Rainmaker Mountain
Encyclopedia
Rainmaker Mountain is the name of a mountain located near Pago Pago, American Samoa
on Tutuila Island. The mountain is a volcanic feature known as a trachyte
plug
. This means that it is a volcanic intrusion made of extrusive igneous rock
s having alkali feldspar and minor mafic minerals as the main components and a fine-grained, generally porphyritic
texture. The average annual rainfall on the mountain is around 200 inches (5 m). The mountain is a National Natural Landmark
designated in 1972.
Pago Pago, American Samoa
Pago Pago , also spelled ', is the capital of American Samoa. In 2000, its population was 11,500. The city is served by Pago Pago International Airport. Tourism, entertainment, food, and tuna canning are the primary industries here. From 1878 to 1951, this was a coaling and repair station for the...
on Tutuila Island. The mountain is a volcanic feature known as a trachyte
Trachyte
Trachyte is an igneous volcanic rock with an aphanitic to porphyritic texture. The mineral assemblage consists of essential alkali feldspar; relatively minor plagioclase and quartz or a feldspathoid such as nepheline may also be present....
plug
Volcanic plug
A volcanic plug, also called a volcanic neck or lava neck, is a volcanic landform created when magma hardens within a vent on an active volcano. When forming, a plug can cause an extreme build-up of pressure if volatile-charged magma is trapped beneath it, and this can sometimes lead to an...
. This means that it is a volcanic intrusion made of extrusive igneous rock
Igneous rock
Igneous rock is one of the three main rock types, the others being sedimentary and metamorphic rock. Igneous rock is formed through the cooling and solidification of magma or lava...
s having alkali feldspar and minor mafic minerals as the main components and a fine-grained, generally porphyritic
Porphyry (geology)
Porphyry is a variety of igneous rock consisting of large-grained crystals, such as feldspar or quartz, dispersed in a fine-grained feldspathic matrix or groundmass. The larger crystals are called phenocrysts...
texture. The average annual rainfall on the mountain is around 200 inches (5 m). The mountain is a National Natural Landmark
National Natural Landmark
The National Natural Landmark program recognizes and encourages the conservation of outstanding examples of the natural history of the United States. It is the only natural areas program of national scope that identifies and recognizes the best examples of biological and geological features in...
designated in 1972.