Mount Kilimanjaro - Kilimanjaro, Tanzania. Mount Kilimanjaro

Mount Kilimanjaro - Kilimanjaro, Tanzania
Mount Kilimanjaro /ˌkɪlɪmənˈdʒɑːroʊ/,with its three volcanic cones, "Kibo", "Mawenzi", and "Shira", is a dormant volcano in Tanzania. It is the highest mountain in Africa, and rises approximately 4,877 metres (16,001 ft) from its base to 5,895 metres (19,341 ft) above sea level. The first recorded ascent to the summit of the mountain was by Hans Meyer and Ludwig Purtscheller in 1889. The mountain is part of the Kilimanjaro National Park and is a major climbing destination. The mountain has been the subject of many scientific studies because of its shrinking glaciers.
Geology and physical features
Kilimanjaro rises approximately 4,877 metres (16,001 ft) from its southern base in the plains near the municipality of Moshi to its summit height of 5,895 metres (19,341 ft). Kilimanjaro is the highest volcano outside South America.

Kilimanjaro is a large stratovolcano and is composed of three distinct volcanic cones: Kibo, the highest; Mawenzi at 5,149 metres (16,893 ft);and Shira, the shortest at 4,005 metres (13,140 ft).Mawenzi and Shira are extinct, while Kibo is dormant and could erupt again.

Uhuru Peak is the highest summit on Kibo's crater rim. The Tanzania National Parks Authority, a governmental agency,and the United Nations Educational, Scientific and Cultural Organization list the height of Uhuru Peak as 5,895 m (19,341 ft). That height is based on a British Ordnance Survey in 1952.Since then, the height has been measured as 5,892 metres (19,331 ft) in 1999, 5,891 metres (19,327 ft) in 2008, and 5,888 metres (19,318 ft) in 2014.

The interior of the volcanic edifice is poorly known, given the lack of large scale erosion that could have exposed the interiors of the volcano.

Eruptive activity at the Shira centre commenced about 2.5 million years ago, with the last important phase occurring about 1.9 million years ago, just before the northern part of the edifice collapsed. Shira is topped by a broad plateau at 3,800 metres (12,500 ft), which may be a filled caldera. The remnant caldera rim has been degraded deeply by erosion. Before the caldera formed and erosion began, Shira might have been between 16,000 feet (4,900 m) and 17,000 feet (5,200 m) high. It is mostly composed of basic lavas with some pyroclastics. The formation of the caldera was accompanied by lava emanating from ring fractures, but there was no large scale explosive activity. Two cones formed subsequently, the phonolitic one at the northwest end of the ridge and the doleritic "Platzkegel" in the caldera centre.

Both Mawenzi and Kibo began erupting about 1 million years ago. They are separated by the "Saddle Plateau" at 4,400 metres (14,400 ft) elevation.

The youngest dated rocks at Mawenzi are about 448,000 years old. Mawenzi forms a horseshoe shaped ridge with pinnacles and ridges opening to the northeast which has a tower like shape resulting from deep erosion and a mafic dyke swarm. Several large cirques cut into the ring, the largest of these sits on top of the Great Barranco gorge. Also notable are the Ost and West Barrancos on the northeastern side of the mountain. Most of the eastern side of the mountain has been removed by erosion. Mawenzi has a subsidiary peak named Neumann Tower (4,425 metres (14,518 ft)).

Kibo is the largest cone and is more than 15 miles (24 km) wide at the "Saddle Plateau" altitude. The last activity here has been dated to between 150,000 and 200,000 years ago and created the current Kibo summit crater. Kibo still has gas-emitting fumaroles in the crater.Kibo is capped by an almost symmetrical cone with escarpments rising 180 metres (590 ft) to 200 metres (660 ft) on the south side. These escarpments define a 2.5-kilometre-wide (1.6 mi) caldera caused by the collapse of the summit. Within this caldera is the Inner Cone and within the crater of the Inner Cone is the Reusch Crater, which the Tanganyika government in 1954 named after Gustav Otto Richard Reusch upon his climbing the mountain for the 25th time (out of 65 attempts during his lifetime).The Ash Pit, 350 metres (1,150 ft) deep, lies within the Reusch Crater.About 100,000 years ago, part of Kibo's crater rim collapsed, creating the area known as the Western Breach and the Great Barranco.

An almost continuous layer of lavas buries most older geological features, with the exception of exposed strata within the Great West Notch and the Kibo Barranco. The former exposes intrusions of syenite. Kibo has five main lava formations:

phono-tephrites and tephri-phonolites of the "Lava Tower group", on a dyke cropping out at 4,600 metres (15,100 ft), 482,000 years ago