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Snapshots

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  1. Gravel

    Snapshot Title: Gravel
    Taken by: Collin Burke

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    The gravel pictured here suggests that the river was flowing over this area at a fast rate.



  2. Stoss-erosional dunes

    Snapshot Title: Stoss-erosional dunes
    Taken by: Collin Burke

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    This feature is a textbook example of stoss-erosional dunes. This suggests a change in flow direction.



  3. Red to white

    Snapshot Title: Red to white
    Taken by: Collin Burke

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    The red mudstone suggests a distal overbank deposit, while the white sandstone indicates a proximal overbank deposit. This contact suggests that the channel migrated laterally.



  4. Soil Development-->Sediment Deposition

    Snapshot Title: Soil Development-->Sediment Deposition
    Taken by: Graham Edwards

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Same texture but change from massive red to massive white. Indicates an increase in sedimentation rate.



  5. z20

    Snapshot Title: z20
    Taken by: Andrew Murguia

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Proximal overbank - entire foreground



  6. HLams

    Snapshot Title: HLams
    Taken by: Rachel Barnes

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Shows continuous shallow fast flow as sediment deposits - suggesting a gravelly braided river



  7. Migrating stoss-erosional dunes

    Snapshot Title: Migrating stoss-erosional dunes
    Taken by: Kevin McDonough

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Migrating stoss-erosional dunes cut by erosion boundaries and potential reactivation surface. Potential scour and refill where roughly 60 degree lines coming down and to the right are offset by a wavy...



  8. Fining up sequence

    Snapshot Title: Fining up sequence
    Taken by: Madison Smith

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Erosion of channel into mud. Beginning with fastest flow, depositing gravel, transitioning into muds as channel slows and fills in.



  9. 3D Dunes

    Snapshot Title: 3D Dunes
    Taken by: Rachel Barnes

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Tangential



  10. Trough Cross strata

    Snapshot Title: Trough Cross strata
    Taken by: Madison Smith

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Cross strata with planar contact indicate trough set with flow likely into or out of outcrop



  11. z12

    Snapshot Title: z12
    Taken by: Andrew Murguia

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Trough cross-stratification



  12. H-lams

    Snapshot Title: H-lams
    Taken by: Sian Riebe

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    planar structures parallel and constant suggesting evidence of H-lams in sandstone. Formed in shallow flow?

    - Upper layer shows some evidence of stoss erosional dunes suggesting left to right flow ...



  13. Erosional Relief

    Snapshot Title: Erosional Relief
    Taken by: Madison Smith

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Shift from fine grain to coarser grain represents erosion of new channel into fine grained deposit.



  14. z9

    Snapshot Title: z9
    Taken by: Andrew Murguia

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Irregular surface?

    Or evidence for soft sediment deformation?



  15. Fining Up Sequence

    Snapshot Title: Fining Up Sequence
    Taken by: Kevin McDonough

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Goes from gravel to sand. Probably a change in the amount of discharge to less discharge and flow where sand deposition occurs.



  16. Band of Gravel

    Snapshot Title: Band of Gravel
    Taken by: Stephanie Lynn

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Image of a band of gravel representing the bottom of the channel.



  17. z8

    Snapshot Title: z8
    Taken by: Andrew Murguia

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    fine-coarse-fine-coarse layering; coarse grain directly on top of fine grain is suggestive of an erosional event



  18. Big Dog #2

    Snapshot Title: Big Dog #2
    Taken by: Joe Russo

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    JUST A BIG DOG sNAP



  19. Planar Tabular

    Snapshot Title: Planar Tabular
    Taken by: Stephanie Lynn

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    In the bottom of the image evidence for trough cross strata (3d dunes) and a fining up sequence. There is an erosional bounding surface mid frame and above coarser grained material and planar tabular...



  20. Dinosaur Head

    Snapshot Title: Dinosaur Head
    Taken by: Kevin McDonough

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    See title



  21. z7

    Snapshot Title: z7
    Taken by: Andrew Murguia

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Further evidence of trough cross stratification - an area of deeper flow



  22. Stoss-erosional migrating dune

    Snapshot Title: Stoss-erosional migrating dune
    Taken by: Kevin McDonough

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Stoss-erosional migrating dune over h-lams. Potential reactivation surface shown by changing angle of tangential cross-strata. Erosion boundary between regime change.



  23. z6

    Snapshot Title: z6
    Taken by: Andrew Murguia

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Three layers:

    Horizontal lamination going to trough cross stratification, returning to horizontal lamination

    Cross trough stratification shows lee sides of migrating dunes, but there is no evide...



  24. Trough cross strata

    Snapshot Title: Trough cross strata
    Taken by: Stephanie Lynn

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Evidence for 3d dune formation in the deepest and/or fastest part of flow.



  25. tangential cross-strata over hlams

    Snapshot Title: tangential cross-strata over hlams
    Taken by: Kevin McDonough

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    This shows some tangential cross strata overlying horizontal laminations. Suggests a change in flow dynamics



  26. z3

    Snapshot Title: z3
    Taken by: Andrew Murguia

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Trough cross beds?



  27. Tangential cross strata

    Snapshot Title: Tangential cross strata
    Taken by: Conor O'Toole

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Cross strata of stoss erosional current action with erosional boundary and hlams. Suggests a change in flow from fast to slower from left to right and bottom to top



  28. Coarse grain

    Snapshot Title: Coarse grain
    Taken by: Sian Riebe

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Evidence of tangential lee side, stoss erosional in lower half of snapshot. upper half boundary suggests a transition from coarser material to finer grained sandstone.

    Suggesting channel of braide...



  29. Trough Cross Strata

    Snapshot Title: Trough Cross Strata
    Taken by: Stephanie Lynn

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Likely evidence for trough cross strata. I interpret this to be a scour and fill pattern left by a migrating dune deposited by the flow in the deepest and/or fastest part of the channel. This sugges...



  30. 3D dunes

    Snapshot Title: 3D dunes
    Taken by: Rachel Barnes

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Migrating left to right



  31. Rip-up clast

    Snapshot Title: Rip-up clast
    Taken by: rhaynes

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    erosion of lower layer and a block is broken off and gravel is deposited on top before it can break apart.



  32. Alternating Bands of Gravel and Sand

    Snapshot Title: Alternating Bands of Gravel and Sand
    Taken by: Stephanie Lynn

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Alternating bands of gravel and sand. I interpret the gravel to represent mid channel deposits and the sand to represent shallower flow. This is suggestive of a migrating river channel.



  33. Scour & Fill Cross Strata

    Snapshot Title: Scour & Fill Cross Strata
    Taken by: Madison Smith

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Planar tabular cross strata indicative of either trough formation or channel cutting in. Channel erosion seems likely due to scale of convex strata



  34. z2

    Snapshot Title: z2
    Taken by: Andrew Murguia

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Trough cross-strata



  35. Cross Strata

    Snapshot Title: Cross Strata
    Taken by: Conor O'Toole

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    laminated beds of cross strata



  36. z1

    Snapshot Title: z1
    Taken by: Andrew Murguia

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Scale suggests:

    Trough cross-stratification indicating migrating dunes

    Note the evidence for scour



  37. HLams and Migrating Channel Edge

    Snapshot Title: HLams and Migrating Channel Edge
    Taken by: Stephanie Lynn

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Red bed or paleosol in contact with horizontal laminations indicating ankle deep flow; perhaps a proximal overbank deposit. Erosional surface on top of Hlams. Layer on top has right to left movement...



  38. Red Bed - Mudstone - Sandstone

    Snapshot Title: Red Bed - Mudstone - Sandstone
    Taken by: Sian Riebe

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Progression of oxidized red beds lying under heavily eroded mudstone - upper most layer less eroded, with evidence of planar h-lams. Possible evidence of distill overbank deposits.



  39. 3D Dunes

    Snapshot Title: 3D Dunes
    Taken by: Rachel Barnes

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    (?)



  40. Red to White to laminated beds

    Snapshot Title: Red to White to laminated beds
    Taken by: Conor O'Toole

    Image: Morrison Formation at Fremont Granary, east of Capitol Reef National Park, Utah
    Image Owner: Peter Lea



    Description:

    Red bed formation overlain by whiteish bed, overlain by sandstone



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