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The Albertine Rift is the western part of the East African Rift. It includes areas of Uganda, the Democratic Republic of the Congo (DRC), Rwanda, Burundi, and Tanzania. It stretches from the northern end of Lake Albert to the southern end of Lake Tanganyika. The term refers to the valley and the mountains around it.

Geology

The Albertine Rift and the surrounding mountains were formed by the slow movement of Earth's plates, which are gradually separating the Somali Plate from the rest of the African continent. The mountains are made of rocks that were pushed up from deep underground, and in some areas, newer volcanic rocks are found on top of these older rocks.

Lakes and rivers

The northern part of the rift is crossed by two large mountain ranges: the Rwenzori Mountains between Lake Albert and Lake Rutanzige (formerly Lake Edward) and the Virunga Mountains between Lake Rutanzige and Lake Kivu. The Virunga Mountains act as a barrier between the Nile Basin to the north and east and the Congo Basin to the west and south. Lake Rutanzige receives water from several large rivers, including the Rutshuru River, and flows north through the Semliki River into Lake Albert. The Victoria Nile flows from Lake Victoria into the northern end of Lake Albert and exits as the White Nile, flowing north toward the Mediterranean.

South of the Virunga Mountains, Lake Kivu flows south into Lake Tanganyika through the Ruzizi River. Lake Tanganyika then flows into the Congo River via the Lukuga River. It is likely that the current water system formed recently when the Virunga volcanoes erupted, blocking the northward flow of water from Lake Kivu into Lake Edward and redirecting it to flow south into Lake Tanganyika. Before this change, Lake Tanganyika, or parts of it, may have had no outlet other than evaporation. The Lukuga River formed recently, allowing aquatic species from the Congo Basin to move into Lake Tanganyika, which previously had different wildlife.

Mountains

From north to south, the mountains include the Lendu Plateau, Rwenzori Mountains, Virunga Mountains, and Itombwe Mountains. The Rwenzori Mountains are named after Ptolemy’s "Mountains of the Moon." This mountain range covers an area 120 km (75 mi) long by 65 km (40 mi) wide. It includes Mount Stanley, which is 5,119 m (16,795 ft) high, Mount Speke at 4,890 m (16,040 ft), and Mount Baker at 4,843 m (15,889 ft). The Virunga Massif, located along the border between Rwanda and the Democratic Republic of the Congo, includes eight volcanoes. Two of these, Nyamuragira and Nyiragongo, are still very active.

Further south, isolated mountain blocks include Mount Bururi in southern Burundi, the Kungwe-Mahale Mountains in western Tanzania, and Mount Kabobo and the Marungu Mountains in the Democratic Republic of the Congo near Lake Tanganyika. Most of these mountain ranges rise to heights between 2,000 m (6,600 ft) and 3,500 m (11,500 ft).

Ecology

The Albertine Rift montane forests are important areas for the environment. Transitional forests, which are between lowland and montane forests, are found at elevations from about 1,000 m (3,300 ft) to 1,750 m (5,740 ft). Montane forests are found on the slopes from about 1,600 m (5,200 ft) to 3,500 m (11,500 ft). Above 2,400 m (7,900 ft), areas of bamboo and elfin forest exist. Heather and grasses are most common above 3,500 m (11,500 ft). The environment is threatened by deforestation because more people need farmland. Illegal logging is another problem, and small-scale gold mining causes some local damage.