Locating the Cambrian Suture in Wilkes Land, East Antarctica, Based on Russian Geophysical Data

Interpretation of modern aeromagnetic and radar data, primarily from Russian surveys in East Antarctica between 88°–102°E, has resulted in a tectonic map of Precambrian provinces, including two protocratonic domains and two orogens of different ages. The crust of the Charcot Province is presumably composed of Mesoarchean tonalite-gneisses of Cape Charcot (3003 ± 8 Ma), which underwent metamorphism at ~2890 Ma and a zircon-forming episode at ~550 Ma. The West Mawson protocraton province is identified based on magnetic data and is represented by terranes that may have accreted to the western edge of the East Mawson craton in the Mesoproterozoic. The Wilkes Orogen correlates with metamorphic and intrusive rocks of the Bunger Hills, Highjump Archipelago, Obruchev Hills, and exposures in the lower reaches of the Denman Glacier, mostly associated with positive magnetic anomalies forming an elongated, segmented magnetic belt. The Rayner Orogen has a heterogeneous geological structure and can be subdivided into several tectonic zones with specific lithological compositions and slightly different geological histories. All previously proposed fault locations (sutures) between Indo-Antarctica and Australo-Antarctica are not reflected in either modern aeromagnetic data or bedrock topography. Most likely, it is located along the boundary between the Charcot craton and the Wilkes Orogen and corresponds to the Northcliffe Glacier. ADMAP-2 data allow tracing its continuation towards the southern Prince Charles Mountains and/or the subglacial Gamburtsev Mountains.