This is a very cool graphic from National Geographic showing how these most unusual rock formations of western Madagascar formed (carved by groundwater erosion, not by precipitation).
I've embedded a smaller gif to save my bandwidth; those interested in the process can read the details in this larger version
(I'll bet when you woke up this morning you didn't even know what a grike was. Neither did I.)
Via Geology Rocks.
A tip of the hat to Randomscrub, who notes that Titan also has karst topography
--Thank you. :)
Looks like a similar phenomenon on Titan:ReplyDelete
Yes, I'm a geek.
There's an impressive limestone pavement in Malham, Yorkshire - England. While the grikes are the fissures, the remaining pavement rock is called a 'clint'. Some pictures here: http://www.gowilder.org.uk/geog/WASP/malham.htmReplyDelete