Geophysical Evidence of the Collisional Suture Zone in the Prydz Bay,
East Antarctica
Abstract
The location and origin of Neoproterozoic-Cambrian sutures provide keys
to understand the formation and evolution of the supercontinent
Gondwana. The Larsemann Hills is located near a major
Neoproterozoic-Cambrian suture zone in the Prydz Belt, but has not been
examined locally by comprehensive geophysical studies. In this study, we
analyzed data collected from a 1-D joint seismic-MT array deployed
during the 36th Chinese National Antarctic Research Expedition. We found
that a sharp Moho discontinuity offset of 6-8 km shows up in the stacked
image of teleseismic P-wave receiver function analysis; coinciding with
the abrupt Moho offset, a near-vertical channel with (1) low resistivity
extending to the uppermost mantle depths, and (2) a high crustal
Poisson’s ratio in the crust is identified. These findings provide
evidence for the determination of the location and collisional nature of
the Prydz belt or a portion of it.