Epsom Salt
Magnesium sulfate is a salt containing magnesium, sulfur and oxygen, with the formula MgSO4. It is often encountered as the heptahydrate sulfate mineral epsomite (MgSO4·7H2O), commonly called Epsom salt. It is named for a bitter saline spring from the town of Epsom in Surrey, England. Epsom salt occurs naturally as a pure mineral.
The 'pools' are created by the concentration of different mineral deposits. The colour can differ at different locations depending on the amounts and type of minerals present at a location.
During the summer, water can completely evaporate, depositing the solid minerals in large sediment rings, which results in the spotted look.
This little lake is part of an endorheic basin. An endorheic basin is a closed drainage basin that retains water and allows no outflow to other external bodies of water, such as rivers or oceans. This lake will fill during rain and run-off conditions like any other natural reservoir however the lake at this location must equilibrate through evaporation. These basins may also be referred to as closed or terminal basins.
History
In 1919, magnesium sulfate surface crystal from this location were shipped to Vancouver and prepared for market. At the different deposits in this area, 15 or 20 wooden buildings were erected including a number of comfortable dwelling houses for their workmen. A factory was eventually built in Ashcroft with a capacity of 1500 tonnes annually in 1942. (Thank you Gold Country for this information).
Uses
Medical
Magnesium sulfate (Epsom salts) is used in treating aches and pains. Oral magnesium sulfate is commonly used as a laxative. Studies have shown that magnesium sulfate can be used to reduce the symptoms of acute asthma. As well as many other medical uses.
Agriculture
In gardening and other agriculture, magnesium sulfate is used to correct a magnesium or sulfur deficiency in soil. It is most commonly applied to potted plants, or to magnesium-hungry crops, such as potatoes, roses, tomatoes, lemons, and peppers.
Other
It may be used as a coagulant for making tofu.
Magnesium sulfate is used as a brewing salt in beer production to adjust the ion content of the brewing water and enhance enzyme action in the mash or promote a desired flavor profile in the beer.
In order to log this earthcache as found, please email me the answers to the following questions (through my geocaching progile):
1) What is the length of the "lake" at this location? (Questions like this are used to let the cache owner know that you physically visited the location)
2) What colour are the magnesium sulfate crystals at this location?
3) How many inflows and outflows (creeks, rivers, etc.) can you see here? (read cache page for hint)
4) What is another name for an endorheic basin?
5) Is magnesium sulfate an organic or inorganic compound? (Remember that organic compounds typically contain carbon atoms)
6) If you are able to, take a look at a few crystals, what shape do they form? (salt crystals will form different shapes depending on the ions they contain)
7) (Optional) Post a photo with your log.
Sources:
http://en.wikipedia.org/wiki/Magnesium_sulfate
http://en.wikipedia.org/wiki/Endorheic_basin