Fault-related fractures of the Rennick-Aviator shear zone (north Victoria Land, Antarctica): insight to infer the paleo fluid circulation.

North Victoria Land (NVL), located at the Pacific-Southern Ocean termination of the Transantarctic Mountains (TAM), presents a complex architecture deriving from a long-lasting tectonic evolution. After the Paleozoic juxtaposition to the East Antarctic craton, NVL was affected by i) the Gondwana breakup which led to the Meso-Cenozoic rifting-drifting between Antarctica and Australia, ii) the rifting in the Ross Sea, iii) the uplift of the TAM and iv) the SE prosecution of the kinematics that characterize the spreading of the Southern Ocean (e.g., Tasman and Balleny Fracture Zone). Regionally sized, crustal scale faults crosscut VL from the Southern Ocean to the Ross Sea and represent Paleozoic inherited weakness zones that have been reactivated several times until Recent. These are both firstorder faults, which separate different crustal blocks (from W to E, the Wilson, Bowers, and Robertson Bay terranes), and second-order faults that cut through homogeneous lithotectonic units. This long-lived tectonic history produced zones of intense deformations, often accompanied with fluid circulations (e.g., Malatesta et al., 2021) and exhumation of deep shear zones. In this work we present preliminary results of the analysis of fractures associated to the Rennick-Aviator km-scale fault corridor. Specifically we explore the intensity of brittle deformation, its spatial distribution and relation with the regional faults aimed to quantify the spatial variation of the hydraulic properties (e.g., secondary permeability) of the damage zones. Moreover, fault and fracture inversion for paleostress computation is applied to infer the most permeable fracture population (e.g., fracture kept open from the acting paleostress that increases the secondary permeability in a specific direction and thus enhance fluid circulation along preferential pathways). In NVL various fault zones are characterized by hydrothermal mineral alteration (e.g., Crispini et al., 2011; Malatesta et al., 2021) this study represents the basis to identify the main fluid pathways and to estimate the rock volume affected by hydrothermal fluid circulation.