(Edit: adjusted the color saturation and sharpness a bit.)
This was done for a project of Athas.org that I'm not certain of the status of any longershould be coming out this year--the long-awaited "Secrets of the Deadlands" setting expansion. This was originally meant to be used as the map, then it was decided it would be used as part of the cover, but I'm uncertain what it's final use in the book will be.
For those interested: The Dead Lands are an area of the dying desert world of Athas which were covered by a wave of elemental obsidian, burying whole cities and kingdoms under black glass. Today, the Dead Lands are populated by numerous kingdoms of the undead: the risen bones and wandering spirits of those buried.
This map is based in part on the original maps of Athas created by TSR, Inc. and with input from the Athas.org team. There are a number of large features that can be seen here: two dead seas buried under the obsidian, a vast stretch of contested ground covered by scattered bones, broken mountains made where the obsidian wave splashed against low hills, and icy domes in the south.
What most people don't know is that while obsidian is a dark, glassy substance, it isn't always black and often contains various colors depending upon mineral and chemical impurities. To get the variations you see here, I utilized various obsidian textures from photo stock to suggest the features, shapes, and impurities of the various areas of the Dead Lands.
To create this I used Photoshop and various brushes, plus the above-mentioned textures. Enjoy!