Rock Questions

[tmancos]

Hello. I'm new, and looking for some help identifying and/or explaining a rock I found.

I live in the Intermountain West, in the foothills of a mountain range. Today I was in a reasonably remote and sparsely populated natural area in the desert foothills, where I wouldn't expect to find many man made stone objects aside from arrowheads and pottery chardes, but I found this interesting rock, that I'm seeking help understanding.

I haven't measured it, but it appears to be about 8"x12"x5"ish.

[SurfaceHunter]

To me and I could be way off but it looks like a type of concrete maybe a old type from a old home.

[tmancos]

It honestly looks like some kind of sandstone common in this area.

[Hoss]

Welcome to arrowheads.com . That area was once sand dunes wind created the rolling effect over time the sand became sandstone when it was lithified through geologic process . Natural in my opinion but still a cool find and I would have brought it home too.

[Hoss]

Photo of the Sahara I found on the net. https://www.wildlandtrekking.com/blog/navajo-sandstone/

[painshill]

Welcome to arrowheads.com

Those look to me like 'sole marks' of the kind known as 'flute casts'. You'll find them in sedimentary rocks known generically as 'turbidites', which are usually silty sandstones where rivulet currents of water have created little channels in the sediments before they lithified. When they're indented, you're looking at the top layer of a stratum, but you'll find the same impressions in reverse on the base layer of the stratum on top of it. This kind of thing:



[Picture by vtbuck223]

[Hoss]

Thank you Roger I stand corrected. I still say it is a naturally occurring formation of sandstone I was mistaken in how it got that way. .

[SGT.Digger]

Hard to see with all the lichens. Could it be a fossil impression of a giant clam? I’ve seen monster clams in Hawaii (should have gotten them they were free at a home renovation thought they were cast fakes didn’t realize they were real)

[painshill]

Not a fossil clam. Sole marks from water movement in sediments.

[tmancos]

Much thanks.