East Antarctica magnetically linked to its ancient neighbours in Gondwana

Abstract

We present a new magnetic compilation for Central Gondwana conformed to a recent satellite magnetic model (LCS-1) with the help of an equivalent layer approach, resulting in consistent levels, corrections that have not previously been applied. Additionally, we use the satellite data to its full spectral content, which helps to include India, where high resolution aeromagnetic data are not publically available. As India is located north of the magnetic equator, we also performed a variable reduction to the pole to the satellite data by applying an equivalent source method. The conformed aeromagnetic and satellite data are superimposed on a recent deformable Gondwana plate reconstruction that links the Kaapvaal Craton in Southern Africa with the Grunehogna Craton in East Antarctica in a tight fit. Aeromagnetic anomalies unveil, however, wider orogenic belts that preserve remnants of accreted Meso- to Neoproterozoic crust in interior East Antarctica, compared to adjacent sectors of Southern Africa and India. Satellite and aeromagnetic anomaly datasets help to portray the extent and architecture of older Precambrian cratons, re-enforcing their linkages in East Antarctica, Australia, India and Africa.

Predicting Geothermal Heat Flow in Antarctica With a Machine Learning Approach

“…Latest during Gondwana, southern Africa, Australia, and East Antarctica were connected (Meert & Van Der Voo, 1997). Tectonic affiliations can be observed (Daczko et al, 2018;Mulder et al, 2019) and are supported by gravity and magnetic data (Aitken et al, 2016;Ebbing et al, 2021;Ferraccioli et al, 2011). Similar to Pollett et al ( 2019), we assume here that the tectonic history of these now separated continents has been relatively quiescent and that the crustal part is primarily influencing the surface heat flow in thermotectonic stable terrains (Förster & Förster, 2000;Mareschal & Jaupart, 2013).…”

“…Latest during Gondwana, southern Africa, Australia, and East Antarctica were connected (Meert & Van Der Voo, 1997). Tectonic affiliations can be observed (Daczko et al., 2018; Mulder et al., 2019) and are supported by gravity and magnetic data (Aitken et al., 2016; Ebbing et al., 2021; Ferraccioli et al., 2011). Similar to Pollett et al.…”

“…One problem arising with magnetic data is the directional dependency of the crustal field. To circumvent this, we use the magnetic field anomalies after reduction to the pole with an equivalent dipole approach (Ebbing et al., 2021).…”

High geothermal heat flow beneath Thwaites Glacier in West Antarctica inferred from aeromagnetic data

“…Therefore, the data may still be affected by diurnal variations in the geomagnetic field. All magnetic data were DC shifted to the regional long-wavelength domain of the Magnetic Field Model MF7 (https://www.geomag.us/models/MF7.html) to help homogenize the longwavelength magnetic field across different surveys 43 . In areas, where no flight lines are available we also filled data gaps with the MF7 grid (Fig.…”

An embayment in the East Antarctic basement constrains the shape of the Rodinian continental margin

“…1b) suggest that the Mawson Continent may extend through the South Pole study region. If true, a simple continuation of the linear craton margin imaged for ~2000 km from Terre Adélie to the CTAM by aeromagnetic and satellite magnetic compilations 19 might be expected. In detail, aeromagnetic and provenance data in the CTAM region suggest the presence of an in-board highly magnetic but unexposed Paleo to Mesoproterozoic subglacial igneous province 20 .…”