phonolites

The volcanic soils of basalts and phonolites, which are more than 3 million years old, are relatively fertile and have been used for plantation crops in the past.

Sao Tome and Principe moist lowland forests 2008

The central bed allows no short cut across: it is a series of rubbish-heaps, parasitic cones, walls, and lumps of red-black lavas, trachytes, and phonolites reposing upon a deluge of frozen volcanic froth ejected by early eruptions.

To the Gold Coast for Gold A Personal Narrative in Two Volumes.—Volume I Richard Francis Burton 1855

What are the affinities which unite the productions of modern volcanoes with the basalts, the phonolites, and those porphyries with bases of feldspar, which are without quartz, and which cover the Cordilleras of Peru and Mexico, as well as the small groups of the Monts Dores, of Cantal, and of Mezen in France?

Travels to the Equinoctial Regions of America 1851

The nature of the phonolites, which are lithoid lavas with a feldspar basis, and the nature of the green slates intermixed with hornblende, oppose this opinion.

Travels to the Equinoctial Regions of America 1851

This regular disposition of lithoid basaltic lava and feldsparry vitreous lava is analogous to the phenomena of all trappean mountains; it reminds us of those phonolites lying in very ancient basalts, those close mixtures of augite and feldspar which cover the hills of wacke or porous amygdaloids: but why are the porphyritic or feldsparry lavas of the Peak found only on the summit of the volcano?

Travels to the Equinoctial Regions of America 1851

I even thought, with many other geologists, that obsidian, so far from being vitrified lava, belonged to rocks that were not volcanic; and that the fire, forcing its way through the basalts, the green-stone rocks, the phonolites, and the porphyries with bases of pitchstone and obsidian, the lavas and pumice-stone were no other than these same rocks altered by the action of the volcanoes.

Travels to the Equinoctial Regions of America 1851

The soil becomes more fertile; the rocky masses alternate with strata of clay, which appear to be produced by the decomposition of the grunsteins, the amygdaloids, and the phonolites.

Travels to the Equinoctial Regions of America 1851

Ortiz, where the amygdaloids and phonolites are connected with the grunstein, everything assumes a basaltic aspect.

Travels to the Equinoctial Regions of America 1851

Cerro de Flores (latitude 9° 28′ to 9° 34′; longitude 70° 2′ to 70° 15′) phonolites and amygdaloids are found on the very border of the basin of the Llanos, that vast inland sea which once filled the whole space between the Cordilleras of Venezuela and Parime.

Travels to the Equinoctial Regions of America 1851

Here, then, is a connexion sufficiently close established between the phonolites and the green slates, between the pyroxenic amygdaloids and the serpentines containing copper-ores, between volcanic substances and others that are included under the vague name of transition-traps.

Travels to the Equinoctial Regions of America 1851