shoshonite

shoshonite

[shə′shō‚nīt]
(petrology)
A basaltic rock composed of olivine and augite phenocrysts in a groundmass of labradorite with orthoclase rims, olivine, augite, a small amount of leucite, and some dark-colored glass.
References in periodicals archive ?
22b), samples from the John Lee Brook and Utopia granites plot in the fields of high-K; whereas the sample from the Wellington Lake Granite is associated with the shoshonite series.
The magmatic series of these intrusive bodies are shoshonite and high K calc-alkaline and are of the I type (Ghorbani, 2013).
In order to separate calc-alkaline series with low potassium, average potassium and high potassium and shoshonite ones, [7] diagram is used that is based on K2O quantities in SiO2.
With the western Ibague Batholith characterized by a middle K series signature and the Las Minas Monzodiorite and Altamira Granite showing affinity with the high K series trend (Figure 5d), near the Shoshonite series field.
Shoshonite is an alkali-rich ([Na.sub.2]O + [K.sub.2]O > 6.5 wt %) trachyandesite that occurs in continental rift, collisional and arc settings (Rogers and Setterfield 1994).
The focus of much of this exploration is the Ordovician shoshonite volcanics and related monzonitic intrusions of the central and eastern portions of the Lachlan Fold Belt or Orogen.
1989), samples from the MBG plot in the fields of high-K and shoshonite series, whereas those from the MPG fall into the field of medium K (Fig.
The volcanic rocks of the Nangqen Basin include trachytes, latites, shoshonites, tephrites, tephriphonolites, and phonotephrites that erupted 38.7 Ma ([sup.40]Ar-[sup.39]Ar plagioclase age) [52].
The rocks of the chilled margins and the central facies are classified as tephrites, basalts, basaltic andesites and shoshonites whereas the pegmatoid facies includes the most evolved rocks: andesites and dacites (Fig.
They are clearly different from crustal contaminated, postcollisional Islamic peninsula shoshonites and ultrapotassic rocks.