Utah rock pattern identification - looks like small craters This formation was found in the Capital Reef area of Southern Utah (38.2970546, -111.2979319).

There wasn't just one, but several of these small crater formations all over the area. All of them had the same basic structure: a ring of raised rock with fins, surrounding a depression that seems to be at about the same level as the surrounding rock. The rings were darker in color with lighter fins, and the depressions in the middle are lighter in color. All about 20-40 cm in diameter. The rock they are in is most likely a sandstone.

Does anybody know what this is and how it was formed?

The first image is a nearly straight down view, and the second image is an angled image to highlight the fins that ring the depression.

Keys for scale (there wasn't a banana available ;) )
Relief features made by microbial mats which were gelatinous. The ridges and fins are thought to be caused by small currents that flowed through the umbrella like bodies of these ancient bacteria.