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Basalt has a lower total content of alkali oxides than trachybasalt and most basanites and tephrites. [7] Basalt generally has a composition of 45–52 wt% SiO 2, 2–5 wt% total alkalis, [7] 0.5–2.0 wt% TiO 2, 5–14 wt% FeO and 14 wt% or more Al 2 O 3. Contents of CaO are commonly near 10 wt%, those of MgO commonly in the range 5 to 12 wt ...
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 ...
The tholeiitic magma series (/ ˌ θ oʊ l eɪ ˈ ɪ t ɪ k /) 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.
Minerals are distinguished by various chemical and physical properties. Differences in chemical composition and crystal structure distinguish the various species. Within a mineral species there may be variation in physical properties or minor amounts of impurities that are recognized by mineralogists or wider society as a mineral variety.
Volcanic rocks are named according to both their chemical composition and texture. Basalt is a very common volcanic rock with low silica content. Rhyolite is a volcanic rock with high silica content. Rhyolite has silica content similar to that of granite while basalt is compositionally equal to gabbro.
Alkali basalt is one of the rocks comprising the Pali-Aike volcanic field, in Argentina. [1]Alkali basalt or alkali olivine basalt is a dark-colored, porphyritic volcanic rock [2] usually found in oceanic and continental areas associated with volcanic activity, such as oceanic islands, continental rifts and volcanic fields. [3]
The following is a list of rock types recognized by geologists.There is no agreed number of specific types of rock. Any unique combination of chemical composition, mineralogy, grain size, texture, or other distinguishing characteristics can describe a rock type.
Similarly, the range of chemical composition allows chlorite group minerals to exist over a wide range of temperature and pressure conditions. For this reason chlorite minerals are ubiquitous minerals within low and medium temperature metamorphic rocks, some igneous rocks, hydrothermal rocks and deeply buried sediments.