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The calc-alkaline magma series is one of two main subdivisions of the subalkaline magma series, the other subalkaline magma series being the tholeiitic series. A magma series is a series of compositions that describes the evolution of a mafic magma, which is high in magnesium and iron and produces basalt or gabbro, as it fractionally crystallizes to become a felsic magma, which is low in ...
Gabbro (/ ˈɡæbroʊ / GAB-roh) is a phaneritic (coarse-grained and magnesium- and iron-rich), mafic intrusive igneous rock formed from the slow cooling magma into a holocrystalline mass deep beneath the Earth 's surface. Slow-cooling, coarse-grained gabbro is chemically equivalent to rapid-cooling, fine-grained basalt.
Compatibility diagrams provide an excellent way to analyze how variations in the rock's composition affect the mineral paragenesis that develops in a rock at particular pressure and temperature conditions. [1] Because of the difficulty of depicting more than three components (as a ternary diagram), usually only the three most important ...
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 ...
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 ...
All alkaline series magmas are thought to have evolved from a primitive mafic alkaline magma, either an alkalic picrite basalt or an ankaramite. This evolves to an alkali olivine basalt or basanite. Thereafter the series branches to the sodic series, the potassic series, or the nephelinic, leucitic, and analcitic series. [1] [2]: Ch6
The magmas that produce ultrapotassic rocks are produced by a variety of mechanisms and from a variety of sources, but generally occur in a heterogenous, anomalous, phlogopite-bearing upper mantle. [2] The following conditions are favorable for the formation of ultrapotassic magmas. [3] partial melting at a great depth; low degrees of partial ...
Model of the crystallization of a subsurface magma chamber. The Skaergaard intrusion was formed 56 million years ago during the opening of the North Atlantic Ocean. [1] The intrusion was emplaced beneath the preexisting rock in the region, including plateau basalt and gneiss. [1][2] The intrusion has a general oval shape, which is atypical in ...