La Sal del Rey
La Sal del Rey, sometimes ungrammatically called El Sal del Rey and also known as La Purificación, is a salt lake. The lake has a circumference of five miles, is a mile long, and ranges from three to four feet deep. The bed consists of rock-crystal salt composed of 99.0897 percent sodium chloride. The large salt deposit, the undetermined depth, has no connection with any other body of water; how it was formed is unknown. Salt blocks removed from any spot in the lake are quickly replenished, often in two or three days, as the water is shifted by the predominantly southeastern winds of the area. Engineers estimate that the lake holds four million tons of salt. The water may dry out completely or, in periods of much rainfall, be more than ten feet deep.
La Sal del Rey is a hypersaline lake atop an estimated four million tons of salt. The lake is 10 times saltier than the ocean and was a valuable source of salt for Native Americans, Spanish explorers, and Western pioneers.
A Quick Chemistry Lesson
Sodium Chloride (NaCl) results from a chemical bonding between sodium and chlorine metal atoms. All atoms with incomplete electron valence shells need to fill their outer shells and can bond with other atoms under the right conditions. Chlorine has 7 electrons in its outer valence shell and only needs 1 more electron to complete its outer shell. Conversely, sodium has only 1 electron in its outer valence shell and still needs 7 more electrons to complete its shell. Thus, when sodium and chlorine come into contact, the conditions are right to fill one another’s outer valence shells. It is easier to transfer 1 electron than 7, so the extra electron from sodium moves into the outer valence shell of chlorine, completing both electron shells and chemically bonding the two atoms together. The element resulting from the chemical bonding, sodium chloride, is more commonly referred to as salt and is the object of interest in pursuing this EarthCache.
Hypersaline Lake
A hypersaline lake is an inland body of water that contains significant concentrations of sodium chloride, salt water, and other salinities that exceed the salinity of seawater (3.5%, or 35 grams per liter, or US gallon). 0.29 lbs). Certain microbial species can thrive in high-salinity environments inhospitable to most organisms, including those thought to contribute to the pink lake color. Some of these species go dormant when desiccated, and some are thought to live for over 250 million years. The water in a hypersaline lake is highly buoyant due to its high salinity. Hypersaline lakes are found on all continents, especially in arid regions.
Questions:
- Is there water present on the day of your visit – Yes or No. Now think, does the water or crystals along the water's edge have more Sodium Chloride?
- What is the length of the "lake" at this location? A picture of you and your smartphone/GPS with the lake in the background is required.
- What color are the sodium chloride crystals at this location?
- Look at a few crystals; what shape do they form? (Sodium Chloride will form different shapes depending on the ions they contain) How would you describe the size of the crystals – small, medium, or large?
- Optional: Take a picture of your favorite location in La Sal Del Ray and post the picture with your log entry.
Summary: To claim credit for this EarthCache, you must email your answers to the questions to the cache owner at the time of posting. Additionally, you are encouraged to upload the REQUIRED picture of your favorite place in the park with your log entry. Log entries not accompanied by an email to the cache owner with the answers to the above questions will be deleted.
Sources
Suchan, Jared & Shahid Azam. 2021. Effect of Salinity on Evaporation from Water Surface. Environmental Systems Engineering Faculty of Engineering and Applied Science, University of Regina, 3737 Wascana Parkway, Regina, SK S4S 0A2, Canada
Wallace Hawkins, El Sal del Rey (Austin: Texas State Historical Association, 1947). F. E. Macmanus, La Sal del Rey, or the King's Salt: The Celebrated Texas Salt Lake (Brownsville, Texas, 1885).
Special Thanks to Lower Rio Grande Valley National Wildlife Refuge, U.S. Fish & Wildlife Service for granting permission to publish this Earthcache in La Sal Del Ray.