Where is Lithium Found?
On salt flats usually.
Sometimes in ancient granitic rocks, where it is mined in pits.
Or maybe in clay deposits, where it is also mined in pits, crushed,
washed, and treated.
Salt flat lithium is produced in brine. This liquid is brought to the
surface in water wells, the lithium is extracted from the fluid and
the brine is returned to the reservoir from which it came.
Lithium is abundant, but not concentrated. It has erupted from the
Earth's interior, by way of volcanic outpourings and has been
displaced almost everywhere. Its concentration in the oceans is
about 20 parts per million. Certain types of volcanic rocks are
more enriched than others, particularly the rhyolite variety, which is
abundant on the Tibetan Plateau, parts of outer Mongolia, the high
Andes mountains, and central Nevada.
Below is a Google Earth image of an odd volcanic rock that crops out at
the surface, called a "basaltic tuff". This rock was deposited as
an air-fall deposit that erupted from an explosion about 3 million
years ago that covered several thousand miles of the Earth's surface
near Railroad Valley, Nevada. The chemistry of this basaltic tuff
is unique and it is related to oceanic rocks that were subducted
beneath Nevada. These rocks tunneled upwards from very deep in
the Earth's mantle before erupting. The diagram below the photo
image is a cross section of the rocks, and shows their dip into the
subsurface, their thickness, and associated rocks. It is
super-exciting to touch these rocks!
The great lithium deposits of the world - Atacama, Hombre Muerto,
Zabuye - are concentrations that formed from the
evaporation of lakes into salt flats. Giant lakes, that covered
thousands of square miles and had no outlet, then dried to small
residual ponds of a few tens of miles in size, collecting perhaps 5 or
10 feet of thickness each 25,000 years. This cycle of filling and
evaporation repeated dozens or hundreds of times, forming thick
evaporite sequences of complex salts. Lithium, washed into these
lakes as one of the many salts, is the last to precipitate during
evaporation.