No abstract

Abstract. We present an innovative workflow for the statistical analysis of fracture data collected along scanlines, composed of two major stages, each one with alternative options. A prerequisite in our analysis is the assessment of stationarity of the dataset, that is motivated by statistical and geological motivations. Calculating statistics on non-stationary data can be statistically meaningless, and moreover the normalization and/or sub-setting approach that we discuss here can greatly improve our understanding of geological deformation processes. Our methodology is based on the analysis of the cumulative spacing function (CSF) and cumulative spacing derivative (CSD), that allows defining the boundaries of stationary domains in an objective way. Once stationarity has been analysed, other statistical methods already known in literature can be applied. Here we discuss in details methods aimed at understanding the degree of saturation of fracture systems based on the type of spacing distribution, and we evidence their limits in cases where they are not supported by a proper spatial statistics analysis.

Abstract. We present an innovative workflow for the statistical analysis of fracture data collected along scanlines, composed of two major stages, each one with alternative options. A prerequisite in our analysis is the assessment of stationarity of the dataset, which is motivated by statistical and geological considerations. Calculating statistics on non-stationary data can be statistically meaningless, and moreover the normalization and/or sub-setting approach that we discuss here can greatly improve our understanding of geological deformation processes. Our methodology is based on performing non-parametric statistical tests, which allow detecting important features of the spatial distribution of fractures, and on the analysis of the cumulative spacing function (CSF) and cumulative spacing derivative (CSD), which allows defining the boundaries of stationary domains in an objective way. Once stationarity has been analysed, other statistical methods already known in the literature can be applied. Here we discuss in detail methods aimed at understanding the degree of saturation of fracture systems based on the type of spacing distribution, and we evidence their limits in cases in which they are not supported by a proper spatial statistical analysis.

LiDAR and photogrammetry data are integrated to study an Early Jurassic extensional synsedimentary structure in the Italian Southern Alps. Airborne LiDAR data helped in getting geologic information in areas covered by vegetation, photogrammetry was applied to produce a high-resolution 3D textured model of the inaccessible parts of the outcrop. LiDAR and photgrammetric data were merged together producing a multi-resolution model. Key geologic boundaries and faults bounding the synsedimentary structure were digitized in a 3D geomodeling environment. The reconstruction yielded information about the structure kinematics and accumulated displacements.

The tectonic and geodynamic evolution of the Pelagian platform and of the Pantelleria Rift System, located in the foreland of the Apennine‐Sicilian‐Maghrebian Belt, from the Late Oligocene onward, is still debated. Here we present a new interpretation based on structural data collected in the Malta and Gozo islands. With a tectonic back‐stripping approach, we recognized two main extensional events separated by a period of tectonic quiescence: (D1) Early Miocene WNW‐ESE extension and (D2) Late Miocene to Pliocene N‐S extension that led to the opening of the Pantelleria Rift System. During both extensional events the Maltese Islands and the Pelagian Platform were located in the foreland of the Apennine‐Sicilian‐Maghrebian Belt (Western Mediterranean Arc), in a period of slab rollback. We suggest that both tectonic events are an evidence of the extensional regime imposed on the foreland area by the rollback of the subducting slab. The switch in the main extension axis between D1 and D2 (WNW‐ESE vs. N‐S) can be interpreted as a result of the varying orientation and distance of the trench due to the progressive development of the Western Mediterranean Arc and provides an independent tool to “monitor” the slab rollback. Results obtained in this study allowed, for the first time, to bind the tectonic evolution of the area with the geodynamic evolution of the Western and Central Mediterranean.