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Callan Bentley's Snapshots

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  1. Scale bar

    Snapshot Title: Scale bar
    Taken by: Callan Bentley

    Image: Martinsburg Formation, South Page Valley Road, Page County, Virginia
    Image Owner: Callan Bentley



    Description:

    Courtesy of the Virginia Division of Geology and Mineral Resources.



  2. Positive groove

    Snapshot Title: Positive groove
    Taken by: Callan Bentley

    Image: Martinsburg Formation, South Page Valley Road, Page County, Virginia
    Image Owner: Callan Bentley



    Description:

    What is this thing? A trace fossil? Its consistent width would suggest that. A tool mark? These are turbidite strata, after all - they are deposited in deep sea environments that aren't particularly r...



  3. Tool marks

    Snapshot Title: Tool marks
    Taken by: Callan Bentley

    Image: Martinsburg Formation, South Page Valley Road, Page County, Virginia
    Image Owner: Callan Bentley



    Description:

    Scratch, divots, scrapes and grooves made by current-entrained debris.



  4. Tool marks

    Snapshot Title: Tool marks
    Taken by: Callan Bentley

    Image: Martinsburg Formation, South Page Valley Road, Page County, Virginia
    Image Owner: Callan Bentley



    Description:

    This appear to be tool marks (little gouges made by solid particles as they are dragged along by currents).



  5. Trace fossil?

    Snapshot Title: Trace fossil?
    Taken by: Callan Bentley

    Image: Martinsburg Formation, South Page Valley Road, Page County, Virginia
    Image Owner: Callan Bentley



    Description:

    Or tool mark?



  6. Scale

    Snapshot Title: Scale
    Taken by: Callan Bentley

    Image: Martinsburg Formation, South Page Valley Road, Page County, Virginia
    Image Owner: Callan Bentley



    Description:

    Each vertical black and white bar is 10 cm tall.



  7. "Geology"

    Snapshot Title: "Geology"
    Taken by: Callan Bentley

    Image: Martinsburg Formation, South Page Valley Road, Page County, Virginia
    Image Owner: Callan Bentley



    Description:

    Center of this scale bar, courtesy of the Virginia Department of Geology and Mineral Resources.



  8. A closer look

    Snapshot Title: A closer look
    Taken by: Callan Bentley

    Image: Martinsburg Formation, Millner Road (near Deer Rapids Road), Shenandoah County, Virginia
    Image Owner: Callan Bentley



    Description:

    One of the graded beds from near this site has been imaged in macro GigaPan format. Check it out here:
    gigapan.com/gigapans/126104



  9. A closer look

    Snapshot Title: A closer look
    Taken by: Callan Bentley

    Image: Martinsburg Formation, Millner Road and Bethel Road, Shenandoah County, Virginia
    Image Owner: Callan Bentley



    Description:

    A block of rock collected at this site has been imaged in macro GigaPan format here:
    gigapan.com/gigapans/126104



  10. Cleavage and bedding

    Snapshot Title: Cleavage and bedding
    Taken by: Callan Bentley

    Image: Martinsburg Formation, Millner Road and Bethel Road, Shenandoah County, Virginia
    Image Owner: Callan Bentley



    Description:

    Cleavage dips steeply to the left (NW), while bedding dips moderately to the right (SE).



  11. Higher...

    Snapshot Title: Higher...
    Taken by: Callan Bentley

    Image: "Cub Sandstone" (Uppermost Martinsburg Formation), near Catherine Furnace, Virginia
    Image Owner: Callan Bentley



    Description:

    ...in the section, there is more sand and less mud. See for yourself:
    gigapan.com/gigapans/125616



  12. Lower...

    Snapshot Title: Lower...
    Taken by: Callan Bentley

    Image: "Cub Sandstone" (Uppermost Martinsburg Formation), near Catherine Furnace, Virginia
    Image Owner: Callan Bentley



    Description:

    ...in the section, there is less sand and more mud. See for yourself:
    gigapan.com/gigapans/125617



  13. Bedding vs. cleavage

    Snapshot Title: Bedding vs. cleavage
    Taken by: Callan Bentley

    Image: "Cub Sandstone" (Uppermost Martinsburg Formation), near Catherine Furnace, Virginia
    Image Owner: Callan Bentley



    Description:

    Bedding is upright (vertical bands showing different colors and textures), while cleavage dips steeply to the right (east).



  14. Bedding vs. cleavage II

    Snapshot Title: Bedding vs. cleavage II
    Taken by: Callan Bentley

    Image: "Cub Sandstone" (Uppermost Martinsburg Formation), near Catherine Furnace, Virginia
    Image Owner: Callan Bentley



    Description:

    Bedding upright; cleavage dipping steeply to the right (east).



  15. Spheroidal weathering

    Snapshot Title: Spheroidal weathering
    Taken by: Callan Bentley

    Image: "Cub Sandstone" (Uppermost Martinsburg Formation), near Catherine Furnace, Virginia
    Image Owner: Callan Bentley



    Description:

    A nice example.



  16. Joints

    Snapshot Title: Joints
    Taken by: Callan Bentley

    Image: "Cub Sandstone" (Uppermost Martinsburg Formation), near Catherine Furnace, Virginia
    Image Owner: Callan Bentley



    Description:

    Cutting more or less orthogonally across the sandstone bed (shale both upsection (left) and downsection (right)).



  17. 1 cm

    Snapshot Title: 1 cm
    Taken by: Callan Bentley

    Image: "Cub Sandstone" (Uppermost Martinsburg Formation), near Catherine Furnace, Virginia
    Image Owner: Callan Bentley



    Description:

    One centimeter



  18. Sense of scale

    Snapshot Title: Sense of scale
    Taken by: Callan Bentley

    Image: "Cub Sandstone" (Uppermost Martinsburg Formation), near Catherine Furnace, Virginia
    Image Owner: Callan Bentley



    Description:

    In inches and centimeters.



  19. Bedding vs. cleavage.

    Snapshot Title: Bedding vs. cleavage.
    Taken by: Callan Bentley

    Image: "Cub Sandstone" (Uppermost Martinsburg Formation), near Catherine Furnace, Virginia
    Image Owner: Callan Bentley



    Description:

    Bedding upright; cleavage dipping to the right.



  20. Spheroidal weathering

    Snapshot Title: Spheroidal weathering
    Taken by: Callan Bentley

    Image: "Cub Sandstone" (Uppermost Martinsburg Formation), near Catherine Furnace, Virginia
    Image Owner: Callan Bentley



    Description:

    A nice example.



  21. 1 cm

    Snapshot Title: 1 cm
    Taken by: Callan Bentley

    Image: "Cub Sandstone" (Uppermost Martinsburg Formation), near Catherine Furnace, Virginia
    Image Owner: Callan Bentley



    Description:

    A second sense of scale.



  22. 1 cm
  23. Asterisk

    Snapshot Title: Asterisk
    Taken by: Callan Bentley

    Image: Pillow Basalts at Kirby Cove
    Image Owner: Robin Rohrback-Schiavone



    Description:

    between 5 pillows



  24. Edge of a pillow

    Snapshot Title: Edge of a pillow
    Taken by: Callan Bentley

    Image: Pillow Basalts at Kirby Cove
    Image Owner: Robin Rohrback-Schiavone



    Description:

    Note the radial fracture array.



  25. An original upright fold...

    Snapshot Title: An original upright fold...
    Taken by: Callan Bentley

    Image: Recumbent anticline in the Edinburg Formation, Page County, Virginia
    Image Owner: Callan Bentley



    Description:

    ...that was sheared westward into recumbency? That's the interpretation of Steve Whitmeyer (JMU) and his students. See discussion in the 2012 VGFC field guide:
    csmres.jmu.edu/Geollab/Whitmeyer Will open in a new tab or window...



  26. An overturned upright fold?

    Snapshot Title: An overturned upright fold?
    Taken by: Callan Bentley

    Image: Recumbent anticline in the Edinburg Formation, Page County, Virginia
    Image Owner: Callan Bentley



    Description:

    That's the interpretation of Steve Whitmeyer (JMU) and his students. See discussion in the 2012 VGFC field guide:
    csmres.jmu.edu/Geollab/Whitmeyer/web/documents/VGFC%202012.pdf Will open in a new tab or window



  27. Bedding plane

    Snapshot Title: Bedding plane
    Taken by: Callan Bentley

    Image: Recumbent anticline in the Edinburg Formation, Page County, Virginia
    Image Owner: Callan Bentley



    Description:

    This bed is upright.



  28. Another view

    Snapshot Title: Another view
    Taken by: Callan Bentley

    Image: Recumbent anticline in the Edinburg Formation, Page County, Virginia
    Image Owner: Callan Bentley



    Description:

    This a more zoomed-out view of this same site here: gigapan.com/gigapans/125604



  29. Stylolites

    Snapshot Title: Stylolites
    Taken by: Callan Bentley

    Image: Recumbent anticline in the Edinburg Formation, Page County, Virginia
    Image Owner: Callan Bentley



    Description:

    Hidden in the shadows.



  30. Calcite veins

    Snapshot Title: Calcite veins
    Taken by: Callan Bentley

    Image: Recumbent anticline in the Edinburg Formation, Page County, Virginia
    Image Owner: Callan Bentley



    Description:

    White on the gray limestone background.



  31. Cleavage refraction

    Snapshot Title: Cleavage refraction
    Taken by: Callan Bentley

    Image: Recumbent anticline in the Edinburg Formation, Page County, Virginia
    Image Owner: Callan Bentley



    Description:

    Note the different angles cleavage takes as it traverses these beds.



  32. Cleavage/bedding intersection

    Snapshot Title: Cleavage/bedding intersection
    Taken by: Callan Bentley

    Image: Recumbent anticline in the Edinburg Formation, Page County, Virginia
    Image Owner: Callan Bentley



    Description:

    Maybe some of the cleavage is being exploited as a zone of weakness to facilitate outer arc extension, too.



  33. Pencil for scale

    Snapshot Title: Pencil for scale
    Taken by: Callan Bentley

    Image: Recumbent anticline in the Edinburg Formation, Page County, Virginia
    Image Owner: Callan Bentley



    Description:

    This is a mechancial pencil with 1-cm bars along the side.



  34. A closer view

    Snapshot Title: A closer view
    Taken by: Callan Bentley

    Image: Recumbent anticline in the Edinburg Formation, Page County, Virginia
    Image Owner: Callan Bentley



    Description:

    I shot another GigaPan closer in (fewer trees in the way): gigapan.com/gigapans/125605



  35. Outcrop maintenance

    Snapshot Title: Outcrop maintenance
    Taken by: Callan Bentley

    Image: Skinners Butte Columnar Basalt
    Image Owner: Robin Rohrback-Schiavone



    Description:

    Good work! A victory for the rocks over the pesky vegetation that would obscure them.



  36. Arrest lines

    Snapshot Title: Arrest lines
    Taken by: Callan Bentley

    Image: Skinners Butte Columnar Basalt
    Image Owner: Robin Rohrback-Schiavone



    Description:

    Fracture propagation arrest ('stopping') lines on the sides of the column. Each of these represents the spot where the basalt went from being unbroken (below) to broken (above).



  37. A job for...

    Snapshot Title: A job for...
    Taken by: Callan Bentley

    Image: Recumbent anticline in the Edinburg Formation, Page County, Virginia
    Image Owner: Callan Bentley



    Description:

    ...the Farm Boss.



  38. Recumbent syncline

    Snapshot Title: Recumbent syncline
    Taken by: Callan Bentley

    Image: Recumbent anticline in the Edinburg Formation, Page County, Virginia
    Image Owner: Callan Bentley



    Description:

    Fold faces the opposite direction of the "main" fold in this quarry.



  39. Cleavage refraction

    Snapshot Title: Cleavage refraction
    Taken by: Callan Bentley

    Image: Recumbent anticline in the Edinburg Formation, Page County, Virginia
    Image Owner: Callan Bentley



    Description:

    Compare the cleavage orientation from left to right across this snapshot.



  40. Outer arc extension

    Snapshot Title: Outer arc extension
    Taken by: Callan Bentley

    Image: Recumbent anticline in the Edinburg Formation, Page County, Virginia
    Image Owner: Callan Bentley



    Description:

    These extensional fractures are very similar to those seen at another overturned anticline: Swift Dam. Check it out and compare the two: gigapan.com/gigapans/83143



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