UNIVERSITY OF SOUTH ALABAMA GY 402: Sedimentary Petrology Lecture 6: Primary and Diagnostic Sedimentary Structures Instructor: Dr. Douglas W. Haywick
Today s Lecture 1. Models of traction structures 2. Sediment transport versus aggregation 3. Wave ripples 4. Erosional features 5. Surface features 6. Intrusive (dewatering & loading) structures 7. Really diagnostic structures (just a couple!)
Models of Traction Structures 1) Small current ripples 30 cm From Reineck, H.-E. and Singh, I.B. 1980. Depositional Sedimentary Environments. Springer-Verlag, Berlin. 549p.
Models of Traction Structures 50 cm From Reineck, H.-E. and Singh, I.B. 1980. Depositional Sedimentary Environments. Springer-Verlag, Berlin. 549p.
Models of Traction Structures From Reineck, H.-E. and Singh, I.B. 1980. Depositional Sedimentary Environments. Springer-Verlag, Berlin. 549p.
Models of Traction Structures 1) Small current ripples current 15 cm Harms, J.C., Southard, J.B., Spearing, D.R. and Walker, R.G., 1975. Depositional Environments as Interpreted from Primary Sedimentary Structures and Stratigraphic Sequences. SEPM Short Course 2.
Models of Traction Structures 1) Small current ripples (Linguoidal) 10 cm From Reineck, H.-E. and Singh, I.B. 1980. Depositional Sedimentary Environments. Springer-Verlag, Berlin. 549p.
Models of Traction Structures 1) Small current ripples (lunate) 30 cm From Reineck, H.-E. and Singh, I.B. 1980. Depositional Sedimentary Environments. Springer-Verlag, Berlin. 549p. 100 cm
Models of Traction Structures 2) Large current ripples 50 cm From Reineck, H.-E. and Singh, I.B. 1980. Depositional Sedimentary Environments. Springer-Verlag, Berlin. 549p. 100 cm From: Harms, J.C., Southard, J.B., Spearing, D.R. and Walker, R.G., 1975. Depositional Environments as Interpreted from Primary Sedimentary Structures and Stratigraphic Sequences. SEPM Short Course 2.
Large Current Ripple Aggregation/Erosion Computer animation of ripple migration Sorry: This image will not play in on line videos Source: USGS Coastal & Marine Geology Web page (http://walrus.wr.usgs.gov/seds/).
Models of Traction Structures Erosion removes bed form topography 75 cm 30 cm Trough-cross stratification From: Harms, J.C., Southard, J.B., Spearing, D.R. and Walker, R.G., 1975. Depositional Environments as Interpreted from Primary Sedimentary Structures and Stratigraphic Sequences. SEPM Short Course 2.
Migration versus aggregation current aggregation migration
Transport versus aggregation 30 cm From Reineck, H.-E. and Singh, I.B. 1980. Depositional Sedimentary Environments. Springer-Verlag, Berlin. 549p. Climbing Ripples
Transport versus aggregation
Transport versus aggregation
Transport versus aggregation Climb angle
Wave ripples Form through the action of orbicular flow
Wave ripples From Reineck, H.-E. and Singh, I.B. 1980. Depositional Sedimentary Environments. Springer-Verlag, Berlin. 549p.
Wave ripples Crossstratification records aggregation versus transport From Reineck, H.-E. and Singh, I.B. 1980. Depositional Sedimentary Environments. Springer-Verlag, Berlin. 549p.
Erosional structures Rip up clasts
Erosional structures Rip up clasts Scours
Erosional structures Rip up clasts Scours Channels
Erosional structures Both from Reineck, H.-E. and Singh, I.B. 1980. Depositional Sedimentary Environments. Springer-Verlag, Berlin. 549p. Rip up clasts Scours Channels Flute marks Surface view
Erosional structures Rip up clasts Scours Channels Flute marks Under bed view From Reineck, H.-E. and Singh, I.B. 1980. Depositional Sedimentary Environments. Springer-Verlag, Berlin. 549p.
Erosional structures Rip up clasts Scours Channels Flute marks Tool marks From Lucchi, F.R.,1995. Sedimentographica. Second Edition. Columbia University Press. 255p.
Surface features Rain drop imprints Mudcracks Modern Ancient (Triassic) 75 cm http://www.bedford.k12.ny.us/flhs/science/geoscience/images/mudcrackssample.jpg
Surface features Rain drop imprints Mudcracks Beastie trails Modern Ancient (Silurian) 40 cm http://www.fossilmall.com/stonerelic/trace%20fossils/dd39/dd39c.jpg
Surface features Rain drop imprints Mudcracks Beastie trails Parting lineations Ancient (Permian) Modern 75 cm http://ic.ucsc.edu/~casey/eart150/lectures/foliations&lineations/partinglinparrsbourghns.jpg
Intrusive structures Loads From Lucchi, F.R.,1995. Sedimentographica. Second Edition. Columbia University Press. 255p.
Intrusive structures Loads Ball and pillows From Reineck, H.-E. and Singh, I.B. 1980. Depositional Sedimentary Environments. Springer-Verlag, Berlin. 549p.
Intrusive structures Loads Ball and pillows Sand dykes (dewatering)
Intrusive structures Loads Ball and pillows Sand dykes Mud volcanoes 20 cm 3 m Both from Reineck, H.-E. and Singh, I.B. 1980. Depositional Sedimentary Environments. Springer-Verlag, Berlin. 549p.
Intrusive structures Loads Ball and pillows Sand dykes Mud volcanoes Monroes 20 cm From Reineck, H.-E. and Singh, I.B. 1980. Depositional Sedimentary Environments. Springer-Verlag, Berlin. 549p.
Really diagnostic sedimentary structures 1) Beach environments Low angle crossstratification Both from: Harms, J.C., Southard, J.B., Spearing, D.R. and Walker, R.G., 1975. Depositional Environments as Interpreted from Primary Sedimentary Structures and Stratigraphic Sequences. SEPM Short Course 2.
Really diagnostic sedimentary structures 2) Muddy tidal environments flaser bedding wavy bedding lenticular bedding All from Reineck, H.-E. and Singh, I.B. 1980. Depositional Sedimentary Environments. Springer-Verlag, Berlin. 549p.
Really diagnostic sedimentary structures 3) Sandy tidal environments Herringbone crossstratification From Reineck, H.-E. and Singh, I.B. 1980. Depositional Sedimentary Environments. Springer-Verlag, Berlin. 549p.
Really diagnostic sedimentary structures 4) Deep marine environments (density currents) Turbidites From Lucchi, F.R.,1995. Sedimentographica. Second Edition. Columbia University Press. 255p.
Really diagnostic sedimentary structures 4) Deep marine environments (density currents) Graded bedding HCS (hummocky cross-stratification) From: Harms, J.C., Southard, J.B., Spearing, D.R. and Walker, R.G., 1975. Depositional Environments as Interpreted from Primary Sedimentary Structures and Stratigraphic Sequences. SEPM Short Course 2.
GY 402: Sedimentary Petrology Lecture 6: Sedimentary Structures Instructor: Dr. Doug Haywick dhaywick@southalabama.edu This is a free open access lecture, but not for commercial purposes. For personal use only.