Tuesday, September 16, 2014

Covergence, Prehistoric Lakes, and Salt, oh my!


Photo credit: https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi3HorcXoGI8XZfjaDSqYsHGfBPpf8uBxiLC3oozMnyzj4bV4zUW0gEVFBgu7Iw87J7t8YIQfJZl251ozC3lzul3f9xhAVPhJDUh-NbX50aH0xfbKbscXKZHyfRz2ZFTlIJuC70j3JL77MQ/s1600/Uyuni_Panorama_resize.jpg
The Salar de Uyuni is located in the Andean Altiplano, a high plateau formed by the uplift of the Andean Mountains. The Andean mountains were formed from the convergence of the Nazca oceanic plate with the South American continental plate. Scientists hypothesis that overtime, “parts of the dense lower crust and upper mantle might have periodically detached, which would have allowed the lighter upper crust to rise rapidly”, creating one of the world’s highest plateau in the world (http://earthsky.org/earth/rapid-growth-spurts-formed-vast-and-beautiful-altiplano-plateau). Salar de Uyuni sits in this plateau, at approximately 4,000 miles above sea level and stretches for  3,100 square miles (http://www.eoearth.org/view/article/155833/).
Through radiocarbon dating, the Salar de Uyuni can be traced back to a series of prehistoric lakes. The youngest “palaeolake”, Coipasa, dates back between 11,500 and 13, 400 years ago. And the oldest, Minchin, to about 32,000 years before present. These prehistoric lakes eventually dried up over thousands of years and left behind the great expanse of salt seen today (http://www.nature.com/nature/journal/v409/n6821/full/409698a0.html). This process may have been helped by the uplift of the Altiplano plateau over time, allowing for less runoff as it was enclosed by the surrounding mountains and greater evaporation.

The salt flat is estimated to contain ten billion metric tons of salt. Salt, better known as halite, is a chemical sedimentary rock. But the salt flat is surprisingly made up of more minerals than simply salt, containing contains large amounts of, potassium chloride, lithium cholride and magnesium chloride (http://www.traveltilldie.com/salar-de-uyuni-the-salty-beauty/).

Photo credit: http://intactnature.com/salar-de-uyuni-bolivia



Who knows what other surprises this landscape holds.




Sources:
  • http://earthsky.org/earth/rapid-growth-spurts-formed-vast-and-beautiful-altiplano-plateau




Thursday, August 28, 2014

I am Sylvia Wilson, a senior here at UCD majoring in International Business and minoring in sustainability. I've chosen the salt flats in Bolivia, better known by their Spanish name Salar de Uyuni. The salt flats stretch for miles and miles and are practically devoid of life, except for hundred year old cacti and pink flamingos...can you blame me for being so curious? Take a peak at some of the photos below - this place is visually stunning and very unique, but I would love to dig deeper and find out the reasons behind this incredible phenomenon. I traveled here in the summer of 2012 and at that time never really thought to look at it from a geological perspective. I was just in awe. Hopefully learning about this location through the eyes of a geographer, while incorporating some of my own experiences and photos, will make for a richer understanding! 




Location of the Salar de Uyuni in Bolivia.