Geodatabase of structural data from North Victoria Land (Antarctica): a useful tool for geodynamic modelling

Here we present an open access GIS project associated to a structural database which includes the geo-structural measurements (over 6000) collected in the field during the past Italian PNRA (National Antarctic Research Program) scientific expeditions from the year 1988 to 2021. The targeted research area is the North Victoria Land (NVL), Antarctica, between the 70°-76° S latitude and the 159°-171° E longitude.

NVL is an area difficult to be accessed for direct geological studies on rocks due to the extensive ice/snow coverage (~5%) and few published studies with complete structural datasets are available so far.

Our database is organized in various fields which include: number/code of the expedition, date, code of the site of field structural measurement, geographical coordinates of the field measurement site, elevation, toponyms, lithological classification, geological unit, description of any collected sample, name of the field data collector, classification, attitude of measured structural element (strike/trend, dip/plunge, dip/plunge direction), local magnetic declination at the date of the field survey.  Fault attributes include fault type (normal, reverse, strike-slip), rake of the slickenlines and sense of motion. Attributes of the extensional fractures/joints also include their dimension (height, H) and spacing (S).

Moreover, the GIS project includes basic georeferenced maps such as: i) geological maps of NVL available in literature at 1:250.000 and 1:500.000 scale; ii) DEM of the bedrock and of the ice surface (from Bedmap 2); iii) the Radarsat mosaic of Antarctica; and iv) the MODIS mosaic of Antarctica.

This queryable database allows to perform multiple geostatistical analyses and realise geothematic maps such as: i) the spatial variability of the main azimuthal structural trends at the regional scale; ii) the intensity of brittle deformation quantified by the H/S parameter (see contribution of Cianfarra et al. in this meeting); and iii) thematic geostructural maps (e.g: maps of the foliation traces, of strain partitioning or fractures distribution).

These analyses, pivotal to better understand the tectonic framework of complex regions such as the NVL and to provide constraints supporting any geodynamic modelling, will greatly benefit from the extreme pliability and interoperability of such a database, which can be easily modified and expanded according to different scientific research needs by the production of newly derived data.