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They were fed by a different magma chamber than Mazama, though they likely received magma from basaltic andesite reservoirs in the vicinity. The exception is Williams crater, which erupted basalt and dacite and got silicic lava from the western part of Mazama's magma chamber. [ 43 ]
A mafic mineral or rock is a silicate mineral or igneous rock rich in magnesium and iron. Most mafic minerals are dark in color, and common rock-forming mafic minerals include olivine, pyroxene, amphibole, and biotite. Common mafic rocks include basalt, diabase and gabbro. Mafic rocks often also contain calcium -rich varieties of plagioclase ...
Because of these mixing mechanisms, lavas may have different compositions but similar appearances, or similar compositions with different appearances. [3] The eruption that produced the Chaos Crags consisted of more than 90% mixed magma, [ 12 ] and likely resulted from the interaction of felsic and mafic magmas.
The two kinds of granitoids have different magma origins: (a) melting of water-rich mafic materials formed older sodium-rich TTG and (b) melting of felsic materials (e.g. TTG and/or sediments [44]) formed younger potassium-rich GMS (see Table 3). [9] [43] They imply gradual chemical changes in the magma and the Earth's crust. [9]
Magma that cools slowly within a magma chamber usually ends up forming bodies of plutonic rocks such as gabbro, diorite and granite, depending upon the composition of the magma. Alternatively, if the magma is erupted it forms volcanic rocks such as basalt , andesite and rhyolite (the extrusive equivalents of gabbro, diorite and granite ...
Calabozos lies between two different types of volcanism—to its north, andesite and rhyolite are the primary constituents of lava while its southern neighbors are composed of more mafic andesite and basalt. It is mainly basaltic andesite and rhyodacite that make up Calabozos, forming a calcalkilic suite rich with potassium.
The tholeiitic magma series (/ ˌθoʊliˈaɪtɪk /) is one of two main magma series in subalkaline igneous rocks, the other being the calc-alkaline series. A magma series is a chemically distinct range of magma compositions that describes the evolution of a mafic magma into a more evolved, silica rich end member. Rock types of the tholeiitic ...
The Lassen volcanic center is fed by two magma chambers, one calc-alkaline reservoir common to the rest of the Cascade Volcanoes, and the other a smaller volume of low-potassium olivine tholeiitic basalt associated with the Basin and Range province. [9] Within the region, most if not all of the volcanic rock has erupted in the past 3 million ...