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sea-level, are more in favour of a deeper estuary
depositional setting than in the southern incised
valley system. Both incised valley fill successions
are draped on top by the same flooding surface,
FSf (Figs 10A and B, 11A and B, 13A and B) and
represents the stage when the sea also flooded
inter-valley areas at all localities (Fig. 7).
The over 50 km-wide poorly exposed area
between localities S6 and N1 may conceal another
valley-fill system since the widths of the two
observed incised valley systems are in the order of
some tens of kilometres. Alternatively, an inter-
valley land area or a shallow marine embayment
may be present within the unexposed area.
posed of 10 to 15 m thick, heterolithic upward-
coarsening units capped by up to 1.5 m thick and
several hundred metres-wide well-cemented
fossiliferous sandstone beds (Fig. 11A and B).
These fossiliferous beds contain abundant oys-
ter shells with a diameter of up to 10 to 15 cm
and shell walls up to 1 cm thick, belemnites,
shell remains and local concentrations of abun-
dant small shells (<2 cm in diameter). The degree
of bioturbation and species diversity is generally
high. Locally, upward-coarsening units may also
be capped by few metres-thick bedsets com-
posed of up to 1 m thick cross-stratified sand-
stone beds of low-angle delta-lobe facies
association (FA7a; Table 2).
At locality N1, the well-cemented beds are
restricted to the lower half of allostratigraphic
unit 7, whereas the upper half of the unit is
chiefly wave-dominated and bioturbated hetero-
lithic sandstones of low-angle delta lobe facies
association (FA7a) with floating belemnites and
high degree and diversity bioturbation com-
pared to other allostartigraphic units. At locality
N2, no sandstone beds are observed in allostrati-
graphic unit 7 which is here composed of poorly
consolidated silty brackish-marine embayment
facies associations (FA6a and 6b; Table 2). At
localities N3 and 4, a single bed of fossiliferous
hardground facies association (FA6b) is observed
within stacked metre-thick, upward-coarsening
and heavily bioturbated muddy heterolithic
beds of low-angle delta-lobe facies association
(FA7a) (Fig. 13A; Table 2). Biostratigraphy sam-
ples collected from the northern area include
brackish palynomorphs at locality N2 (Ahokas
et al
., 2014).
Allostratigraphic unit 7
Description: Retrogradational to progradational
architectural elements
At all localities, the sandstone-dominated to sandy
mudstone-dominated allostratigraphic unit 7 is 12
to 75 m thick and overlies the flooding surface FSf
(Fig. 7). Allostratigraphic unit 7 is dominated by
sandy heterolithic wave-dominated open marine
facies associations (FA7a and 7b) but includes also
brackish-marine embayment facies associations
(FA6a and 6b) (Figs 11A and B, 12A, B and E and
13A; Table 2). At all the localities except for N1,
allostratigraphic unit 7 is terminated on top by the
SU3/TS6 unconformity (Fig. 7).
At locality S3, up to 14 m of basal allostratigraphic
unit 7 is defined by southward-thickening, upward-
coarsening, mudstone-dominated to sandstone-dom-
inated inclined heterolithic strata facies association
(FA2b) and heterolithic tidal channel infill facies
associations (FA3a, 3b and 3c) with dominantly
marine palynomorphs (Figs 7, 10A and B; Table 2).
The base of these cross-stratified sandstone facies
associations of allostratigraphic unit 7 are either an
up to 2m thick, greenish upward-fining bed with
gravelly base (Fig. 5F), or well sorted light coloured
structureless sandstone bed (Fig. 10A). These facies
associations also record slight upward increase in
amount of body fossils and intensity of trace fossils
(Fig. 5A and 10B). The upper boundary of the sand-
stone-dominated facies associations of allostrati-
graphic unit 7 is an erosive surface locally covered by
a thin conglomerate bed composed of quartz and
quartzite pebbles and marine body fossil fragments
(Fig. 5E). Across this erosive surface, the diversity and
amount of trace fossils increase abruptly in the hetero-
lithic low-angle delta-lobe facies association (FA7a).
At localities S3 to 6, the open marine facies
associations of allostratigraphic unit 7 are com-
Interpretation: Allostratigraphic unit 7
Based on the facies and high degree of marine micro
fossils, trace fossils and body fossils, the dominant
sandy heterolithic facies associations of allostrati-
graphic unit 7 overlying the FSf, are interpreted as
wave-dominated delta-lobe (WDDL) architectural
element (Figs 7, 11A and B, 12B, 13A; Table 3).
At locality S3, the FSf is interpreted as a diachro-
nous drowning and marine transgressive ravine-
ment surface (MTRS) along the base of the
retrogradational deltaic deposits of the tide-domi-
nated sub-tidal sandy shoal (TDSS) arhitectural ele-
ment (Figs 5A, 10A and B; Table 3). Based on the
facies architecture allostratigraphic unit 7 is inter-
preted to have formed by stacking of distal offshore
delta lobes. These stacked prodelta and offshore
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