Geophysical Evidence of the Collisional Suture Zone in the Prydz Bay, East Antarctica

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 one-dimensional (1D) 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 (a) low resistivity extending to the uppermost mantle depths, and (b) 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. Our study seeks to unravel the history of a supercontinent called Gondwana. We do this by exploring ancient geological features known as sutures. These sutures are like stitches that hold the Earth's crust together, and they're crucial in understanding how continents were once connected. We specifically focused on a place in Antarctica called the Larsemann Hills, which is located near an important suture zone. This region hasn't received much attention from scientists until now. During the 36th Chinese National Antarctic Research Expedition, we made some exciting discoveries. We found a clear boundary in the Earth's crust, a bit like a seam in a piece of clothing. At the same time, we noticed a unique underground pathway. This pathway had special properties, suggesting that it reaches deep into the Earth's mantle. It's a bit like finding a hidden treasure beneath the Earth's surface. Our findings strongly suggest a connection between these underground discoveries and the ancient sutures in the Earth's crust. In other words, we're piecing together a puzzle that can help us learn more about the Earth's past and how continents have moved over millions of years. A distinct Moho discontinuity offset of 6-8 km is found in the stacked image obtained from P-wave receiver functionIn conjunction with the abrupt Moho offset, a nearly vertical conduit with low resistivity and high Poisson's ratio is identifiedThese geophysical results provide crucial evidence for determining the collisional nature and location of the Prydz orogenic belt