Mount Kilimanjaro History
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Mount Kilimanjaro lies on the border of Tanzania and Kenya, just south of the Equator. To the west lies the Great African Rift Valley, created by tremendous tectonic forces which also gave birth to a string of other volcanoes. One of these, Mount Kenya, was originally much higher than Kilimanjaro.
The three summits of Mount Kilimanjaro, Shira, Kibo and Mawenzi are all of very recent origin. Shira and Mawenzi both have suffered considerable erosion and only jagged peaks remain. Kibo, the central, youngest and highest peak has survived as an almost perfect cone.
Although East Africa and nearby Olduvai Gorge is thought to be the cradle of mankind it is unlikely that early man would have been attracted to the steep and cold slopes of Kilimanjaro at a time when it was probably very active and dangerous. A Wachagga legend talks of Mawenzi receiving fire for its pipe from his younger brother Kibo. The Wachagga who live on the fertile volcanic soils around the base of the mountain probably only came to the area about 300 years ago thus this legend suggests very recent activity. Another of their legends talks of demons and evil spirits living on the mountain and guarding immense treasures. Stories are told of a king who decided to go to the top, few of his party survived and those who did had damaged arms and legs.
Arab and Chinese traders and historians make mention of a giant mountain lying inland from Mombasa or Zanzibar but few early traders ventured into the interior of the continent. Slave traders passed below it and sometimes raided the villages of the Wachagga but it was not till the middle of the 19th century that a more serious interest was taken in the mountain and attempts were made to scale it.
In 1848 Johann Rebmann a missionary from Gerlingen in Germany while crossing the plains of Tsavo saw Mount Kilimanjaro. His guide talked of baridi - cold, and of tales how a group of porters were sent up the mountain to bring back the silver or other treasures from the summit.They came back only with water. Rebmann's report stimulated great interest in Germany and in the following years several expeditions were organised; first by Baron von Decken then later by Dr. Hans Meyer who finally stood on the highest point on the 5th of October 1889.
Mount Kilimanjaro, the highest mountain in Africa, now attracts many thousands of walkers each year. On the 1st of January 2000 over 1000 people reached the summit to see the sun rise over a new Millennium.
OLDONYO LENGAI
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Its located just outside the Ngorongoro conservation area to the north east near Lake Natron, Oldonyo
Lengai who's meaning in massai refers to Mountain of God has had major influnce on the development on this area. its ash has blown westwards onto the plains and has helped shaped the landscape and ecology
It is the only active volcano in the area having erupted in 1966, 1982 and recently in 2007
Ol Doinyo Lengai is an active volcano located in the north of Tanzania and is part of the volcanic system of the Great Rift Valley in Eastern Africa. It is located in the eastern Rift Valley, south of both Lake Natron and Kenya. It is unique among active volcanoes in that it produces natrocarbonatite lava, a unique occurrence of volcanic carbonatite. Further, the temperature of its lava as it emerges is only around 510 °C (950 °F). A few older extinct carbonatite volcanoes are located nearby, including Homa Mountain.
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Geology
"Ol Doinyo Lengai" means "The Mountain of God" in the Maasai language of the native people.[3] The record of eruptions on the mountain dates to 1883, and flows were also recorded between 1904 and 1910 and again between 1913 and 1915. A major eruption took place in June 1917, which resulted in volcanic ash being deposited about 48 kilometres away.
A similar eruption took place for several months in 1926 and between July and December 1940, resulting in the ash being deposited as far as Loliondo, which is 100 kilometres away. Several minor eruptions of lava were observed in 1954, 1955, 1958 the early 1960s.
When Ol Doinyo Lengai erupted on August 14, 1966, two geologists — J. B. Dawson and G. C. Clark — who visited the crater a week later, reported seeing “a thick column of black ash” that rose for approximately three thousand feet above the volcano and drifted away northwards towards Lake Natron. When the two climbed the cone-shaped vent, they reported seeing a continuous discharge of gas and whitish-grey ash and dust from the centre of the pit.
Volcanic activity in the mountain caused daily earth tremors in Kenya and Tanzania beginning on July 12, 2007. The latest to hit parts of Nairobi city was recorded on July 18, 2007 at 8.30pm (Kenyan Time). The strongest tremor measured 6.0 on the Richter scale. Geologists suspected that the sudden increase of tremors was indicative of the movement of magma through the Ol Doinyo Lengai. The volcano finally erupted on September 4, 2007, sending a plume of ash and steam at least 18 kilometers downwind and covering the north and west flanks in fresh lava flows. The eruption has continued intermittently into 2008, as of the end of February it was reported that the eruption appeared to be gathering strength, with a major outburst taking place on March 5. During April periods of inactivity have been followed by eruptions on April 8 and 17. Eruptive activity continued until late August 2008. A visit to the summit in September 2008 discovered that lava emission had resumed from two vents in the floor of the new crater. Visits to the crater in March/April 2009 showed that even this activity appears to have ceased.[4]
Lava
Whereas most lavas are rich in silicate minerals, the lava of Ol Doinyo Lengai is a carbonatite. It is rich in the rare sodium and potassium carbonates, nyerereite and gregoryite. Due to this unusual composition, the lava erupts at relatively low temperatures of approximately 500-600 degrees Celsius. This temperature is so low that the molten lava appears black in sunlight, rather than having the red glow common to most lavas. It is also much more fluid than silicate lavas, often less viscous than water. The sodium and potassium carbonate minerals of the lavas formed by Ol Doinyo Lengai are unstable at the Earth's surface and susceptible to rapid weathering, quickly turning from black to grey in color. The resulting volcanic landscape is different from any other in the world.
