Crustal Structure, Tectonic Subsidence, and Lithospheric Stretching of the Princess Elizabeth Trough Basin, East Antarctica

Abstract

This paper considers crustal structure, seismic stratigraphy, thermal evolution and lithospheric stretching of the deep-water basin located on the East Antarctic passive margin in the Princess Elizabeth Trough. Seven of the Middle Jurassic to Quaternary seismic sequences was identified based on interpretation of multichannel seismic data. The information about seismic stratigraphy and crustal thickness (calculated from gravity data) along the section crossing the Princess Elizabeth Trough was used for numerical modeling of the thermal regime of the lithosphere, tectonic subsidence of the crystalline basement and lithospheric stretching. Modeling shows that calculated tectonic subsidence is possible only under the assumption of crustal extension before the deposition (during the crustal doming at the early rift phase). Maximum stretching factor in the basin ranges from 1.1 to 2.0 for the period which preceded the deposition and 2.8 for the period of the rift-related deposition.