When you think of lava oozing out of a volcano, you think of the brightness of the hot red liquid. In all the volcano movies, the red liquid burns through everything at an alarming rate. It has no limitation. It runs everywhere like water off of most surfaces. This is the image that everyone gets when they think of a volcano. But dare to imagine a volcano that oozes black lava. Yes, BLACK lava!
Oldoinyo Lengai is a volcano that sits in the Eastern Rift Valley of northern Tanzania, located in east Africa. It stand about 2,886 meters high. Its name, Oldoinyo Lenggai, translates to the Mountain of God in the language of the native people, the Massai. And it is the only active volcano in the East African Rift Valley. It is the “weirdest” volcano known to man. Why? Because it leaks black lava instead of red. Lava is usually red because it is composed of silicates which burn bright red and orange. But this particular volcano has lava made from carbonates instead. Oldoinyo Lengai is the only volcano known to have this very rare characteristics on Earth! It flows out appearing like liquid tar and is not much hotter than asphalt. Which means that this lava is a little over 560 degrees farenheit, according to the Division of Occupational Safety and Health Services Consultation Program of the Washington State Department of Labor and Industries. Usually lava is between 2,000 degrees farenheit according to scholarstic.com. This is a HUGE difference.
Most geologist are baffled by this volcano for its strange trait. Because carbonates are a group of minerals that usually form in the ocean. Oldoinyo Lengai’s lava has close to non silicon in it. Common silicate minerals that are usually found in a common volcano are olivine,pyroxene, and feldspar (all of which we have gone over in class). “On this planet, which is silicates all way down to the iron core, finding an igneous rock without silicon in it is as freaky as taking a water sample from the ocean that has no salt.” Which makes this volcano one of a kind! Scientist can not pinpoint how this came about but they are currently trying to figure out theories as how this volcano came about. “An obvious explanation would be that carbonatite must be some sort of melted limestone, made as a body of magma rises into a buried carbonate deposit, but it isn’t. We know that from the geochemical details, notably high concentrations of rare-earth elements and other constituents, such as niobium, that have no part in true limestone.” SO as you can see, the main theories are being ruled out. Hopefully one day they will be able to explain the phenomenum of black lava!
**All qoutes from: