Polyphase deformation at the Harder Fjord Fault Zone (North Greenland)

Abstract

In North Greenland, the E-W-trending Harder Fjord Fault Zone represents a major lineament which cuts through Cambrian to Silurian deep-water sediments of the Franklinian Basin over a distance of 300 km. On both sides of the fault zone, these successions were affected by two stages of folding (F1, F2) during Devonian to Early Carboniferous (Ellesmerian) deformation. No field evidence was found that the Harder Fjord Fault Zone was active prior to Ellesmerian folding. Early movements along the fault zone are indicated by post-Ellesmerian sedimentation of coarse red-beds (Depot Bugt conglomerate) which represent the oldest of the Wandel Sea Basin sediments. They were probably deposited in narrow, fault-controlled (?)Late Carboniferous basins similar to those described from Svalbard. During Late Cretaceous times, 500 m thick fluvial and marine clastic sediments were unconformably deposited over the folded Cambro-Ordovician units. Although no direct field evidence suggests that sedimentation was controlled by displacements along the Harder Fjord Fault Zone, the intrusion of Upper Cretaceous mafic sills and dykes indicates a phase of important crustal extension related to reactivation of the fault zone during this period of time. This stage was followed by post-late Santonian (Eurekan) N-S compression (D3) which affected the Franklinian Basin deposits, Wandel Sea Basin sediments and mafic intrusions. In general, it was concentrated along the Harder Fjord Fault Zone and probably caused the reactivation of pre-existing (?)Carboniferous and younger fault lines. The entire deformation and its timing are comparable with the Eurekan structures found at the Kap Cannon Thrust Zone in northernmost Greenland and are related to intracontinental compression prior to the separation of Svalbard from Greenland.

Eurekan transpressive deformation in the Wandel Hav Mobile Belt (northeast Greenland)

“…In north Greenland, Eurekan structures are concentrated along the Kap Cannon Thrust Zone Soper and Dawes, 1970;Dawes, 1971;Brown and Parsons, 1981;Soper et al, 1982;Higgins, 1987, 1991b;von Gosen and Piepjohn, 1999], the Harder Fjord Fault Zone [e.g., Håkansson and Pedersen, 1982;Higgins, 1984;Piepjohn and von Gosen, 2001], and the Wandel Hav Mobile Belt (Figure 3) which is the subject of the present paper.…”

“…Proterozoic to Late Cretaceous sequences are crosscut by NW-SE trending fault lines within the entire belt. Deposition of Late Paleozoic strata was accompanied by fault tectonics [Håkansson and Stemmerik, 1984; Stemmerik and Håkansson, 1991;Stemmerik et al, 1994;, and related displacements along the Harder Fjord Fault Zone are reasonable [e.g., Håkansson and Pedersen, 1982;Piepjohn and von Gosen, 2001].…”

Tectonic map of the Ellesmerian and Eurekan deformation belts on Svalbard, North Greenland, and the Queen Elizabeth Islands (Canadian Arctic)

“…Results of structural analyses at the fault zone, however, argue for a compressional tectonic regime with transport directions to the north as well [50].…”

3D restoration of a Cretaceous rift basin in Kilen, eastern North Greenland

“…1; Håkansson et al, 1981;, and shares a common geological history with basins in Arctic Canada, Svalbard and the western Barents Sea (Soper et al, 1982;Piepjohn & von Gosen, 2001;Gosen & Piepjohn, 2003;Stemmerik & Worsley, 2005;Piepjohn et al, 2015Piepjohn et al, , 2016.…”

“…1; Stemmerik et al, 2000). In pre-Atlantic opening times, these faults were parallel to the Billefjorden and Lomfjorden fault zones on the conjugate Svalbard margin (Soper et al, 1982;Faleide et al, 1993;Piepjohn & von Gosen, 2001;Gosen & Piepjohn, 2003;Leever et al, 2011). and Stemmerik et al (2000) with schematic faults from Kilen modified from Svennevig et al (2016a).…”