• @skysurfer
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    51 year ago

    Pardon my ignorance, but any idea what the two darker layers are about halfway down the image?

    • @[email protected]
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      fedilink
      61 year ago

      I find judging by the picture alone difficult, but then again this isn’t my field of expertise. However, this might be a pseudogley. The brown strips you see are areas where oxygen and non oxygen milieus clash within the soil, thus forming rust. The layers could stem from prolonged episodes of relatively constant water saturation of the soil, thus creating a stable frontier between air and water enabling rust. It would be interesting to see the vegetation on top, as this would probably paint a clearer picture.

      • Track_ShovelOPM
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        fedilink
        English
        4
        edit-2
        1 year ago

        You’re right, but the wording you’re using is different than what’s used here (but it is correct).

        The stripes and rust colours are referred to mottling here. They are caused, as you accurately describe, by intermittent saturation and aeration of the soil. During saturated conditions, Fe2+ is deposited as it’s labile. Once things dry out again it turns to its Fe3+ form and oxidizes.

        Once formed mottles are permanent features. Even if the local moisture regime changes the legacy mottling will stay.

        Vegetation looks like it’s Ag land.

        @[email protected]

        • @[email protected]
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          fedilink
          31 year ago

          I’m sorry if I didn’t adhere to some standard, English isn’t my native language so I had to translate the sometimes weird terminology used around here. We just use it for the description of forest soil.

          • Track_ShovelOPM
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            fedilink
            English
            31 year ago

            No worries! I’ve just never seen the terminology before. Your concepts are spot on though

    • @ladicius
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      21 year ago

      I’m interested, too! Maybe fires?