Sediment supply on the West Greenland passive margin: redirection of a large pre-glacial drainage system

Abstract

The Mesozoic–Cenozoic separation of Greenland and North America produced the small oceanic basins of the Labrador Sea and Baffin Bay, connected via a complex transform system through the Davis Strait. During rifting and partial breakup sedimentary basins formed that record the changing regional sediment supply. The onshore and offshore stratigraphy of Central West Greenland outlines the presence of a major fluvial system that existed during the Cretaceous and was later redirected in the Early Cenozoic by the formation of the West Greenland Igneous Province. Hydrological analysis of Greenland's isostatically balanced basement topography outlines two major drainage systems that likely flowed across Greenland prior to the onset of glaciation and emptied into the Sisimiut Basin within the Davis Strait, offshore West Greenland. The course of the northern drainage system suggests that it initially flowed NW into the Cretaceous/Palaeocene Nuussuaq Basin, before being redirected SW around the West Greenland Igneous Province in the Mid-Palaeocene. Moreover, characteristics of these two drainage systems suggest they acted as a single larger fluvial system, prior to the onset of glaciation, that was likely the primary source of sediment across Central West Greenland throughout the Cretaceous and Palaeogene. This scenario provides a greater understanding of the West Greenland margin's late Cenozoic evolution, which differs from previous interpretations that hypothesize a period of considerable post-rift tectonism and uplift. This work highlights the importance of large pre-glacial drainage systems across North Atlantic passive margins and their relevance when studying post-rift stratigraphy in rifted margin settings.Supplementary material: Isostatic modelling, hydrological analysis and chi mapping is available at: https://doi.org/10.6084/m9.figshare.c.5050146

Paleocene-Eocene volcanic segmentation of the Norwegian-Greenland seaway reorganized high-latitude ocean circulation

“…4). This is similar to the volcanically deflected Paleocene-Eocene deltaic deposits on the West Greenland margin 48,49 and Supplementary Note 2). The cored succession formed in a storm-and wave-influenced shallow marine environment (Fig.…”

Geologic Provinces Beneath the Greenland Ice Sheet Constrained by Geophysical Data Synthesis

“…Foremost is the modern context it provides for new applications of existing methods (e.g., interpretation of new seismic, gravity or magnetic data sets), evaluation of aerogeophysical data sets beyond those we considered, or tracing the provenance of offshore sediments (e.g., White et al., 2016). Another application could be exploring relations between these apparent province boundaries and other subglacial properties of geophysical, glaciological, geomorphological or geochemical interest, such as geothermal heat flow (Jones et al., 2021), bedrock erodibility (Campforts et al., 2020), basal friction (Maier et al., 2022), drainage history (Jess et al., 2020; Keisling et al., 2020), or isotope geochemistry (Briner et al., 2022; Colville et al., 2011). While our results were based on conventional manual delineation of province boundaries and interpretation, machine learning techniques could also be applied to reveal such structures with reduced influence from expert biases (e.g., Colgan et al., 2022; Li et al., 2022; Rezvanbehbahani et al., 2017).…”