Thermo-tectonic development of the Wandel Sea Basin, North Greenland

Abstract

The Carboniferous–Palaeogene Wandel Sea Basin of eastern North Greenland (north of 80°N, east of 40°W) is an important piece in the puzzle of Arctic geology. It is particularly important for understanding how the Paleocene–Eocene convergence between Greenland, the Canadian Arctic and Svalbard relates to the compressional tectonics in the High Arctic, collectively known as the Eurekan Orogeny. In this study, we present apatite fission-track analysis (AFTA) data and review published vitrinite reflectance data combined with observations from the stratigraphic record to place firmer constraints on the timing of key tectonic events. This research study reveals a long history of episodic burial and exhumation since the collapse of the Palaeozoic fold belts in Greenland. Our results define pre-Cenozoic exhumation episodes in early Permian, Late Triassic, Late Jurassic and mid-Cretaceous times, each involving the removal of kilometre-scale sedimentary covers. Mid-Paleocene exhumation defines the timing of compression along the major fault zones during the first stage of the Eurekan Orogeny, after the onset of sea-floor spreading west of Greenland. Regional exhumation that began at the end of the Eocene led to the removal of most of a kilometre-thick cover that had accumulated during Eocene subsidence and involved a major reverse movement along the Harder Fjord Fault Zone, northern Peary Land. These events took place after the end of sea-floor spreading west of Greenland, and thus, represent post-Eurekan tectonics. Mid–late Miocene exhumation is most likely a consequence of uplift and incision across most of the Wandel Sea Basin study area. The preserved sedimentary sequences of the Wandel Sea Basin represent remnants of thicker strata that likely extended substantially beyond the present-day outline of the basin. We find that the present-day outline of the basin with scattered sedimentary outliers is primarily the result of fault inversion during Eurekan compression followed by deposition and removal of a kilometre-thick overburden.

Shallow Thermal Anomalies and Their Role in the Breakup Evolution Along the Conjugate Margins of the Fram Strait (Svalbard and Eastern North Greenland), Indicated by Low‐Temperature Thermochronology

“…In North Greenland, we sampled two sites on Prinsesse Thyra Island, one site on Prinsesse Margrethe Island, and several locations at Nakkehoved, including specimens of the quartz veins (Figures 2a, Table S1 in Supporting Information S1). Unlike previous descriptions in the literature (e.g., Håkansson et al, 1994;Japsen et al, 2021), we found that quartz veins within the Nakkehoved Formation are not restricted to a single exposure but also occur in situ in another outcrop of the Nakkehoved Formation in Kronprins Christian Land (Figures 2a, Table S1 and Figure S1 in Supporting Information S1).…”

“…Japsen et al. (2021) found that the thickness of the Thyra Ø Formation at Kap Rigsdagen was less than 3 km based on VR and AFT data. The observed thermal maturity may hence simply be a result of burial without a thermal anomaly.…”

“… Geological maps of the study areas on the conjugate margins of eastern North Greenland (a) and western Svalbard (b) with thermal maturities published by Håkansson et al. (1994), Kleinspehn and Teyssier (1992), Paech and Estrada (2019), and Paech and Koch (2001) decreasing to the hinterland (maps redrawn and compiled after Dallmann, 2020, Japsen et al., 2021; Piepjohn et al., 2016). Sample locations are marked as well as locations of published thermochronological data by Schneider et al.…”

“…Opening and subsequent widening and deepening of the Fram Strait was related to the uplift of pre-Miocene erosion surfaces in Greenland and Svalbard (Bonow & Japsen, 2021;Dörr et al, 2013;Dörr, Lisker, Piepjohn, & Spiegel, 2019), and to the formation of a middle to late Miocene unconformity in the offshore sediments of the Greenland shelf, detected by seismic data (Døssing et al, 2016). Previous thermal history models of thermochronology data from Greenland and Svalbard also frequently involve middle or late Miocene cooling (Blythe & Kleinspehn, 1998;Dörr et al, 2013;Dörr, Lisker, Piepjohn, & Spiegel, 2019;Japsen et al, 2021Japsen et al, , 2023, but these cooling periods are poorly constrained and differ in terms of their timing. We included Miocene cooling as a constraint in our thermal history inversions.…”

“…(2019) (square), a zircon fission track age by Blythe and Kleinspehn (1998) (triangle), zircon (U‐Th)/He ages by Barnes and Schneider (2019) (diamond) and Apatite fission track ages by Blythe and Kleinspehn (1998) and Japsen et al. (2021) (circle). The time and location of volcanism are based on Døssing et al.…”