This document discusses sedimentology and ichnofabrics. It includes definitions of ichnofabrics and observations of trace fossils and their relationship to depositional environments like shoreface, tidal channels, and inner and outer shelf. Graphs show permeability, borehole images and thin sections. The document examines bioturbation, ichnofauna diversity, burrow organization, tiering and lithology. It discusses sedimentary structures like cross-beds and heterolithics. Fabric analysis is also covered, looking at the resolution of bioturbation fabrics, a fabric index determined via flash cards, and using the fabric index for quantitative description of lithofacies.

1. Sedimentology 2/1
Image log & dipmeter
analysis course
Ichnofabrics – recognition
& interpretation

2. Sedimentology 2/2
“Those aspects of the sediment's texture and internal
structure that arise from bioturbation and bio-erosion at all
scales" (Ekdale & Bromley 1983).
“A record of the primary sedimentary conditions, original
animal community, and subsequent history of one or more
phases of biogenic activity” (Taylor & Goldring 1993).
Definitions

3. Sedimentology 2/3
_ 3.41
_ 1.64
_ 2.35
_ 0.21
_ 0.75
_ 2.81
_ 1.81
Log K
Permeability map
Thin section
Core
Microporous nodular limestones

4. Sedimentology 2/4
•Degree of bioturbation
•Ichnofauna
•Diversity
•Burrow organisation
•Tiering
•Lithology
•Sedimentary structures
Observations

5. Sedimentology 2/5

6. Sedimentology 2/6
Trace fossils Environment
Shoreface Shelf
Tidal Foreshore Upper Middle Lower Inner Outer
Arenicolites x x x x x
Asterosoma x x
Bergaueria x x x x x
Chondrites x x
Conichnus x x x x x
Diplocraterion x x x
Escape structures x x x x x x
Gyrolithes x x
Lockeia x x
Macaronichnus x x x x
Monocraterion x x
Muensteria x x x
Ophiomorpha x x x x
Palaeophycus x x x x x
Phycosiphon x x x
Planolites x x x x x x
Rhizocorallium x x
Roots
Rosselia x x x
Scolicia x x x
Siphonites x x x
Skolithos x x x x x x x
Taenidium
Teichichnus x x x
Terebellina x x x
Thalassinoides x x x x x x
Trichichnus x x x

7. Sedimentology 2/7
Cross-beds, clay-draped
foresets, bidirectional,
thick bottomsets, flaser
bedded.
Variable bioturbation,
moderate diversity.
Planolites
Macaronichnus
Ophiomorpha
Thalassinoides
Palaeophycus
Tidal channel

8. Sedimentology 2/8
Cross-bedded to
parallel-laminated
sands.
Variable bioturbation,
moderate diversity.
Ophiomorpha
Scolicia
Planolites
Macaronichnus
Upper shoreface

9. Sedimentology 2/9
Fair weather deposits;
sandy heterolithics.
Storm deposits, HCS-SCS
sands.
Intensely bioturbated, high
diversity.
Phycosiphon, Rhizocorallium
Teichichnus, Palaeophycus
Sparsely bioturbated, low
diversity.
Ophiomorpha
Lower shoreface

10. Sedimentology 2/10
Muddy heterolithics.
Intensely bioturbated,
high diversity.
Phycosiphon
Teichichnus
Planolites
Chondrites
Rhizocorallium
Inner shelf

11. Sedimentology 2/11
Bioturbated mudstone.
Laminated mudstone.
Sparsely bioturbated, low
diversity.
Phycosiphon
Thalassinoides
Intensely bioturbated,
moderate diversity.
Phycosiphon
Chondrites
Planolites
Outer shelf

12. Sedimentology 2/12
Resolution of bioturbation fabrics

13. Sedimentology 2/13
Fabric index - determined via flash cards
Mottling and loss of fabric in this example is due to
bioturbation - hence we have a bioturbation index
Fabric index

14. Sedimentology 2/14
Fabric Analysis adds an extra
dimension to lithofacies description if
it can include a quantitative descriptor.
E.g. Well laminated versus poorly
laminated, and stages in-between.
Fabric index from dipmeter curve activity