Impact of Tectonic, Glacial and Contour Current Processes on the Late Cenozoic Sedimentary Development of the Southeast Greenland Margin

Katrien Heirman,Antoon Kuijpers,Tove Nielsen

doi:10.3390/geosciences9040157

Katrien Heirman, Antoon Kuijpers + Show 1 more

Open Access

https://doi.org/10.3390/geosciences9040157

Copy DOI

Journal: Geosciences	Publication Date: Apr 3, 2019
Citations: 5	License type: CC BY 4.0

Affiliation: Geological Survey of Denmark and Greenland

Abstract

To understand the geomorphological contrast between the northern and southern parts of the Southeast Greenland margin with its marked differences in sedimentary regime, bathymetric and seismic reflection, data have been compiled and analysed. While previous studies focused on selected parts of this margin, the present study provides an intergraded overview of the entire margin from Cap Farewell to Denmark Strait. The prominent north–south contrast shows a wide northern shelf and a narrow southern shelf. The origin of this width disparity can be traced back to the initial formation stage of the Irminger Sea due to regional differences in uplift versus oceanic subsidence. This regional tectonic discrepancy also created a difference in sediment accommodation space that, in combination with a weak ocean circulation regime, favoured formation of Oligocene–Miocene turbidite fan complexes along the lower southern slope. These fan complexes became the core of sediment drift ridges that strike perpendicular to the slope. Strong bottom currents, which gradually increase in strength towards the south, were mainly prevalent during warmer climate stages. During glacial periods, downslope transport of glacigenic sediments and hyperpycnal meltwater flow further shaped the large drift ridges and formed several relatively narrow, V-shaped turbidite channels extending towards the deep Irminger Sea basin. These V-shaped channels are still active today when cascading dense winter water from the shelf flows downwards along the shelf to the Irminger Sea basin.

Highlights

The Southeast Greenland continental margin is marked by a northern shelf which is almost ten times wider than the shelf further south, while the steepness of the slope increases from gentle in the north to very steep in the south
Conclusions shelf edge glaciations in southern Greenland [62], which indicate the onset of oscillations in the current
An evolution model appropriate for the entire Southeast Greenland margin, and covering strengths linked to the glacial-interglacial fluctuations

Summary

Introduction

The Southeast Greenland continental margin is marked by a northern shelf which is almost ten times wider than the shelf further south, while the steepness of the slope increases from gentle in the north to very steep in the south. Deep-water currents, which vary in strength through time, transport sediment along-slope leading to the development of drift deposits, the largest of which is located off Cap Farewell and known as the Eirik Drift (Figure 1). This drift accumulated on top of a basement ridge [10], under the influence of deep-water currents originating from the North Atlantic deep-water formation regions [11,12]

Results

Discussion

Conclusion