2
$\begingroup$

I'm running a game where players can choose from a customizable list of traits and features for the terrain in the world, and one thing they've created is a saltwater swamp. However, they didn't purchase any coastal or ocean tiles, so they just have this weird, standalone, inland saltwater swamp.

Obviously the simplest thing to do is to change the rules or just give them some coast for free, but I was wondering whether there was some real-world geological/ecological mechanism that could cause a naturally occurring saltwater swamp to occur without being anywhere near another body of saltwater?

$\endgroup$
2
  • 1
    $\begingroup$ Inland salt water swamps are not weird and certainly not rare; a large part of Earth's dry land lies within endorheic basins. They are very common. Hamun Lake. Chott el Djerid. Great Salt Lake in the U.S. The mighty Lake Balkhash. $\endgroup$
    – AlexP
    Nov 8, 2022 at 18:35
  • 1
    $\begingroup$ @AlexP is right. I grew up next to the Great Salt Lake. Click here and scroll down to "Salt Marsh." The habitat is amazing, it's 100% land locked, and you can't drink the water. $\endgroup$
    – JBH
    Nov 8, 2022 at 18:52

6 Answers 6

5
$\begingroup$

You will need: 1. a rift system and 2. some time.

Consider the real world Jordan rift valley:

a satellite image of the Jordan rift valley

(image credit: Jacques Descloitres, MODIS Rapid Response Team, NASA/GSFC)

The dark blob on the left is the Mediterranean sea. The smaller dark blob surrounded by green at the top right is the Sea of Galilee, a freshwater lake. The larger dark blob at the center right is the Dead Sea, a famously hypersaline lake.

There is a theory that the Dead Sea was filled by flooding from the Mediterranean. It lies in a pretty unfriendly desert these days, but one could imagine a period in the life of such a lake where it was merely the regular kind of saline, and as its parent sea retreated but before it because too salty a little isolated salt-water ecosystem might arise. With the right conditions, it might transition to being hypersaline sufficiently slowly than halophytic plants and wildlife could arise there.

But that's not the only way... quoth the wikipedia page,

The Sea of Galilee is at risk of becoming irreversibly salinized by the salt water springs under the lake, which are held in check by the weight of the freshwater on top of them.

Salt water springs! Such things might let you have an inland saline body of water without it needing to also be an endorheic basin.

I also see references to places like Zuni Salt Lake, a lake that formed in a volcanic basin being not only quite salty but also having their own wildlife. Clearly the things you're requiring are not totally implausible, and there are multiple ways for them to arise.


And indeed, I've found something that is explicitly an inland saltwater marsh: Quivira National Wildlife Refuge. It is in Kansas, which is not particularly close to the sea. According to the Kansas Geological Survey, the salts come from underground salt deposits (eg. salty springs) and whilst the water is very brackish it isn't as saline as seas generally are. There's plenty of scope for handwaving, anyway. Unlike other salty lakes (especially in endorheic basins) it has vegetation, not just extremeophilic cyanobacteria, which probably makes it a bit nicer to visit.

$\endgroup$
1
  • $\begingroup$ Ooh! This has some very useful IRL examples, thanks! $\endgroup$
    – Onyz
    Nov 8, 2022 at 18:11
4
$\begingroup$

The Salt Marshes of the Great Salt Lake

Oddly, the answers so far don't really say that a salt marsh can exist. They explain the kinds of things you need to get one, but there's a better way!

The Great Salt Lake in Utah has salt marshes.

enter image description here
Photo of Great Salt Lake salt marsh courtesy Utah DWR.

Salt marsh occurs at the GSL in the form of salt grass and pickleweed complexes. Other associated marsh plants are alkali bulrush and Olney three-square bulrush. These plant communities persist in more saline soils and are often located in closed water basins that lose water through evaporation. Many times they occur outside WMA management units or where seeps occur within playa complexes. Salt marshes are often the extension of the freshwater wetlands as the water chemistry grades from fresh to brackish to salty. The vegetation height is usually shorter than some freshwater plants (e.g., cattail). Salt marshes are used by avocets and stilts for nesting and are favorite cover for common snipe. Geese graze pickleweed in the winter.

Give your players what they want. Yawn when you do it and mumble, "yeah, no problem!" Never let on that you have Worldbuilding on your side!

$\endgroup$
2
$\begingroup$

A lake In a desert environment, where the only way out for water is evaporation, will end up concentrating salts to the point of becoming salty.

Relevant example: the Dead Sea in Israel.

$\endgroup$
1
$\begingroup$

I'll second the other answers that for a salt lake you need an inland basin. However, for a swamp, you'll need a little more than that.

First, it needs to form just like the other salt lakes form - an inland basin, relatively dry, would be evaporating over many thousand years, creating a salt lake. We have many such lakes, but no salt swamps.

Second, a climate would need to shift. Your inland area should become more wet. No too wet to overflow and not too wet to dilute salt, but wet enough to create swamps. This wet period should be recent and could not last as long, geologically, as the previous dry period.

$\endgroup$
1
$\begingroup$

Ocean dried up.

http://jasoomiandreams.blogspot.com/2013/03/toonolian-marshes.html marsh

The Great TOONIALIAN MARSHES are located in the Red Planet’s northwest hemisphere. Home to the malagor, these marshes are the remnants of one of Barsoom’s five great oceans. These vast wetlands contain patches of dense jungle which are ruled by the fierce white ape.

“An oozy marsh through which are narrow water courses connecting occasional open water – little lakes, the largest of which could have comprised but two acres. This landscape extended as far as the eye could reach, broken by occasional islands. ..

Your world once had great oceans. The world is drying up and dying, as Barsoom is dying in Burrough's Mars books.

Cover art here is from Synthetic Men of Mars, my favorite. That is the hero back there in the boat, in his hormad body.

$\endgroup$
1
$\begingroup$

As L.Dutch said, you just need a low spot that rain water can get to to have a saltwater lake. There are examples in the US Southwest also. The California salt flats were once a salt lake.

The trouble to make a swamp, you would need plants and animals that can live in those conditions. We do have those but the conditions get too extreme too fast for those to really develop here. There are some beach grasses and mango trees that can survive sea water. However, a salt lake is much saltier than sea water. So, create/modify plants that can live there and there will be animals and insects that will live in/on the plants.

Another possibility is if you start with a salt lake that is very saline and then conditions changed in the past that allowed more fresh water to slowly arrive from the outside. The fresh water, being lighter that the high saline water will float on top. That means that the shallows at the edge will have mostly fresh water that is survivable. Then as the swamp gets deeper, there will be fewer and fewer plants that can survive far enough down to take root. This will create a hole in the center of the swamp. The only thing living in the center would be plants and animals that can float on the layer of fresh water.

The trouble with the last one is that all it takes is some massive disturbance to mix the salt with the fresh water and wipe out the life. This disturbance could be an earthquake or a flash flood that would bring in the fresh water fast enough to disturb the boundary layer.

$\endgroup$

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .