What are those weird circles in the water??
|Source: http://www.geologyin.com/2014/12/the-spotted-lake.html. Provenance is not clear...if this is your photo please let me know for proper attribution.|
So what the heck is going on here? I will let you know below in case you want to think about it for a minute...
|Source:https://tripandtravelblog.com/the-beautiful-spotted-lake-of-canada/ Provenance is not clear, if this is your photo, please let me know for proper attribution|
The answer is....I don't particularly know. Well, I know some things. The lake is in an endorheic basin, and as such does not receive enough precipitation to fill the basin it occupies. Thus it dries up rather than flowing through an outlet. The drying concentrates the soluble minerals in the water. The mineral deposits are primarily magnesium sulfates (the mineral epsomite) along with calcium sulfate (gypsum), and sodium sulfate (mirabilite or thenardite). The source of the sulfates are copper minerals in the surrounding hills. Magnesium is provided by local dolomite exposures.
What I admit to not understanding is the formation of the circles and pools. The boundaries of the circles is a dark organic rich mud that develops an efflorescence of white crystals when dry. I wonder if the circles are related to periglacial processes related to frigid conditions in winter, and I would dearly love to be educated about this!
The epsomite has been mined at times a century ago, but the lake is sacred to the local indigenous First Nations people, the Okanagan Syilx. They came into ownership of the lake in 2001, and for the time being it can only be observed from the hills above on the highway, which is reasonable. One can imagine the damage that could be done by unfettered visits of ignorant tourists. The "European" name of the pond is Spotted Lake, but it has been known for centuries by the Syilx as Kliluk Lake.