Fog over the Atacama desert was mentioned in a previous post, a connection with water in this the driest desert on earth, were no rain falls year to year, is difficult to fathom. Three million years have passed this land in these conditions. Warm air from the land interacts with the cold Humbolt flowing north off the Chilean coast to condense atmospheric water into micro droplets too light to fall as precipitation, these waft over the desert. Over eons, the ocean minerals dissolved in the micro droplets accumulate
Caliche ore is the result. Different that the hard sedimentary rock in that it is light enough in color to be called “white gold”, the appearance is the same was the following photograph from our visit that same day to ancient geoglphs at Pintados. Look closely to see the geoglphs on the hills (you will have most posts about these later).
Click any photograph for a larger view and use Ctrl-x to zoom in closer.
Ore collection step of the mining operation was to gather the caliche ores off the desert surface, sometimes literally bending down to pick up chunks such as in the photograph. Other times breaking the surface apart with a pick and shovel or a jack hammer, or explosions. In the following photograph is a 1.5 ton ore cart. The cart rim is a little below my shoulder.
The workers, who were from Bolivia (average height 5’3″), Chile (average height 5’7″), and Peru (average height 5’4″), would lift each chunk to chest height then up and over the cart rim……
….to fill the cart. Three mules pull the full carts up a ramp where the gate, at rear of cart is opened, and the ore tumbles down to a railroad wagon (photograph, below). The full wagons are pushed to another ramp where a large rail car is filled and/or the processing site.
We did not visit the processing equipment over at Santa Laura. I recall the guide telling up the enormous machine that ground the caliche ran day and night with a tremendous noise and dust (there are photographs on the World Heritage pages).
Here is a wonderful painting of the entire process from mining to shipping from Iquique.
Wikipedia “Humbolt Current”
Humberstone and Santa Laura Saltpeter Works World Heritage page
Caliche mining: https://www.sqm.com/sqmeninfografias/eng/caliche.html
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