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 560

(A)

2-4-12

MD
(m)

Gamma Ray
API

-0.15 Por.

Den. 2.95

0.45

Core
facies

1.95

0 30

(B)

MD
(m)

Core 4

Top Tor Fm

J

Top Channel

I

3330

H

G

3335

F

3340

E

3343.7

Core 5

D 3365

C

B

A

3369.6

LEGEND

Core facies Sedimentary structures Biogenic structures

Flat lamination

Argillaceous bioturbated chalk Thalassinoides

High angle lamination

Chondrites
Zoophycos
Planolites

Laminated chalk

Wavy lamination

Bioturbated homogeneous chalk

Convoluted bedding

Crenulated bedding

Deformed chalk

Well log intervals

Pebbles

Upper unit low
porosity interval

Pebble floatstone

Grains

Flint nodules and silicified beds

Homogeneous chalk

Low porosity

Water escape structure

Packstone and
grainstone

High porosity

Shell fragments

Foraminifer

Fig. 8. Composite log of well 2/4-12 (Fig. 6), including (A) wireline logs, core facies and (B) related sedimentological logs.
Note the cyclic changes in porosity in the upper unit. MD = measured depth; Den = density log in g cm -3 ; Por = neutron
porosity. API = American Petroleum Institute units. Capital letters at the margin of sedimentological log refer to facies
photographs in Fig. 13. Well location in Figs 1 and 4.