The foreland-propagating thrust architecture of the East Greenland Caledonides 72°–75°N

Abstract

Systematic geological mapping of the East Greenland Caledonides demonstrates that the orogen is built up of WNW-directed thrust sheets displaced across foreland windows. The foreland windows in the southern half of the orogen are characterized by a thin (220–400 m) Neoproterozoic to Lower Palaeozoic succession, structurally overlain by two major Caledonian thrust sheets (Niggli Spids and Hagar Bjerg Thrust Sheets). The metasediments of the upper-level Hagar Bjerg Thrust Sheet host 940–910 Ma granites and migmatites formed during an early Neoproterozoic thermal or orogenic event, as well as Caledonian 435–425 Ma granites and migmatites. The uppermost unit of the thrust pile, the Franz Joseph Allochthon, comprises a very thick (18.5 km) Neoproterozoic to lower Palaeozoic sedimentary succession (Eleonore Bay Supergroup, Tillite Group, Kong Oscar Fjord Group). Total westward displacement of the thrust sheets was about 200–400 km, with shortening estimated at 40–60%. Major extensional faults post-date thrusting. Restoration of the thrust sheets indicates that the sequence of Caledonian orogenic events now preserved in East Greenland was initiated several hundred kilometres ESE of present-day East Greenland, as Baltica and its marginal assemblage of Early Palaeozoic accretions began to impinge on the Laurentian margin.

CRUSMID-3D: Crustal Structure and Mineral Deposit Systems

“…The sequence was widely deformed by N-S syn-sedimentary open folding, westward thrusting and by uplift. Transtensional pull-apart basins started to form in Middle to Late Devonian with large scale ESE-WNW extensional faulting that displaced the Caledonian thrust units north of Kong Oscar Fjord (Higgins et al, 2004), and N-S directed sinistral wrench faulting (Larsen and Bengaard, 1991). The stress pattern shifted from oblique to a more orthogonal rifting in latest Devonian leading in late Carboniferous-early Permian to rotational block faulting along the new half graben basin margins (Fig.…”

Metallogeny of Greenland

“…21). The orogen formed by the collision of Laurentia and Baltica, and the rocks in the up to 300 km wide belt in Greenland are derived from the eastern Laurentian margin (Higgins et al, 2000;Higgins et al, 2004;Higgins and Leslie, 2008;Higgins, 2015). The autochthonous foreland in the west is only preserved in Kronprins…”

Identification of a Robust Lichen Index for the Deconvolution of Lichen and Rock Mixtures Using Pattern Search Algorithm (Case Study: Greenland)

“…The geology of central East Greenland is dominated by the N-S orientated Caledonian Fold Belt formed by the collision between Laurentia and Baltica 465-400 million years ago (Higgins et al, 2004). Liverpool Land forms a c. 3500 km 2 horst of Caledonian crystalline rocks separated from the postCaledonian Jameson Land sedimentary basin to the west by a major N-S-oriented fault zone.…”