WORLD'S WEIRDEST VOLCANO

In Geography today I mentioned some weird lavas in Africa at the Oldoinyo Lengai volcano. 
Do watch the Youtube clip, it is weird!!

https://www.youtube.com/watch?v=qputaVyn7TE

Most volcanologists would agree that the answer to that question is Ol Doinyo Lengai, a volcano in northern Tanzania. From a distance, this handsome volcano doesn't look unusual. The symmetrical cone rises 2,200 m (7,200 ft) above the baking plains of the East African Rift Valley.

During the last century, activity at Ol Doinyo Lengai has been concentrated in its summit crater, which is currently about 400 m across. Because of its remote location, few scientists made the arduous trek to the crater until the last few decades. Those who reach the crater are usually rewarded with the sight of spatter cones, small lava flows, and sometimes lava lakes and low lava fountains. Lava flows have gradually filled the crater, and, in the last two years, thin flows have regularly overflowed the crater rim and descended a short way down the cone.

Intestinal Lava flow

The record that Ol Doinyo Lengai holds is that it is the only volcano in the world known to have erupted carbonatite lava in historical time. Because of its very unusual composition, carbonatite is literally the coolest lava on earth, erupting at 500-600 degrees Centigrade, compared with 1,160 degrees C  for lava from Kilauea's current eruption.

An active carbonatite flow is black or brown and reminds many eyewitnesses of runny mud. Only at night do carbonatite flows glow a dull orange or red.

Freshly cooled flows in the crater of Ol Doinyo Lengai are black but soon turn white because of chemical reactions that occur as the lava absorbs water. In rainy weather, this color change can occur before the flows are cold. Within a few months of erupting, lava flows turn into a brown powder due to water absorption.

What makes this lava so different from the stuff we're used to? The chemical composition of carbonatite magma includes very little silica (silicon dioxide), the most abundant chemical constituent of the earth's crust.

Carbonatite magma at Ol Doinyo Lengai has less than 3% silica and is more akin to something you'd expect to find on a different planet. Cooled carbonatite lava is composed mainly of carbonate minerals. 

NOW FORGET THIS INFORMATION, IT IS NOT ON THE A LEVEL SYLLABUS!!