Sedimentation and potential venting on the rifted continental margin of Dronning Maud Land

Xiaoxia Huang,Wilfried Jokat

doi:10.1007/s11001-016-9296-x

Abstract

The relief of Dronning Maud Land (DML), formed by Middle and Late Mesozoic tectonic activity, had a strong spatial control on the early fluvial and subsequent glacial erosion and deposition. The sources, processes, and products of sedimentation along the DML margin and in the Lazarev Sea in front of the DML mountains have been barely studied. The onshore mountain belt parallel to the coast of the DML margin acts as a barrier to the transport of terrigenous sediments from the east Antarctic interior to the margin and into the Lazarev Sea. Only the Jutul–Penck Graben system allows a localized ice stream controlled transport of material from the interior of DML across its old mountain belt. Offshore, we attribute repeated large-scale debris flow deposits to instability of sediments deposited locally on the steep gradient of the DML margin by high sediment flux. Two types of canyons are defined based on their axial dimensions and originated from turbidity currents and slope failures during glacial/fluvial transport. For the first time, we report pipe-like seismic structures in this region and suggest that they occurred as consequences of volcanic processes. Sedimentary processes on the DML margin were studied using seismic reflection data and we restricted the seismic interpretation to the identification of major seismic sequences and their basal unconformities.

Highlights

The Dronning Maud Land (DML) continental margin is a rifted volcanic margin that is at present glaciated and strongly dissected by submarine canyons (Fig. 1)
The Explora Wedge, occupying much of the continental margin to the SW of Maud Rise, is a thick pile of volcanic rocks that erupted during the initial opening of the Weddell Sea (Hinz and Krause 1982; Jokat et al 2003; Hinz et al 2004)
The Middle/Late Mesozoic Jutul–Penck Graben system that cuts through the DML mountain belt seems to have allowed only limited or even zero sediment transport to the continental margin from the interior of DML, as the Fig. 10 indicates

Summary

Introduction

The Dronning Maud Land (DML) continental margin is a rifted volcanic margin that is at present glaciated and strongly dissected by submarine canyons (Fig. 1). Processes related to the evolution of this rifted margin have been intensively studied by the acquisition of seismic, gravity and magnetic data over the past three decades (Hubscher et al 1996; Roeser et al 1996; Jokat et al 2003, 2004; Hinz et al 2004; Konig and Jokat 2006). The development of submarine canyons and gravity flows are important geological factors in the transfer of large amounts of sediment onto the deeper ocean floor off continental margins (Masson et al 2006; Gales et al 2014; Huang et al 2014; Huang and Jokat 2016). The origin of the surface sedimentary processes, canyons, and their relationship with the glaciers on the DML margin are poorly studied

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