The relationship between Caledonian nappe tectonics and Silurian turbidite deposition in North Greenland

Abstract

The relationship between the northern part of the Caledonian fold belt of East Greenland and the North Greenland fold belt is explored within the context of Silurian sedimentation and tectonics. A model is developed relating the Caledonian nappes of eastern North Greenland to major tectonic and sedimentological features of the Silurian of the remainder of North Greenland. The abrupt change from a thin succession of predominantly slowly deposited muds to a thick succession of rapidly deposited sandstone turbidites at the Ordovician/Silurian boundary, in the deep-water basin N of the carbonate platform in North Greenland, is directly related to uplift and westerly directed nappe emplacement in the eastern Caledonides. It is suggested that uplift to the E of North Greenland, which commenced in the late Ordovician or early Silurian, provided the main source of the Silurian turbidites of North Greenland. This is corroborated by the dominant westerly transport direction of the Silurian turbidites. Nappe emplacement during the latest Llandovery (Silurian), and foundering of the whole of the carbonate platform of eastern North Greenland E of the Victoria Fjord Arch (approximately 60 000 km 2 ), is marked by the replacement of shallow water carbonates by basin turbidites. These events were directly related to isostatic readjustments as the nappes advanced onto the eastern fringe of the platform.

Depositional environments along a carbonate ramp to slope transition in the Silurian of Washington Land, North Greenland

“…20). 1980;Hurst and Kerr 1982;Hurst et al 1983;Hurst and Contemporaneously, reefs developed at the carbonate Surlyk 1982;Surlyk and Hurst 1982) allow environment ramp margin and on the slope, the latter stratigraphically reconstruction within the context of a comprehensive above lime-mudstone-dominated initial slope associaframework.…”

The Timing of Strike-Slip Deformation Along the Storstrømmen Shear Zone, Greenland Caledonides: U–Pb Zircon and Titanite Geochronology

“…A foreland foldand-thrust belt developed in the Paleozoic sequence marks the westernmost extent of Caledonian deformation. The influx of Silurian turbidites onto the Laurentian carbonate platform and their involvement in the thrust belt, with truncation of strata as young as Wenlock, are cited as evidence for the onset of the collision between Baltica and Laurentia (Hurst et al 1983;Rasmussen and Smith 2001); however the timing of thrusting in the foreland is not well known.…”

Plagioclase replacement textures in partially eclogitised gabbros from the Sanddal mafic‐ultramafic complex, Greenland Caledonides

“…The Palaeoproterozoic to Mesoproterozoic sequence and the overlying Palaeozoic passive margin are imbricated in a west vergent, foreland fold‐and‐thrust belt beneath the thick‐skinned Nørreland thrust sheet. The youngest strata cut by thrusts in North‐East Greenland are Lower Silurian siltstones and shales of the Profilfjældet Member of the Lauge Koch Formation (Hurst & Surlyk, 1982; Hurst et al ., 1983). These Silurian sediments have been interpreted as turbidites being shed into a foreland basin and thus give an indication of even earlier thrusting.…”