Delormes Gazetter Map Book is similiar to the Atlas Benchmark above, but has a list of what they call "Unique natural features" listed in the front with a quick write up of what is is and where to find it. From lava caves, hot springs, cinder cones, giant craters, faults/fissures, etc. Some good stuff in there.
Crack In The Ground
Here's an example- Called Crack in the Ground - it's a 2 mile long fault you can hike thru that's up to 100 feet deep, with many side fissures.
not my website but rather just a link to the type of thing you'll find in that list.