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Callan Bentley's Snapshots

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  1. Rip-ups

    Snapshot Title: Rip-ups
    Taken by: Callan Bentley

    Image: Grinnell Formation Quartzite
    Image Owner: Robin Rohrback



    Description:

    What do these mud-chip rip-up clasts suggest about the depositional energy (current strength) at this site over time?



  2. O2

    Snapshot Title: O2
    Taken by: Callan Bentley

    Image: Grinnell Formation Quartzite
    Image Owner: Robin Rohrback



    Description:

    Were these sediments deposited under oxygenated or anoxic conditions? What evidence supports your conclusion?



  3. Crossbeds

    Snapshot Title: Crossbeds
    Taken by: Callan Bentley

    Image: Grinnell Formation Quartzite
    Image Owner: Robin Rohrback



    Description:

    Is the sample right-side-up or up-side-down? How do you know? Which way was the sediment-depositing current flowing when these grains were laid down? What evidence would you cite in support of your in...



  4. Mudchips & crossbeds

    Snapshot Title: Mudchips & crossbeds
    Taken by: Callan Bentley

    Image: Grinnell Formation Quartzite
    Image Owner: Robin Rohrback



    Description:

    Which way was the current flowing? How had the depositional energy changed?



  5. 1 cm

    Snapshot Title: 1 cm
    Taken by: Callan Bentley

    Image: Grinnell Formation Quartzite
    Image Owner: Robin Rohrback



    Description:

    This scale bar conveys a sense of how big the rock sample is. The blue bars are each 1 centimeter wide.



  6. Sutured grain boundary

    Snapshot Title: Sutured grain boundary
    Taken by: Callan Bentley

    Image: Flat Pebble Conglomerate, Gros Ventre Formation
    Image Owner: Robin Rohrback



    Description:

    Evidence of pressure solution



  7. 120 degree fractures

    Snapshot Title: 120 degree fractures
    Taken by: Callan Bentley

    Image: Flat Pebble Conglomerate, Gros Ventre Formation
    Image Owner: Robin Rohrback



    Description:

    Some of the pebbles are cracked due to bedding-perpendicular loading and bedding-parallel extension. σ1 > σ2 = σ3



  8. 1 cm

    Snapshot Title: 1 cm
    Taken by: Callan Bentley

    Image: Flat Pebble Conglomerate, Gros Ventre Formation
    Image Owner: Robin Rohrback



    Description:

    This bar serves as a sense of scale.



  9. Scale

    Snapshot Title: Scale
    Taken by: Callan Bentley

    Image: Massanutten Sandstone
    Image Owner: Callan Bentley



    Description:

    This pencil serves as a sense of scale. The black bars along its side are each 1 cm in length.



  10. Scale

    Snapshot Title: Scale
    Taken by: Callan Bentley

    Image: Massanutten Sandstone
    Image Owner: Callan Bentley



    Description:

    This pencil serves as a sense of scale. The black bars along its side are 1 cm in length each.



  11. Scale

    Snapshot Title: Scale
    Taken by: Callan Bentley

    Image: Massanutten Sandstone
    Image Owner: Callan Bentley



    Description:

    This pencil serves as a sense of scale. The black bars on its side are each 1 cm long.



  12. Blocky "needles"

    Snapshot Title: Blocky "needles"
    Taken by: Callan Bentley

    Image: Stylolite in Helderberg Group limestone, West Virginia
    Image Owner: Callan Bentley



    Description:

    Stylolitic surface in detail. Note apparent accumulation of clay (pelitic non-soluble material) along stylolite surface.



  13. Stylolite "needle"

    Snapshot Title: Stylolite "needle"
    Taken by: Callan Bentley

    Image: Stylolite in Helderberg Group limestone, West Virginia
    Image Owner: Callan Bentley



    Description:

    Rock has dissolved along this surface, causing interpenetration of the two strata.



  14. Fossil

    Snapshot Title: Fossil
    Taken by: Callan Bentley

    Image: Stylolite in Helderberg Group limestone, West Virginia
    Image Owner: Callan Bentley



    Description:

    Shelly material



  15. 1 cm

    Snapshot Title: 1 cm
    Taken by: Callan Bentley

    Image: Stylolite in Helderberg Group limestone, West Virginia
    Image Owner: Callan Bentley



    Description:

    Scale



  16. Sandstone pebble

    Snapshot Title: Sandstone pebble
    Taken by: Callan Bentley

    Image: Shawangunk Conglomerate, Pennsylvania
    Image Owner: Callan Bentley



    Description:

    You can see the grains inside it.



  17. Flush grain boundaries

    Snapshot Title: Flush grain boundaries
    Taken by: Callan Bentley

    Image: Shawangunk Conglomerate, Pennsylvania
    Image Owner: Callan Bentley



    Description:

    Evidence of pressure solution



  18. 1 cm

    Snapshot Title: 1 cm
    Taken by: Callan Bentley

    Image: Shawangunk Conglomerate, Pennsylvania
    Image Owner: Callan Bentley



    Description:

    Scale



  19. Phenocryst

    Snapshot Title: Phenocryst
    Taken by: Callan Bentley

    Image: Bishop Tuff
    Image Owner: Robin Rohrback



    Description:

    Quartz (note the conchoidal fracture).



  20. Lithic

    Snapshot Title: Lithic
    Taken by: Callan Bentley

    Image: Bishop Tuff
    Image Owner: Robin Rohrback



    Description:

    Fragment of pre-existing rock, caught up in the pyroclastic surge.



  21. Scale

    Snapshot Title: Scale
    Taken by: Callan Bentley

    Image: Bishop Tuff
    Image Owner: Robin Rohrback



    Description:

    This box is 1 cm wide.



  22. Sample

    Snapshot Title: Sample
    Taken by: Callan Bentley

    Image: Rockfish Gap, Virginia
    Image Owner: Callan Bentley



    Description:

    To see a piece of the Catoctin greenstone from this site in "macro" GigaPan view, click here: gigapan.com/gigapans/149431



  23. Sample

    Snapshot Title: Sample
    Taken by: Callan Bentley

    Image: Rockfish Gap, Virginia
    Image Owner: Callan Bentley



    Description:

    To see a piece of the Catoctin greenstone from this site in "macro" GigaPan view, click here: gigapan.com/gigapans/149431



  24. 1 cm Scale

    Snapshot Title: 1 cm Scale
    Taken by: Callan Bentley

    Image: Chip suite, El Paso region geology
    Image Owner: Callan Bentley



    Description:

    This box is 1 centimeter across



  25. Partly lithified cluster

    Snapshot Title: Partly lithified cluster
    Taken by: Callan Bentley

    Image: Coarse Ooids
    Image Owner: Robin Rohrback



    Description:

    oolitic limestone in the making.



  26. Pyrite

    Snapshot Title: Pyrite
    Taken by: Callan Bentley

    Image: Flat Pebble Conglomerate, Gros Ventre Formation
    Image Owner: Robin Rohrback



    Description:

    Small pyrite crystal, surrounded by a rusty aura.



  27. Scale

    Snapshot Title: Scale
    Taken by: Callan Bentley

    Image: Ball and pillow
    Image Owner: Callan Bentley



    Description:

    This is 1 cm long.



  28. Sample collected here

    Snapshot Title: Sample collected here
    Taken by: Callan Bentley

    Image: Ball and pillow
    Image Owner: Callan Bentley



    Description:

    :)



  29. Square hole

    Snapshot Title: Square hole
    Taken by: Callan Bentley

    Image: Mudcracks from the Belt Supergroup
    Image Owner: Robin Rohrback



    Description:

    Suspiciously square shaped... former halite cast? or just geo-pareidolia?



  30. Book return

    Snapshot Title: Book return
    Taken by: Callan Bentley

    Image: Fort Valley Community Center and Library
    Image Owner: Callan Bentley



    Description:

    Drop box!



  31. Scale

    Snapshot Title: Scale
    Taken by: Callan Bentley

    Image: Ash and Lapilli from Kilbourne Hole
    Image Owner: Robin Rohrback



    Description:

    Petri dish diameter is 9 cm.



  32. Laminations

    Snapshot Title: Laminations
    Taken by: Callan Bentley

    Image: Witvlei Group Stromatolites
    Image Owner: Callan Bentley



    Description:

    Microbial mats growing upward (toward sunlight) give this rock its distinctive "onion-skin" domes.



  33. Scale

    Snapshot Title: Scale
    Taken by: Callan Bentley

    Image: Witvlei Group Stromatolites
    Image Owner: Callan Bentley



    Description:

    This blue bar is 1 cm long.



  34. Sample

    Snapshot Title: Sample
    Taken by: Callan Bentley

    Image: Martinsburg Formation exposed at Staunton, Virginia
    Image Owner: Callan Bentley



    Description:

    A sample of graywacke collected at this site may be seen in macro view here:
    gigapan.com/gigapans/145682



  35. Sample

    Snapshot Title: Sample
    Taken by: Callan Bentley

    Image: Martinsburg Formation exposed at Staunton, Virginia
    Image Owner: Callan Bentley



    Description:

    A sample of graywacke collected at this site may be seen in macro view here:
    gigapan.com/gigapans/145682



  36. Sample

    Snapshot Title: Sample
    Taken by: Callan Bentley

    Image: Martinsburg Formation exposed at Staunton, Virginia
    Image Owner: Callan Bentley



    Description:

    A sample collected at this site may be seen in macro view here:
    gigapan.com/gigapans/145682



  37. Scale

    Snapshot Title: Scale
    Taken by: Callan Bentley

    Image: Folded calc-silicate
    Image Owner: Callan Bentley



    Description:

    This bar is 1 centimeter long.



  38. P-sol

    Snapshot Title: P-sol
    Taken by: Callan Bentley

    Image: Hibriten Mylonite
    Image Owner: Robin Rohrback



    Description:

    Pressure solution here?
    Garnet porphyroblast impinging on quartz ribbon below it.



  39. Garnet

    Snapshot Title: Garnet
    Taken by: Callan Bentley

    Image: Hibriten Mylonite
    Image Owner: Robin Rohrback



    Description:

    Porphyroblast with reaction rim.



  40. Tailed porphyroclast

    Snapshot Title: Tailed porphyroclast
    Taken by: Callan Bentley

    Image: Hibriten Mylonite
    Image Owner: Robin Rohrback



    Description:

    Quartz-feldspar domain with "tails" along the plane of foliation.



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