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Where hotspots occur in continental regions, basaltic magma rises through the continental crust, which melts to form rhyolites. These rhyolites can form violent eruptions. [10] [11] For example, the Yellowstone Caldera was formed by some of the most powerful volcanic explosions in geologic history. However, when the rhyolite is completely ...
For example, it is only 28% the size of Earth's Moon and 41% that of Pluto, another dwarf planet. It is comparable in size to Saturn's moons Tethys and Dione . Ceres' small size means that it cooled much faster than full-sized planets and larger moons, limiting its degree of thermal evolution.
Shield volcanoes are large, slow forming volcanoes [6] that erupt fluid basaltic magma that cools to form the extrusive rock basalt. Basalt is composed of minerals readily available in the planet's crust, including feldspars and pyroxenes. [2] Fissure volcanoes pour out low viscosity basaltic magma from fissure vents to form the extrusive rock ...
A volcanic crater is a bowl-shaped depression in the ground caused by volcanic activity, usually located above the volcano's vent. [11] During volcanic eruptions, molten magma and volcanic gases rise from an underground magma chamber, through a conduit, until they reach the crater's vent, from where the gases escape into the atmosphere and the magma is erupted as lava.
Accretionary lapilli form as a result of the cohesive properties of wet ash, causing the particles to bind. They have a circular structure when specimens are viewed in hand and under the microscope. [1] A further control on the morphology and characteristics of a deposit is the water to magma ratio. It is considered that the products of ...
A central-peak crater is the most basic form of complex crater. A central-peak crater can have a tightly spaced, ring-like arrangement of peaks, thus be a peak ring crater, though the peak is often single. [3] Central-peak craters can occur in impact craters via meteorites. An Earthly example is Mistastin crater, in Canada. [1]
"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." A survey of Lake Michigan located at least 40 large craters on the lakebed.
Their rims also can contain variable amounts of local country rock (bedrock) blasted out of their crater. In contrast to tuff cones, the crater of a tuff ring generally has been excavated below the existing ground surface. As a result, water commonly fills a tuff ring's crater to form a lake once eruptions cease. [2] [5]