I’ve been going on about some enigmatic, circular, depressions in New Mexico for a few months now. The consensus among those who are skeptical of impact events is that they are all related to karst geology. And that they are all just sinkholes. Many of them are probably just that.
I found a new sinkhole at 32.731966, -104.127823 that would seem to be supportive of that view. It’s in an oil field. And a quick check of the location with Google Earth’s historical image feature reveals that it wasn’t there in 2005. It is almost certainly the result of a water injection well gone wrong. So we can say it’s man-made.
It’s a common cliché that the best place to hide a tree is in a forest. Likewise, the best place to hide a field of small craters is in limestone. No self respecting uniformitarian conditioned geologist would look twice at the thousands of circular depressions in New Mexico.
However, this man-made, but certifiable, sinkhole can be used as a standard example of the morphology of a true sinkhole that others in the state can be compared to.
The injection well created a cavern by dissolving a void deep in the limestone below. Once enough limestone was dissolved, and removed, the the rock was no longer strong enough to support the weight above. And the surface collapsed into the resulting cave, forming a classic sinkhole.
The water from the injection well accelerated the rate at which the limestone dissolved. And the resulting cave would have grown at hundreds of times the erosion rate expected by normal ground water flow. But the collapse itself, and resulting sinkhole, were nevertheless a perfectly natural karst collapse. Making it a good standard model of a sinkhole.
And since all material movement was downwards, there is nothing in the process that formed that sinkhole that could account for raised rims, or overlapping craters with raised rims between them. Nor is there anything in the process we see there that could account for materials thrown outside the hole.
Take a close look at the area shown in the image below. Note the raised rims. Especially between some of the ones that overlap. I won’t speak for others. But as for me, I remain convinced that these things are a field of small impact craters.