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Searles Lake and the Trona Pinnacles


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Searles Lake and the Trona Pinnacles

  1. 1. Presentation by Chris Austin Photo by Sandy Redding
  2. 2. Searles Lake is an dry lake bed (playa) in an endorheic basin located southwest of Death Valley and east of Ridgecrest in the Mojave Desert. Click here to view Searles Lake on Google Maps.
  3. 3. An endorheic basin is a terminal or closed basin, having no outflow to another basin or the ocean. Water here can only leave by evaporation. or seepage, thereby leaving salts and other dissolved minerals behind. Click here to learn more about endorheic basins.
  4. 4. Searles Lake was one of the Pleistocene-era lakes, which were fed by massive runoff from the Sierra Nevada mountains. The water spilled into a chain of inland seas. Searles Lake was the third in a chain of five lakes that stretched from Mono Lake to Death Valley and beyond. To learn more about the Pleistocene era, click here.
  5. 5. The lake bed has been commercially mined since John Searles discovered borax here in 1862.
  6. 6. The lake bed is a resource of sodium and potassium minerals, yielding 1.7 million tons of industrial minerals annually, with total mineral reserves exceeding 4 million tons.
  7. 7. The lake bed is also used for evaporative salt extraction . Photo by flickr photographer AlishaV.
  8. 8. The small town of Trona lies on the northwestern side of the lake bed.
  9. 9. The town was established in 1913 as a self-contained company town to house the employees of the local mining operation. Mining is still the main economic activity of the town today.
  10. 10. Soon after the town was built, a branch line was constructed to connect Trona to the Southern Pacific line.
  11. 11. It is still in use today. Photo by Sandy Redding.
  12. 12. The town was named after the mineral trona, which is an evaporite mineral and the primary source of sodium carbonate, also known as soda ash, in the U.S. Soda ash is a key ingredient in many household products, and an important part of many industrial processes. Click here to learn about soda ash.
  13. 13. The mineral extraction process uses a complex solution mining technique that utilizes naturally occurring brines pumped from wells of varying depth beneath the salt pan.
  14. 14. A network of production wells, injection wells, solar ponds and pipes are used to transport the brine to the facilities for processing.
  15. 15. Every year, Trona hosts the Gem-O-Rama show, which draws rockhounds from all over. It is the only time the public is allowed on the lake bed to collect rocks. Find out more about the Gem-O-Rama by clicking here: Photo by flickr photographer AlishaV.
  16. 16. The most interesting feature of the Searles Valley are the Trona Pinnacles located at the south end of the dry lake bed.
  17. 17. The pinnacles are a popular set location. Over 30 film projects a year are shot here, from sci-fi movies to car commercials to TV shows. Photo by T. Hoffarth
  18. 18. Here, more than 500 spires of varying sizes and shapes, some as tall as 140 feet, rise from the dry lake bed.
  19. 19. The site is maintained by the Bureau of Land Management, and is accessible by a 5 mile dirt road located just south of Trona.
  20. 20. The pinnacles are tufa formations which were formed over at least three ice age periods. They are believed to be between 10,000 and 100,000 years old.
  21. 21. Tufa can only be formed underwater, which means these pinnacles were once completely submerged.
  22. 22. Calcium-rich groundwater bubbled up from underwater springs and mixed with the alkaline lake water to create calcium carbonate, the main component of tufa.
  23. 23. The tufa at the Trona Pinnacles is primarily an algal tufa. Algae aided tufa growth by removing carbon dioxide from the water as it photosynthesized, helping the calcium carbonate precipitate.
  24. 24. The shapes of the tufa are dependent upon the size, flow & chemical composition of the hot springs that formed them, as well as the spacing of the springs and the depth of the water at the time they were forming. Click here to learn more about tufa.
  25. 25.  Trona Pinnacles: the Bureau of Land Management website:  Searles Valley Historical Society:  Searles Lake Gem & Mineral Society:  Trona, California: portrait of a mining town:  View Searles Lake and Trona on a Google Map: 56922237476241470.0004920dc8545f957a3cd&ll=35.680725,- 117.319565&spn=0.277759,0.521851&z=11
  26. 26.  The Trona Pinnacles, remembered:  Trona’s Valley Wells, remembered:  How to do the Gem-O-Rama: california.html
  27. 27. Presentation by: Chris Austin Maven’s Manor Photo by Sandy Redding