Kilmore said:
I'm working my way south while making my fantasy world. I'm in the deserts now. It has occured to me that salt flats are a feature of deserts that aren't often seen in games, and I was wondering...
1. What are they like, environment wise?
It depends on how dry they are. Typically it's a crust of salt over a layer of mud, and if there's enough water in the mud, the combination can be almost impossible to walk on. People have died of heat and exhaustion, even in fairly recent times, trying to walk through some of the salt flats in Death Valley. Around the edges of the salt flat, or on a very dry salt flat, it will be normal ground with a layer of salt on top.
In the heart of a salt flat, there may be a salty lake, although it may only be there after rain.
2. What are their natural causes? What about supernatural causes?
Salt flats generally occur in "blind" valleys and catchment areas where rain water can't escape to the sea (or escapes very slowly), like Death Valley, the great basin of Utah, and many of the catchment areas of Nevada. They're also found in the deserts of the Middle East and Australia (Lake Eyre is a particularly large one in South Australia).
Water flows to the lowest point of these catchment areas, where it basically sits until it evapourates, leaving the salts it has dissolved out of the rocks that it flows over on the ground. Repeat this over many years of rain, and you can get a thick buildup of salts.
As for supernatural causes, anything which can cause water to evapourate or be destroyed would be an obvious cause (an artifact buried in a valley which has a side effect of destroying water in a wide area?). They could be related to portals from a para-elemental plane of salt, or ooze.
3. Aside from salt, is there anything that can be gotten from there? Any use a nation could have for them?
There is water, at least some of the time, which in combination with spells like purify water may give a community a water supply in the desert. If there are perennial streams which feed a salt lake, then you don't even need the spells. Also, where there's water, there's life, so it may be a food source.
Also, the salts in salt flats often are more than just sodium chloride. IRL salt flats have been, and are still, mined for things like borax. Maybe the salt from salt flats make good spell components?
4. I bet anything that dropped dead in the salt flats would have a better chance of being mummified by the minerals than normal. Any ideas for Salt Mummies?
Maybe, maybe not. I believe that natural mummification requires extreme dryness, and salt flats are one of the few areas in a desert where it routinely gets wet. Nevertheless, maybe instead of mummy rot, salt mummies cause a disease which gradually sucks the water out of your body, leaving you a desiccated corpse if you don't get healing.
5. Where are they at in the real world? Utah, of course, but where else?
See above: Utah, Nevada and California, the Sahara and Middle East, and Australia, at least. Basically, they occur anywhere where water pools, and the rate of evapouration is greater than the rate of inflow (at least most of the time).
Hope this helps.
Corran