The olive green syenite found on Mount Ascutney, near the Connecticut river, in Windsor county, is a hornblendeaugite.
Gabbro occurs in the peninsula of Fethland; diorite in Northmavine between Rinas Voe and Mavis Grind; and epidote-syenite in Dunrossness.
Great masses of granite, syenite and diorite were intruded at this period, and send tongues even into the andesitic tuffs.
Geology.'--The Eastern Cordillera., which, however, is but little known, appears to consist, as in Bolivia, chiefly of Palaeozoic rocks; the western ranges of the Andes are formed of Mesozoic beds, together with recent volcanic lavas and ashes; and the lower hills near the coast are composed of granite, syenite and other crystalline rocks, sometimes accompanied by limestones and sandstones, which are probably of Lower Cretaceous age, and often covered by marine Tertiary deposits.
The basis of the islands consist of granite, syenite, diorite, diabase and related kinds of rock, porphyry appearing comparatively seldonr.
The Nahuatl lapidaries had at hand many varieties of workable and beautiful stone - onyx, marble, limestone, quartz and quartz crystal, granite, syenite, basalt, trachyte, rhyolite, diorite and obsidian, the best of material prepared for them by nature; while the Mayas had only limestone, and hard, tenacious rock with which to work it, and timber for burning lime.
Among the rocks of economic importance may be mentioned granite of numerous kinds, syenite, serpentine, porphyry, marble, sandstones and marls.
At Assuan (Syene) the well-known syenite of Werner occurs.
The quarries of Syene (Assuan) are famous for extremely har~ and durable red granite (syenite), and have been worked since the days of the earliest Pharaohs.
Large quantities of this syenite were used in building the Assuan dam (1898-1902).
These are worked in brown basalt, syenite, porphyry, alabaster and limestone.
The materials are quartz crystal, basalt, porphyry, syenite, granite, volcanic ash, various metamorphics, serpentine, slate, dolomite marble, alabaster, many colored marbles, saccharine marble, grey and white limestones.
The most splendid vase is one from Nekhen (Hieraconpolis), of syenite, 2 ft.
The hills are composed principally of granite and syenite, and have little vegetation.
High, "some like gigantic tusks, some like sugar-loaves, and some like vast stalagmites," but all consisting of iron-grey or reddishbrown conglomerate of gneiss, mica-slate, syenite and greenstone.
The oldest rocks consist of gneiss and schist, penetrated by dikes and bosses of granite, syenite, porphyry and other intrusive rocks.
Great masses of syenite and diorite were intruded during the Tertiary period, and within the curve of the folded belt a line of recent volcanic cones stretches from western Baluchistan into eastern Persia.
It consists chiefly of elaeolite-syenite and other rocks derived from the same igneous magma.
A syenite massif of this age occurs at Mittagong; and leucite has been discovered in Carboniferous basalts by David.
The parish is rich in antiquities, but the most noted of them - the Stone of Deer, a sculptured block of syenite, which stood near the Abbey - was destroyed in 1854.
- The ancient or plutonic igneous rocks (including granite, syenite, diorite, gabbro, porphyry, porphyrite, norite retinite) appear at various points of the two previously described regions.
It occurs in regions of granite, porphyry and syenite, and usually occupies funnelshaped cavities of no great superficial area, but of considerable depth.