Ch 4: Sedimentary Structures
TYPES OF BEDDING
bounding surfaces
discontinuous bedding
planar bedding
bedding
graded-bedding
normal graded bedding(fining up)
reverse graded bedding(fining down)
cross-beds
Ripples
ripples
cross-beddingripple video
EOLIAN (WIND) DEPOSITION
Wind
Former position Future position
DepositionErosion
A dune moves forward slowly as sand erodes and is deposited.
eolian cross-bed formation
cross-beds
eolian cross-bedding
eolian
IRREGULAR STRATIGRAPHY
FLAME STRUCTURES
http://www.dept.edu.waseda.ac.jp/earth/top/cover_ph/2004/flame.jpg
BALL AND PILLOW STRUCTURES
DISH AND PILLAR STRUCTURES
http://course1.winona.edu/csumma/images/sedstrx2/dishce.jpg
SOFT SEDIMENT DEFORMATION
http://www.tulane.edu/~eens/geol/fieldtrip2002/Soft_Sediment_Deformation_in_Mono_Lake_beds.jpg
SOFT SEDIMENT DEFORMATION
EROSIONAL STRUCTURES
Erosional Structures
GROOVE CASTS
http://commons.wikimedia.org/wiki/File:Groove_casts.JPG
FLUTE CASTS (CRETACEOUS)
LOAD CASTS
http://course1.winona.edu/csumma/images/sedstrx2/load.jpg
BIOGENIC STRUCTURES
Bioturbation structures
stromatolites
44
MISC STRUCTURES
mud cracks
PARTING LINEATION
http://www4.uwm.edu/course/geosci697/structures/partinglineationpage.html
PALEOCURRENTS
PALEOCURRENTSN (0)
S (180)
W (90)E (270)
N (0)
S (180)
W (90)E (270)
Total Data : 43
paleocurrent data e.g.
STRIKE/DIP
similar to Fig. 15.7
imbricated clasts
Unimodal
Unimodal
Bimodal
stratigraphic section
depositional environment
depositional environments
DepositionalenvironmentsDepositional Environments
3. depositional environments