Channel development in the chalk of the Tor Formation, North Sea: evidence of bottom current activity - From Depositional Systems to Sedimentary Successions on the Norwegian Continental Margin - page 573

WNW ESE

Exploration well
2/4-12

Exploration well
2/8-15

% %

clast size (mm) clast size (mm)

Top Tor Fm

Upper channel
unit

Upper channel
unit

GR Ø D

Lower channel
unit

Lower channel
unit

Base channel
reworked zone

Base channel
reworked zone

GR Ø D

Metres TVDSS

LEGEND

Argillaceous
bioturbated chalk

Interpreted limits
of the channel structure
GR = Gamma ray (0−30 API)
Ø = Neutron Porosity (-0.15−0.45 %)
D = Density (1.95−2.95 g/cm 3 )

Homogeneous chalk

Packstone and
grainstone

Laminated chalk

Bioturbated
homogeneous chalk

Upper unit low
porosity interval

Deformed chalk

Low porosity

Pebble floatstone

High porosity

Fig. 14. Well correlation panel parallel to the channel axis, flattened at the top of Tor Formation. The position of the well
correlation is indicated in Fig. 4. Depths are given in True Vertical Depth Sub Sea (TVDSS).

feature may be related to both turbidity and
bottom currents and that a complex interaction of
inversion tectonics, gravity-driven processes and
superimposed bottom currents controlled chalk
reworking and re-deposition.

The channel of the current study is interpreted
to have been developed by contour-parallel bottom
currents. It is broadly oriented in a contour parallel
rather than a downslope direction, making gravity
flow processes a less likely generative mechanism.