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should display an increasingly pelagic character.
Pelagic or mixed hemipelagic-pelagic mudstones
thus commonly mark a more significant strati-
graphic event than do the hemipelagic lobe storey
caps and probably reflect higher order, longer dis-
tance avulsions or longer-term cessation of sandy
sediment supply. As such, the enclosing mudstones
have the potential to be used as indicators of poten-
tial avulsion distance and thereby hierarchal order.
et al
., 2001, 2005; Smith & Møller, 2003; Møller
et al
., 2004; Sømme
et al
., 2009) on the Ormen Lange
fan systems. The most significant contrasts with pre-
vious studies are the subdivision of the Upper
Maastrichtian to Danian section into two entirely
separate fan systems, both of which developed
across nearly the full length of the Late Cretaceous
and Danian Møre ramp margin. Furthermore, the
recognition of different depositional styles or fan
types, and component depositional elements from
the early through the late progradational stage to the
final backstepping stage, has also not been recog-
nised in previous studies. The repeated develop-
ment of fan systems with a common evolutionary
history for the Springar and Egga fans, linked to an
integrated basinal structuring and sediment supply
history, also appears to constitute a common theme
in other tectonically active basins.
Vertical changes from an overall lobe-dominated
outer to middle fan to a channelised inner fan
environment is to be expected for any outbuilding
submarine fan system. Such a simple fan progra-
dation story may apply for the bulk of the Egga or
Danian fan system. However, the change to isolated
channels and channel-mouth lobes with inter-
channel areas dominated by scoured, unstable
basin-floor during the final stages of fan system
development (where soft-sediment deformation
cannot be linked to levee or overbank failure),
calls for allogenic controls, herein attributed to
slope structuring and tilting. Slope tilting, causing
changes in depositional style is also suggested
by: 1) the relatively sharp transitions from outer
to inner (Springar) and middle to inner (Egga)
fan facies tracts; 2) the lack of extensive lobe
complexes fronting the late-stage, fan channel
complexes; 3) the facies characteristics of the late-
stage MTD-influenced fan (e.g. the co-occurrence
of frontal splays and intervening mass transport
deposits); and 4) the change in background facies
that accompanied the transition into the MTD-
influenced fan stage.
The impact that the linked hinterland-basin
structuring has on the development of basin-mar-
ginal deltaic delivery and, consequently on the
fronting slope to basin-floor turbidite systems
has been noted in nearly all types of tectonically
active settings. The analogue Permian Laingsburg
turbidite complex was also deposited on a ter-
raced to mildly irregular slope subject to repeated
deformation events (Grecula
et al
., 2003b),
although lying within a compressive, foreland
setting. Interestingly, the Laingsburg turbidite
Intervening mudstones
The lack of, or thin, character of the interbedded
mudstones is a conspicuous feature of the Springar
(in upslope mini-basins) and Egga sandstone
successions (see also Smith & Møller, 2003).
Furthermore, there appears to be a characteristic
partitioning of the various mudstone types across
the fan surface (Fig. 7C). The character and distri-
bution of the interbedded mudstones in the two
sandstone units are here attributed to the inferred
slope setting for the development of both the
Springar and Egga fans. This setting promoted: 1)
bypass of, and downslope deposition from the
turbulent portions of the flows; 2) the continuous
sweeping of the fan area by slope-parallel cur-
rents, which would have retarded and possibly at
times prevented suspension fall-out over the inner
to central parts of the fan area; and 3) some erosion
by subsequent flows, evident by rip-up clasts and
dispersed fragmented claystone chips. Mudstone
fragments are normally more common in the basal
beds of a lobe storey, suggesting that sandy depo-
sitional events within a lobe storey potentially
occurred too frequently for suspension fall-out or
mudstone partings to form, especially during the
later stages of lobe storey formation. The broader
implication of this is that mudstone deposition
across the inner to central fan area mainly occurred
during inter-flood intervals, forming candidate
extensive drapes that envelope the more locally
developed sandy reservoir elements (Figs 5 and 14).
The thin character of the enclosing mudstones is
attributed to the overall sediment-starved conditions
for the eastern Møre Basin, especially during the
Danian.
DISCUSSION
The sedimentological model and depositional his-
tory proposed above share some similarities and dif-
ferences with those of earlier studies (e.g. Gjelberg
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