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lateral evolution is documented by the lower energy
shoal deposits on top of larger basal bar forms.
As the rise in relative sea-level continued, the
upper part of the valley widened, tidal dominance
decreased and wave-influenced deposits succes-
sively became more abundant. The change from
tidal energy system to wave dominance is well
marked across the regional flooding surface (FSg)
previously interpreted as a transgressive erosional
ravinement surface (Surlyk, 1990a, b; Hansen &
Surlyk, 1994; Koppelhus & Hansen, 2003) (Fig. 7).
At this stage, the incised valley of the allostrati-
graphic unit 8 was filled up.
The heterolithic to muddy deposits overlying
the flooding surface (FSg) record continued north-
west and north-east retrogradation. The biostratig-
raphy sample collected approximately 15 m above
the FSg (locality N2) is dominated by brackish
marine dinoflagellate cysts (
Nannoceratopsis gra-
cilis/senex
), brackish or freshwater planktonic alga
(
Botryococcus
spp.) and relatively abundant pollen
(
Perinopollenites elatoides, Callialasporites
spp.
and
Cerebropollenites
spp.). This indicates mix-
ing of fresh waters and marine waters during the
early stages of marine transgression and is in
accordance with the interpretation of Koppelhus
& Hansen (2003). Petrified wood fragments sam-
pled during this study, approximately 20 m above
the FSg, indicate proximity to land areas with
suitable living conditions for rather large trees.
The MFS6 surface has not been identified in the
measured sections but is inferred to be located
within the middle to upper part of the Sortehat
Formation. The occurrence of the Vardekløft
Group (e.g. Surlyk, 2003) shoreface sandstones
above the Sortehat Formation (SORT architectural
element; Table 3) defines the next major retrograda-
tional to progradational depositional cycle.
Early Jurassic (Pliensbachian-Aalenian) succession
from sea-level lowstand to highstand, confirming
earlier reports (Surlyk, 2003 and references therein).
This first order transgressive systems tract (cf. Haq
et al
., 1987; Hallam, 1988) includes six higher fre-
quency transgressive-regressive sequences (
sensu
Embry 1989, 1993, 1995) listed in Table 4. These
T-R sequences in the Neill Klinter Group are each
composed of one or more of the allostratigraphic
units (Table 4) and are summarised in Figs 7 and 14.
T-R sequences
T-R 1 is composed of the allostratigraphic units 1
and 2 (Table 4) and is bounded below by the trans-
gressive marine ravinement surface (TS1) on top
of the continental lowstand deposits of the Kap
Stewart Group (Figs 7 and 14). The transgressive
systems tract TST1 corresponds to the up to 25 m
thick allostratigraphic unit 1 and reflects dia-
chronous northwards marine flooding of the
Jameson Land Basin during the Early Pliensbachian.
The flooding surface FSa marks the drowning of
initial transgressive deposits in the southern area.
The FSa has not been identified in the northern
area, but may here coincide with the MFS1.
MFS1 separates the allostratigraphic units 1
and 2 and hence also TST1 from the regressive
systems tract RST1. The up to 127 m thick RST1
records at least four high-frequency cycles of fall
and rise in relative sea-level, bounded by flooding
surfaces FSb to FSe (Figs 7 and 14). Based on
facies, these cycles took place during a period of
overall upward shallowing, likely caused by an
increase in rate of sedimentation relative to rate in
creation of accommodation space. Palynomorphs
indicate an upward increase of terrestrial/brack-
ish dominance, thus supporting the interpretation
of a basinwide regression (Koppelhus & Dam,
2003; this study).
Strata of the T-R1 sequence show a total thick-
ening towards the north by 60 m over a distance of
50 km (Figs 7 and 14). Surlyk (2003) interpreted
this as caused by increased subsidence on the
northern side of deep-seated faults between the
southern and northern areas. In this study the
analysis of onshore seismic data from Grønlands
Geologiske Undersøgelse and Arctic Richfield
Exploration Company (unpublished seismic data
1986 to 1989, available on loan to academic insti-
tutions from the Geological Survey of Denmark
http://www.geus.dk/geuspage-uk.htm
) do not
support the hypothesis of deep-seated faults.
OVERALL TRENDS: SEQUENCE
STRATIGRAPHY
The sequence stratigraphical analysis of the Neill
Klinter Group is based on key stratal surfaces and
the spatial occurrence of architectural elements
within the above described allostratigraphic units 1
to 8. In this context, palynostratigraphic data, both
published (Koppelhus & Dam, 2003; Koppelhus &
Hansen, 2003; Surlyk, 2003) and collected for this
study have been of significant importance.
The two stratigraphic compartments of the
Neill Klinter Group define an overall transgressive
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