Oldonyo Lengai Mountain
Oldonyo Lengai means "The Mountain of God", in the Maasai language.
It is approximately 150 miles north west of Arusha.
It's elevation is of 2886 meters.
It is the most active volcano in Tanzania, with the last
eruption being in 1983
Ol Doinyo Lengai is a unique and extremely fascinating volcano
that is located about 120 km NW of Arusha, Tanzania. It is the
only volcano in the world that erupts natrocarbonatite lava,
highly fluid lava that contains almost no silicon.
Natrocarbonatite lava is also much cooler than other types of
lava; being only about 950 degrees F (510 degrees C) compared to
temperatures over 2000 degrees F (~1100 degrees C) for basaltic
lava. Natrocarbonatite is the most fluid lava in the world, with
low gas content can flow like a whitewater stream, and actually
has a viscosity near that of water. Natrocarbonatite lava glows
orange at night, but is not nearly as bright as silicon-based
lava since it is not as hot. During the day it is not
incandescent; most flows look like very fluid black oil, or
brown foam, depending on the gas content. In the past, some
visitors to the crater believed they were seeing mud flows. Most
newly solidified lava is black and contains crystals that
sparkle brightly in the sun. There are also small flows known as
"squeeze-ups" that are light gray when they flow and solidify.
Contact with moisture rapidly turns natrocarbonatite lava white
because of chemical reactions that occur when the lava absorbs
water. Eventually the water absorption process turns lava flows
into brown powder. In dry weather the whitening of flows happens
over a period of a few days to a couple of weeks, depending on
the thickness of the flow. In rainy weather the lava surface
turns white immediately. In parts of the crater that have been
inactive for several months, the ground is light brown/white and
so soft that one’s feet sink into it when walking.