The Cretaceous–Paleocene sedimentary succession of
the Nuussuaq Basin onshore West Greenland is best
known from eastern Disko and Nuussuaq, with minor,
and less well-known, outcrops in the northern part of
the region on Upernivik Ø, Qeqertarsuaq and Svartenhuk
Halvø (Fig. 10). Seismic and other geophysical data indi-
cate that the Mesozoic succession is at least 6 km and
possibly up to 10 km thick in the western part of the
basin (Christiansen et al. 1995; Chalmers et al. 1999;
Marcussen et al. 2002). The eastern part appears to have
much shallower depths to basement (Chalmers et al.
1999), and this part of the basin could represent ther-
mal subsidence following the initial rifting episode
(Chalmers et al. 1999).
The outcrops record a complex history of rifting, sub-
sidence and uplift commencing with an earliest Cretaceous
(or earlier) rift episode followed by a phase of thermal
subsidence during the Cenomanian – Early Campanian
(Fig. 11). Rifting resumed in the Early Campanian and
increased in the Maastrichtian – Early Paleocene (Dam
& Sønderholm 1998; Dam et al. 2000; Dam 2002),
culminating during the Early Paleocene. The first phase
of these later rift episodes was characterised by large-
scale normal faulting, whereas the later episodes were
associated with continued extension and regional uplift
(Dam & Sønderholm 1998; Dam et al. 1998a, 2000;
Chalmers et al. 1999). The late phases were accompa-
nied by widespread igneous activity and extrusion of a
thick succession of flood basalts (Fig. 12; A.K. Pedersen
et al. 2006a, and references therein).
The exposed part of the succession in the Nuussuaq
Basin can be divided into eight tectonostratigraphic
sequences (TSS; Fig. 11); the early rift episode includes
two sequences and the late episode six sequences. These
sequences are mainly related to tectonic events marking
discrete basin-fill phases (Dam & Nøhr-Hansen 2001).
TSS 1. The oldest sediments exposed in the Disko –
Nuussuaq Basin represent a syn-rift episode of ?Aptian–
Albian age represented by the Kome and Slibestensfjeldet
Formations (Fig. 11). This rift episode is dominated by
N–S extensional faults which, however, were also reac-
tivated during later stages (L.M. Larsen & Pedersen
1990; Chalmers et al. 1999). The N–S trend is expressed
particularly by the Disko Gneiss Ridge and this trend
can be followed on western Nuussuaq in the Kuugan -
nguaq–Qunnilik Fault (Figs 10, 12). The eastern bound-
ary fault system has an overall NNW–SSE trend but is
segmented with individual segments trending N–S or
NW–SE (Fig. 10; Rosenkrantz & Pulvertaft 1969;
Chalmers et al. 1999). The Kome Formation reflects an
environment dominated by fluvial plains and local fan
deltas amid basement highs. The Kome For mation is
overlain locally by lacustrine deposits of the
Slibestensfjeldet Formation.
TSS 2. Following the early rifting episode there was a long
period of thermal subsidence that spanned the late
Albian/Cenomanian – Turonian – earliest Campanian.
It was initiated by a major flooding surface represented
by offshore and deep marine deposits of the Itilli
Formation to the north and west and by fluvio-deltaic
and shallow marine deposits of the Atane and Upernivik
Næs Formations to the east and south. The delta fanned
out to the west and north-west from a point east of Disko
(Figs 11, 12A; G.K. Pedersen & Pulvertaft 1992). On
Nuussuaq, the transition from shallow marine and fluvio-
deltaic deposition in the eastern part of the basin into
deep marine deposition farther west was controlled by
the N–S-trending Kuugannguaq–Qunnilik Fault that
crosses Disko and Nuussuaq (Figs 10, 11, 12A). On
Svartenhuk Halvø contemporaneous deep-water depo-
sition in a slope setting is recorded by a thick distal tur-
bidite succession assigned to the Itilli Formation (Dam
1997). This unit includes marine anoxic shales of pre-
sumed Cenomanian–Turonian age, that are possibly the
source for the marine Itilli oil type (Dam et al. 1998b;
Bojesen-Koefoed et al. 1999).
TSS 3. In earliest Campanian time a new tectonic episode
was initiated that lasted from the Early Campanian to
the Paleocene (Dam et al. 2000). The early phase of this
rifting episode (TSS 3) is represented by the Aaffarsuaq
Member of the Itilli Formation and lasted into the
Maastrichtian. This phase is characterised by normal
faulting, subsidence and syn-rift sedimentation. It resulted
in the development of an angular unconformity, and
deltaic deposition gave way to catastrophic deposition
in a footwall fan setting along N–S-trending normal
faults. In the eastern part of the region, uplift resulted
in significant erosion of previously deposited Atane
Formation deposits, and it is therefore expected that tur-
bidite sandstone bodies of regional extent are present in
the deep-water facies in the offshore basins to the west.