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Increased accommodation in the northern area
may instead have been created by a higher post-rift
crustal cooling and subsidence of this particular
part of the basin.
The T-R 2 sequence corresponds with allostrati-
graphic unit 3 (Table 4) and is restricted to the
southern area (Fig. 14). The southward thickening
T-R 2 sequence was initiated by the transgressive
surface TS2. The overlying transgressive systems
tract TST2 displays a semi-regional flooding of the
underlying regressive systems tract RST1. MFS2
marks the initiation of the regressive systems tract
RST2 (Fig. 14). The northward amalgamation of
TS2 with the MFS2 is indicative of a wide trans-
gression at this stage. Proximal depositional envi-
ronments prevailed towards the north, partly
shallow-marine and partly emerged, whereas the
southern area was entirely drowned. In the north-
ern area, T-R 2 deposits were either not deposited or
thin and eroded during the fall in relative sea-level
that caused the establishment of the combined
SU1/TS3 surface that terminates the T-R 2 sequence.
The T-R 3 sequence corresponds with the
allostratigraphic unit 4 (Table 4). The basal uncon-
formity surface SU1/TS3 reflects a basin-wide fall in
relative sea-level and formation of low relief incised
valleys on top of the T-R 2 and T-R 1 sequences in
the southern and northern areas, respectively. The
total amount of subaerial erosion beneath the SU1/
TS3 is uncertain. An overall aggradational architec-
ture of the T-R 3 sequence implies that during the
rise in relative sea-level, a close balance existed
between rate of creation of accommodation space
and rate of sediment supply (A/S ratio ~ 1). Due to
this, the position of MSF3 is not immediately obvi-
ous and the regressive systems tract RST3 resembles
much of the TST3. The most proximal deposits of
the T-R 3 sequence in the southern area are topped
by the TS4 surface marking the succeeding trans-
gressive ravinement and flooding event. This
explains the observed mixing of terrestrial and
marine debris along TS4 (see above).
The T-R 4 sequence corresponds with the
allostratigraphic unit 5 (Table 4) and is restricted
to the southern area (Figs 7 and 14). The T-R 4
sequence is bounded below by TS4, which also
may have been present in the northern area prior
to the erosion that formed the incised valley along
the SU2/TS5 surface (Fig. 14). The separation of
TST4 and RST4 in the stratal architecture is not
obvious. However, the MFS4 is placed at the base
of the faint upward-coarsening regressive systems
tract RST4 (Fig. 7). The upper surface of the T-R 4
sequence (SU2/TS5) records up to 16 m deep inci-
sion south of locality S5, whereas northwards the
entire sequence has been removed (Figs 7 and 14).
The T-R 5 sequence is composed of the allostrati-
graphic units 6 and 7 (Table 4) and is underlain by
the unconformity surface SU2/TS5. This surface
reflects a basin-wide fall in relative sea-level and
formation of a new set of incised valleys. The
transgressive systems tract TST5 reflects drown-
ing and infilling of the incised valleys along the
FSf that represents a diachronous and abrupt
increase in accommodation space. A condensed
section with hardground sandstone defines the
maximum surface MFS5 and the shift from TST5
into progradational and aggradational RST5 in the
southern and northern areas, respectively (Fig. 14).
In the regressive systems tract RST5, shell-beds
record pauses or stagnation in sediment input.
Sequence T-R 5 was terminated by a new fall in
relative sea-level and formation of new incised
valleys along SU3/TS6. Approximately 40 m of
RST5 was locally eroded during this stage (Fig. 14).
The T-R 6 sequence corresponds with the
allostratigraphic unit 8 (Table 4). The basal uncon-
formity surface SU3/TS6 reflects a fall and rise in
relative sea-level and formation of another set of
incised valleys. The transgressive systems tract
TST6 reflects infilling and drowning of the incised
valleys along the marine FSg that represents a dia-
chronous and abrupt increase in accommodation
space and water depth. Across this flooding sur-
face, the Jameson Land Basin turned into an open-
marine environment defined by the Sortehat
Formation. MFS6, located within the Sortehat
Formation, is diachronous towards the north (Dam
& Surlyk, 1998; Koppelhus & Dam, 2003; Surlyk,
2003). The strata above FSg suggest regional back-
stepping of all facies belts and regional transgres-
sion towards the north, west and east of the Jameson
Land Basin. The unconformity between the
Sortehat Formation and the overlying Vardekløft
Group deposits marks the top of the T-R 6 sequence
and a major Middle Jurassic (Bajocian-Bathonian)
regression in East Greenland.
DISCUSSION
Sediment infill dynamics of the Neill
Klinter Group
The Neill Klinter Group in Jameson Land, East
Greenland, is an excellent field laboratory for the
multi-scale stratal complexity resulting from the
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