The formation of the country is a red feldspathic granite, overlaying a decomposing mass of the same rock, forming the soil of all this region, which everywhere is red and gravelly, and appears to be of a great floral fertility.
This is a white feldspathic granite, with small scales of black mica; smoky quartz and garnets appear to constitute this portion of the mountain.
Sienite and feldspar succeeded in our descent to the snow line, where we found a feldspathic granite.
On the south they are smooth, with occasional streaks of pine; but the butte itself is ragged, with escarpments of red feldspathic granite, and dark with pines; the snow reaching from the summit to within a few hundred feet of the trail.
In granitic porphyry that is very poor in quartz, the feldspathicbase is almost granular and laminated.
Feldspathic rocks exhibiting the felsitic texture in whole or in part are known as felsites.
Norite is the most basic of all the feldspathic rocks, as gneiss is the most acidic; while syenite and diorite stand as connecting links, forming a gradual passage between the two extremes.
The name gabbro is sometimes applied to the coarser and more feldspathic diabases, and especially to those containing diallage or hypersthene in the place of common augite.
We turn now to the important and interesting division of the non-feldspathic rocks or schists.
The fundamental rock is everywhere of a pale colour, generally compact, and of a feldspathic nature.
In an adjoining part, I noticed a trap-dike, four feet wide, cut off and covered up by the feldspathic lava, as is represented in Figure 9.
Near Fuentes, I met with pap-formed hills of the compact feldspathic series of rocks.
The lavas of this basal series lie immediately beneath both the basaltic and feldspathic rocks.
On the steep northern slope, I observed in several sections a much worn undulating surface of red tuff, covered by grey, decomposed, feldspathic lavas, with only a thin earthy layer interposed between them.
Its mineralogical constitution is not simple; in some parts the rock is of a cherty, in others of a feldspathic nature, including thin veins of serpentine.
Near the coast the rough lava is quite bare: in the central and higher parts feldspathic rocks by their decomposition have produced a clayey soil, which, where not covered by vegetation, is stained in broad bands of many bright colours.
In the upper portion of these deposits volcanic tuffs or ashy materials are interstratified with ordinary muddy sediment, and here and there associated with thick beds of feldspathic lava.
The name trachyte (from trachus, rough) was originally given to a coarse granular feldspathic rock which was rough and gritty to the touch.
The large quantities of silex in solution required for the formation of these plants may probably arise from the disintegration of feldspathic rocks, which are universally distributed.
The trap-rocks alluded to consist chiefly of feldspathic porphyry and amygdaloid, the kernels of the latter being sometimes calcareous, often chalcedonic, and forming beautiful agates.
The contemporaneous volcanic rocks intercalated in this Upper Old Red consist of feldspathic lavas, or feldstones, with associated tuffs or ashy beds.
This final stage is macroscopically nothing more than a siliceous slate or schist, and is barely distinguishable from the end products of similar metamorphism in the more feldspathic schists and the Loudoun sandy slates.
At many places also gray feldspathic sandstones and basal conglomerates appear.
I have already described the general nature of the rocks in the low country north of Valparaiso, consisting of granites, syenites, greenstones, and altered feldspathic clay-slate.
The dikes are formed of three different varieties of rock, of which a pale brown feldspathic porphyry with grains of quartz was much the most abundant.
Some feldspathic slate, alternating with strata of claystone porphyry in the Bell of Quillota and at Jajuel, and therefore, perhaps, belonging to a later period than the metamorphic schists on the coast, cleaved in this same direction.
Quillota, in some granitic porphyries, in the porphyritic conglomerate, and in the feldspathic clay-slates.
The tufaceous stratum on which this feldspathic lava rests is much hardened, stained purple, and has a spherico-concretionary structure; it here contains a good many pebbles of claystone porphyry.
The white crust, which is commonly seen on weathered feldspathic rocks, does not appear to contain any free carbonate of lime.
However, the English bone porcelains are very beautiful, and though they are not genuine feldspathic products they are highly esteemed and in demand everywhere.
Personally I prefer it to a purefeldspathic china.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "feldspathic" in a variety of sentences. We hope that you will now be able to make sentences using this word.
