1. Graphic Logs of
Sedimentary Rocks
I.G.Kenyon

2. Graphic Logs are a method used to record
details of sedimentary successions to scale
The vertical scale is used to record bed thickness
to scale, typically the scale will be between 1:10
(1 cm to 10cm) and 1:100 (1 cm to 1 metre)
The horizontal scale uses particle sizes of the Wentworth
Scale, on the left hand side is Clay, then moving to the right
is Silt, Sand, Granules, Pebbles, Cobbles and finally Boulders
A variety of symbols are used to indicate the presence
of sedimentary structures including graded bedding,
cross bedding, laminations, desiccation cracks,
ripple marks, flute casts and erosion surfaces

4. Symbols Used on Graphic Logs

5. Typical Glacial Sequence

6. Typical Fluvial (Meandering River Channel) Sequence

7. Desert Sequence

8. Deltaic Sequence – Coal Measures Cyclothem

9. Turbidity Current Sequence
(Bouma Sequence-5 Units)

10. Exam questions using graphic logs of sedimentary sequences

17. The End