Wednesday, June 6, 2012

A Wednesday Whatsit: What is it?

A pair of puzzles for a Wednesday afternoon. What are these???

Location is on the Colorado Plateau, southwestern part; the top photo is about three feet across, while the bottom photo is 3-4 feet across...
First prize is bragging rights!

8 comments:

Ron Schott said...

#1: Boxwork type veins (from a concretion?)

#2: Tool marks (trace fossil on a sandy(?) substrate.

Lockwood said...

Upper one look like inverted cast of mudcracks- sand infills cracks, and after lithifcation, withstands weathering better than underlying mudstone. Lower one less certain about, but looks like some kind of drag marks. Amphibian/reptile tail(s)?

Callan Bentley said...

First one is cast of dino footprint in mudcracked mud, with the cracks radiating out from the footprint like a spider web, indicating the footprint came first or contemporaneously with the stresses that caused the mud to crack. Not sure about the second one...

Elizabeth R said...

The first is inverted mudcracks. The second are swimming tracks from a dinosaur.

Randy A. said...

I agree with Ron Schott...

blog with no name said...

Top one looks like "worm burrows" in the Kaibab Limestone.

meg said...

1. I agree with Callan, I didn't notice the footprint until he pointed that out.

2. Trace fossil? Maybe feeding traces (like from a trilobite?)

biobabbler said...

I have to say I really don't know, but these photographs are MOST delightful to contemplate. Imagination (esp. since I am a geology ignoramus) is a fun muscle to exercise. That 1st one (ignoring all the erudite guesses your blog visitors have posted) is a TOTAL mind bender!

The 2nd looks a bit like BIG ol' leaves, but guessing from above comments, not likely. =)