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Shield volcanoes are found wherever fluid, low- silica lava reaches the surface of a rocky planet. However, they are most characteristic of ocean island volcanism associated with hot spots or with continental rift volcanism. [1] They include the largest active volcanoes on Earth, such as Mauna Loa.
Shield (geology) A shield is a large area of exposed Precambrian crystalline igneous and high-grade metamorphic rocks that form tectonically stable areas. [1] These rocks are older than 570 million years and sometimes date back to around 2 to 3.5 billion years. [citation needed]
The Canadian Shield is a broad region of Precambrian rock (pictured in shades of red) that encircles Hudson Bay. It spans eastern, northeastern, and east-central Canada and the upper midwestern United States. The Canadian Shield (French: Bouclier canadien [buklje kanadjɛ̃]), also called the Laurentian Shield or the Laurentian Plateau, is a ...
The shield volcanoes, for example those in Hawaii, eject magma from the depths of the Earth in zones called hot spots. The lava from these volcanoes is relatively fluid and permits the escape of gases. Composite volcanoes, such as Mount St. Helens and Mount Pinatubo, are associated with tectonic plates.
This list of shield volcanoes includes active, dormant and extinct shield volcanoes. Shield volcanoes are one of the three types [ specify ] of volcanoes. They have a short cone shape, and have basaltic lava which means the lava has low viscosity (viscosity is a measure of the ability for a liquid to flow)
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. The process that forms volcanoes is called volcanism. On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and because most of Earth ...
Kohala (mountain) Kohala is the oldest of five volcanoes that make up the island of Hawaii. Kohala is an estimated one million years old—so old that it experienced, and recorded, the reversal of Earth's magnetic field 780,000 years ago. It is believed to have breached sea level more than 500,000 years ago [1] and to have last erupted 120,000 ...
Olympus Mons is the result of many thousands of highly fluid, basaltic lava flows that poured from volcanic vents over a long period of time (the Hawaiian Islands exemplify similar shield volcanoes on a smaller scale – see Mauna Kea). Like the basalt volcanoes on Earth, Martian basaltic volcanoes are capable of erupting enormous quantities of ...