Petrological and Geophysical Characterization of Exhumed Subcontinental Mantle from the Australian-Antarctic Ocean-Continent Transition Zone

• Other Authors: IMAS Data Manager (publisher), Institute for Marine and Antarctic Studies (IMAS), University of Tasmania (UTAS) (hasAssociationWith), McCarthy, Anders (hasPrincipalInvestigator), Sauermilch, Isabel (pointOfContact), Sauermilch, Isabel (hasPrincipalInvestigator)
• Format: Dataset
• Language: unknown
• Published: University of Tasmania, Australia
• Subjects: geoscientificInformation; Seismic transects along Terre Adélie (East Antarctica) indicate a 50-100 km wide domain of exhumed subcontinental mantle; Seamount B likely records MORB-impregnation of subcontinental mantle at high pressures (>8 kbar); EARTH SCIENCE | SOLID EARTH | ROCKS/MINERALS/CRYSTALS; EARTH SCIENCE | OCEANS | MARINE GEOPHYSICS | MAGNETIC ANOMALIES; EARTH SCIENCE | OCEANS | BATHYMETRY/SEAFLOOR TOPOGRAPHY | CONTINENTAL MARGINS; Marine Geoscience; EARTH SCIENCES; GEOLOGY; Tectonics; Antarctic; East Antarctica; Antarctic Ocean; Terre Adélie; Terre-Adélie; Antarc*; Antarctica
• Online Access: https://researchdata.edu.au/petrological-geophysical-characterization-transition-zone/1727994

Maintenance and Update Frequency: notPlanned Statement: This Dataset contains mineral chemistry (major and trace elements) of plagioclase, olivine, spinel, orthopyroxene, clinopyroxene and amphibole from dredged samples from Seamount B (offshore Terre Adélie, Japanese dredging expeditions TH91, TH95). Credit A.M. acknowledge the support of SNSF grant P2LAP2_171819. I.S. was supported under Australian Research Council's Special Research Initiative for Antarctic Gateway Partnership (Project ID SR140300001). J.M.W. acknowledges support from Australian Research Council grant DP180102280. We are also grateful to the support from the SCAR community as well as to Dr. M. Yuasa of the Geological Survey of Japan for having carried out the initial studies on Seamount B. The seismic reflection data is freely available through the Seismic Data Library System of SCAR and geochemical analyses of minerals are accessible in the supporting information data set. The final lithospheric breakup of the Australian-Antarctic rift system remains controversial due to sparse geological constraints on the nature of the basement along the ocean-continent transition zones. We present new interpretations of multichannel seismic reflection transects, as well as new petrological data of dredged mantle rocks along the East Antarctic margin (Seamount B, offshore Terre Adélie). By combining both datasets, we show that a 50–100 km wide domain of cold (900°C), fertile subcontinental mantle was exhumed along the non-volcanic Antarctic margin. The dredged peridotites preserve characteristics similar to mantle xenoliths found in syn- to post-rift volcanism at the eastern end of the Australian margin (Victoria and Tasmania), indicating the sampling of a common fertile subcontinental mantle during rifting between Australia and Antarctica. Seamount B represents the initial stages of exhumation of cold subcontinental lithosphere along an ocean-continent transition during rifting. This thick mantle domain was likely affected by syn-rift melt ...