Evincing the presence of a trans‐Gondwanian mobile belt in the interior of the Princess Elizabeth Land, East Antarctica: insights from offshore detrital sediments, rock fragments, and monazite geochronology

Abstract

East Gondwana was assembled through the stitching of the Indo‐Antarctica and Australo‐Antarctica domains which also represents the key Gondwana‐forming regions in present‐day East Antarctica. However, the Indo‐Antarctica and Australo‐Antarctica boundaries remain speculative and contentious, as the thick Antarctic Ice sheet precludes direct geological characterization of these terranes. In addition, the exact role of the Gamburtsev Subglacial Mountains, present in the interior of Princess Elizabeth Land (PEL), during the amalgamation of Gondwana, has not been well understood. We present new mineralogical data of offshore sediments from Prydz Bay to infer the geology of the interior of the PEL terrain, East Antarctica. Coast marginal outcrops dominantly expose igneous and granulite facies metamorphic rocks. Heavy minerals characterization of the rock fragments followed by consideration of the outcrop geology indicate a possible contribution of sediments from the far interior of PEL terrain. Total U–Pb chemical geochronology of detrital monazites dominantly shows a bimodal age distribution ascribable to Stenian to Tonian (~1,100 Ma, 900 Ma) event ages and a younger Pan‐African event (~500 Ma). Besides these, Tonian‐Cryogenian (~700 Ma) ages from texturally constrained monazites of a low‐grade schist rock fragment is reported for the first time from this sector. Consideration of glacial flow directions and the nature of rock fragments indicate their sourcing from the distal hinterland. The possible provenance is inferred to be from the Gamburtsev Subglacial Mountains.