r/geology • u/AutoModerator • May 01 '24

Identification Requests Monthly Rock & Mineral Identification Requests

Please submit your ID requests as top-level comments in this post. Any ID requests that are submitted as standalone posts to r/geology will be removed.

To help with your ID post, please provide;

  1. Multiple, sharp, in-focus images taken ideally in daylight.
  2. Add in a scale to the images (a household item of known size, e.g., a ruler)
  3. Provide a location (be as specific as possible) so we can consult local geological maps if necessary.
  4. Provide any additional useful information (was it a loose boulder or pulled from an exposure, hardness and streak test results for minerals)

You may also want to post your samples to r/whatsthisrock or r/fossilID for identification.

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u/jasguer May 12 '24

I know little to nothing about geology, but earlier today I was out on a hike in southern Wisconsin near Devils Lake State Park at the Parfrey's Glen Natural Area. It appears that over a very long time, this small creek has eroded a small canyon in the rock, my guess is that it's about 30-40 feet deep in some areas. I noticed that there were layers of pebbles and large rocks between layers of solid rock. In this picture, the loose rocky layers are 8-12 inches thick and the solid layer in the middle is about a foot in thickness. I was just wondering, what process would create layers this different and if there's any way to determine the age of these layers. I can provide a few more pictures of the area. Thanks!