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63.8: Primary sedimentary structures

  • Page ID
    22485
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    PART I: OUTCROPS

    Here are 9 outcrops of rocks that show sedimentary structures of some kind. Thoroughly explore each scene to determine which sedimentary structures are present. (1) Identify them, and then (2) interpret them [i.e., (a) how they formed, (b) what they reveal about geopetal “up” direction or current direction].

    Outcrop 1:

    Outcrop 2:

    Outcrop 3:

    Outcrop 4:

    Outcrop 5:

    Outcrop 6:

    Outcrop 7:

    Outcrop 8:

    Outcrop 9:

    PART II: HAND SAMPLES

    Examine these 19 samples of rock showing various sedimentary structures and: (a) identify them and (b) interpret them.

    Sample 1:

    Sample 2:

    Sample 3:

    (Note: The little black curled lines here are the shells of small arthopods –shrimplike creatures– called ostracodes. Consider these hemispherical structures as sedimentary particles, as you would grains of sand.)

    Sample 4:

    Sample 5:

    Sample 6:

    Sample 7:

    Sample 8:

    Sample 9:

    Sample 10:

    Sample 11: (FYI, the little dash-shaped features that mainly run from left to right are gypsum casts)

    Sample 12:

    Sample 13:

    Sample 14:

    Sample 15:

    Sample 16:

    Sample 17:

    Sample 18:

    Sample 19:

    Please submit your answers to the instructor.


    This page titled 63.8: Primary sedimentary structures is shared under a CC BY-NC 4.0 license and was authored, remixed, and/or curated by Callan Bentley, Karen Layou, Russ Kohrs, Shelley Jaye, Matt Affolter, and Brian Ricketts (VIVA, the Virginia Library Consortium) via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.