Tectonic control on sedimentation, erosion and redeposition of Upper Jurassic sandstones, Central Graben, North Sea - From Depositional Systems to Sedimentary Successions on the Norwegian Continental Margin - page 486

ripples and no bioturbation. Age equivalent sand-
stones of Franklin Field were equivocally inter-
preted as either turbidite sandstones or high
energy foreshore/shoreface deposits (Lasocki et al .,
1997). The Late Oxfordian/early Kimmeridgian
Freshney Sandstone Member in the Jacqui area
(Fraser et al ., 2002) is a further example of turbid-
ite sandstone units.
Previous studies have concluded that turbidite
deposits such as the Ribble Member are the depos-
its of turbidite lobes directly sourced from adja-
cent structural highs (Robinson, 1990). Other
studies have tried to show evidence that these
lobes were sourced during lowstands by fluvial
systems that delivered sediment through incised
valleys (e.g. Howell & Flint, 1996; Carruthers
et al ., 1996).
An alternative model previously proposed is
that hyperpycnal flows (Mulder & Syvitski, 1995;
Mulder et al ., 2003) brought sand-rich sediment
from high sediment-load rivers. Forster (2005)

used this model to explain the thick, sandstone-
dominated succession (Oxfordian-Volgian age)
of the Buzzard Field in the Outer Moray Firth
(Doré & Robbins, 2005). These deposits consist of
parallel laminated or massive sandstones similar
to the Ribble Sandstone Member T4 facies and
are interpreted to be sourced from an updip
braided river system.

TECTONO-SEDIMENTARY SETTINGS
A, B AND C

A schematic map (Fig. 8) indicates the global dis-
tribution of Oxfordian shoreface to basinal sand-
stones within the Central Graben. The extent of
the coastal plain is largely inferred since most of
these deposits were reworked by shoreface erosion
during subsequent transgression. The map is
adapted from that of Erratt (1999) and Fraser et al .
(2002), with local updates. The broad shoreface

Elgin
Figure 15

Ula

Shearwater

Franklin

Gyda
Figure 12

Puffin

2/4-14
Figure 11

Norwegian
Sector

Jacqui
Figure 22

2/4-20

1/6-6 & 7

Fulmar
Figure 10

UK Sector

N

Danish
Sector

50 km

Hinterland Up. Shoreface Shallow basin

Coastal plain Lw. Shoreface Deep basin

Fig. 8. Central Graben depositional setting during the Oxfordian. Facies belts are based on generalised models of Fraser et al .
(2002) and Erratt et al . (1999) with local adaptions. Top Pre-Zechstein faults (as shown in Fig. 1) are superimposed to indicate
the manner in which these faults are perceived to influence depositional trends. The figure is at the same scale as Fig. 1 with
which it is intended to be compared. The location of a correlation section shown in Fig. 5 is indicated by red well locations,
as are the location of several geological sections that are indicated on the map with their associated figure number.