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Schirmacher Oasis and Bharati Promontory in Larsemann Hills of East Antarctica are currently ice-free coastal areas exposed in physiographically different polar periglacial environments. Schirmacher Oasis is bound by the presence of a vast stretch of ice shelf in the north and the polar ice sheet in the south. It exhibits well-developed patterned ground, abundant till deposition, block-fields, episodic development of curvilinear morainic ridges, extensive outwash plains and erratics. In contrast, the occurrence of such depositional features is sparse on Bharati Promontory, where landmass is directly in contact with the ocean. The sedimentary processes vary in their magnitude owing to different physiographic settings in these two geographically separated locations. Scanning electron microscopy of quartz grains shows subsequent reworking under glaciofluvial environment and final deposition of material in glacially scoured basins. The fluvial action is more pronounced in the Schirmacher Oasis than on Bharati Promontory. The transport of sediment by polar ice is mainly through englacial pathways with a minor contribution from the supraglacial component. Discharge of all sizes of sediments ranging from large boulders to glacially abraded rock-flour in varying proportions takes place at the ice–bedrock interface. Granulometric analysis also shows turbulence of transporting media and reworking of sediments before final deposition.

The Grubergebirge anorthosite, a Late Neoproterozoic massif-type anorthosite, was emplaced into Late Mesoproterozoic-aged metamorphosed orthogneisses and supracrustal rocks in the Wohlthat Mountains. Mineralogically and chemically, the marginal rocks to the anorthosite massif classify as ferromonzodiorite and ferromonzonite. Variations in trace and rare earth element abundances and normalized patterns between the anorthosite and associated marginal ferromonzodiorite (and minor ferromonzonite) and distinct differences between the ferromonzodiorite and ferromonzonite have been observed. Whereas the magmas from which the anorthosite crystallized have been slightly contaminated by incorporating crustal material (now occurring as enclaves), the marginal ferromonzodiorite represent rocks that originated due to mixing (hybridization) of injected primitive ferrodiorite magma(s) with preexisting crustal material, resulting in the hybrid ferromonzodiorite.These events at the margin of the massif anorthosite represent a widespread Late Neoproterozoic magmatic event with accompanying crustal mixing; all these rocks were thereafter metamorphosed under amphibolite-to granulitefacies conditions during the Early Cambrian Period. In contrast, unmetamorphosed dykes with a ferrodiorite mineralogy, of Late Cambro-Ordovician age, have been found that probably represent a part of the late magmatic suites of the south Petermannketten (Zwiesel).

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The 600–660 Ma East African Orogen (EAO) granulites of the Mozambique Belt were correlated and extended into a coast marginal area of East Antarctica through the NNW–SSW-trending granulite-bearing Schirmacher Oasis. Tracing similarities in lithological association, granulite-facies metamorphism and geochronological data, the 640 Ma EAO was extended by another 110 km south of Schirmacher into the Humboldt Mountains in central Dronning Maud Land (cDML). Based on younger anorogenic magmatism east and west of the Humboldt Mountains, a 10–20 km-wide linear corridor of the EAO from the Schirmacher to the Humboldt Mountains was proposed.There are eight nunataks between Schirmacher and the Humboldt Mountains projected above the ice sheet. These nunataks are strategically placed because they represent the small (4–10 km2), isolated rock exposures in approximately 5000 km2 of ice-covered area. Baalsrudfjellet is one of these nunataks that is located at the easternmost margin of the proposed EAO corridor and represents a significant outcrop to validate the presence of the EAO between Schirmacher and the Humboldt Mountains. This study brings out a two-stage metamorphic evolution (c. 660–680 Ma and c. 580 Ma) with melt generation associated with the younger event. Geochronological constraints by monazite chemical dating from metapelites confirm and validate the continuation of the EAO in-between the Schirmacher Oasis and the Humboldt Mountains.Supplementary material: Monazite analyses, computed ages and age errors of three grains from the high- and low-melt metapelite are available at https://doi.org/10.6084/m9.figshare.c.3738362