alkalic


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alkalic

[‚al′kal·ik]
Also known as alkali.
(petrology)
Of igneous rock, containing more than average alkali (K2 O and Na2O) for that clan in which they are found.
Of igneous rock, having feldspathoids or other minerals, such as acmite, so that the molecular ratio of alkali to silica is greater than 1:6.
Of igneous rock, having a low alkali-lime index (51 or less).
References in periodicals archive ?
The combination of new surface mineralization discoveries, lithological orientations, and mapping along the 2.3 km trend are all further evidence for the presence of a 'large' alkalic, silica-undersaturated porphyry with adjacent high-grade skarn system.
Lavas recovered from Bowie seamount range from alkalic basalt and basanite through hawaiite, mugearite and benmoreite (Engel et al.
The suite is clearly alkalic; analyses plot well above the alkalic-tholeiitic boundary.
Verma, "Alkalic (ocean-island basalt type) and calc-alkalic volcanism in the Mexican volcanic belt: a case for plume-related magmatism and propagating rifting at an active margin?" Geology, vol.
The property is situated in the Quesnel Terrane, and the exploration target is an Alkalic copper-gold porphyry deposit.
This specific volcanic formation consists of flows of alkalic olivine basalts similar to the other Pliocene volcanics on Tutuila.
The total P of alkalic post-shield lavas ranges between 0.2 and 1.1% [P.sub.2][O.sub.5] (Clague and Dalrymple 1987).
* High grade Cu-Au lenses typical of alkalic porphyry systems were sampled over a mineralized strike length of 2.7 kilometers at the Eagle Project, including multiple grab samples over 1% Cu and 1 g/t Au.
2) that was assigned the name "litchfieldite" by Bayley (1892), is part of a composite alkalic plutonic complex (Barker 1965) that occupies an area of approximately 7 [km.sup.2] (Fig.