting the structural sites and associated fault system – Age of the oldest recorded displacement or syn-tectonic deposits – Evidence of seismogenic or potentially seismogenic activity based on integrated geological and seismological data. The QUIN database represents a valuable resource due to its extensive coverage across the Italian peninsula, where the regional stress field has remained relatively stable over some millions of years. This stability offers a unique opportunity to analyze long-term structural data, particularly for seismic purposes, extending the investigation timeframe to encompass at least the entire Quaternary period. Such insights are critical for understanding the long-term deformation of the Apennine range, especially in areas that may have exhibited minimal seismic activity in instrumental times but could harbour significant yet unrecognized seismic potential. The applications of the QUIN database, spanning from northern Tuscany to southern Calabria, are diverse and impactful. Its comprehensive collection of fault traces in a unified database opens avenues for threedimensional seismotectonics, numerical modeling, forma stress inversion, seismic hazard assessment, and industry and territorial planning applications. Researchers interested in leveraging the QUIN database for collaborative studies are encouraged to contact us for potential collaboration opportunities.