Architectural variety and solidity are favoured in the buildings of the city by a wealth of beautiful building stones of varied colours (limestones, sandstones, lavas, granites and marbles), in addition to which bricks and Roman tiles are employed.
The Barre granites, like those of Woodbury and Calais (also in Washington county) and part of those of South Ryegate, Kirby and Newark (Caledonia county), are of the biotite type; they are grey, except the stone from Newark, which is pinkish.
Of the quartz-monzonite type are the whitish granites of Bethel and Rochester (Windsor county) and Randolph (Orange county), the light grey of Dummerston (Windham county), and the darker greys of Cabot (Washington county), Derby (Orleans county), Hardwick and Groton (Caledonia county) and Topsham (Orange county).
Nelson Dale, The Granites of Vermont (ibid., 1909), an abstract of which appears in the sixth volume of the state Report mentioned above; and Henry M.
In the southern region, which is by far the better known, the oldest rocks are granites, crystalline schists and other rocks of Archean aspect.
28 The granites and dolerites from Magan were too fine and too expensive to build with.
The prevailing formations appear to be granites which are veined with white quartz, and underlie old sedimentary brown sandstone and limestone formations.
-) Gneisses, Schists, Marbles, Granites (Swaziland Series).
- The granites and schists occur in close associa tion.
The plateau is built up of granites, gneisses and crystalline schists of Archean and probably Primary age.
They show a great variety of type made up of slates, quartzites, occasional conglomerates, schists with large masses of intrusive granites and gneiss.
The lower group (Hospital Hill slates) consists of quartzites and shales, resting on the eroded surface of the older granites and schists, and estimated to be from 10,000 to 12,000 ft.
The oldest rocks in the country are the granites, gneisses, &c., of the southern massif and the crystalline schists which form the axis of the Cordillera and the Caribbean chain.
Nelson Dale, The Chief Commercial Granites of Massachusetts, New Hampshire and Rhode Island (Ibid., 1908), being Bulletin 354 of the U.S. Geological Survey.
In this industry, as in the manufacture of cotton goods, Massachusetts has long been without serious rivalry; Brockton, Lynn, The Green Schists and Associated Granites and Porphyries of Rhode Island, Bulletin, U.S. Geological Survey, No.
==Geology== The rocks of the Appalachian belt fall naturally into two divisions; ancient (pre-Cambrian) crystallines, including marbles, schists, gneisses, granites and other massive igneous rocks, and a great succession of Paleozoic sediments.
In the neighbourhood of intrusive granites and similar plutonic igneous rocks, slates undergo "contact alteration," and great changes ensue in their appearance, structure and mineral composition.
The Maryland building stone, of which there is an abundance of good quality, consists chiefly of granites, limestones, slate, marble and sandstones, the greater part of which is quarried in the east section of the Piedmont Plateau especially in Cecil county, though some limestones, including those from which hydraulic cement is manufactured, and some sandstones are obtained from the western part of the Piedmont Plateau and the east section of the Appalachian region; the value of stone quarried in the state in 1907 was $1,439,355, of which $1,183,753 was the value of granite, $142,825 that of limestone, $98,918 that of marble, and $13,859 that of sandstone.
Among the Tertiary volcanic rocks those of acid types (granites, granulites) were the first to appear and are developed latitudinally; rocks of intermediate type (dacites, andesites) characterize the Miocene and early Pliocene periods; while the basic rocks (ophites, elaeolite syenites and basalts) attained their maximum in later Pliocene and Quaternary times.
Granites with an unusually large proportion of soda-lime feldspar), of various grey shades, sometimes tinged with blue, pink or buff, and always marked with black mica; the finer varieties take a high polish and are used for monuments, and the coarser grades are used for construction, especially of railway bridges, and for paving and curbing.
New Hampshire granites were used for building as early as 1623.
The oldest rocks, granites, gneisses and schistose sandstones, the Ngami series, rise to the surface in the east and south-east and doubtless immediately underlie much of the sand areas.
Granites, porphyries and porphyrites belonging to this period occur in the Saxon Erzgebirge, the Harz, Thiiringerwald, Vosges, Brittany, Cornwall and Christiania.
The oldest rocks, forming the greater mass of the hinterland, are gneisses, schists and granites of Archaean age.
Deepand Assuan (First Cataract), the course of the river is interrupted by outcrops of granites and other crystalline rocks, which have been uncovered by the, erosion of the overlying sandstone, and to-day form the mass of islands, with numerous small rapids, which are described not very accurately as cataracts; no good evidence exists in support of the view that they are the remains of a massive barrier, broken down and carried away by some sudden convulsion.
The fundamental rocks of the island are gneisses, through which cut the feldspathic granites which form the Haghier massif.
Through these, again, pierce other granites in dikes or lava flows, and overlying the whole are limestones of Cretaceous and Tertiary age, themselves cut through by later volcanic eruptions.
The central plateau consists of ancient crystalline rocks with granites overlain by unfossiliferous sandstones and conglomerates considered to be of Palaeozoic age.
The median zone is composed largely of crystalline rocks with granites and some Palaeozoic unfossiliferous rocks.
The most ancient of these seem to be the granites of East Finland.
The denudation and destruction of the granites gave rise to the Ladoga schists and various deposits of the same period, which were subsequently strongly folded.
New masses of granites protruded next from underneath, and the Bothnian deposits underwent foldings in their turn, while denudation was again at work on a grand scale.
The tangential pressures which are known to be set up in the earth's crust - either by the contraction of the interior or in some other way - caused the deposits of this sea to be crushed up against the rigid granites and other old rocks of the peninsula and finally led to the whole mass being pushed forward over the edge of the part which did not crumple.
While the general elevation is 7000 to 9000 ft., the individual peaks, consisting largely of granites and metamorphic slates, reach altitudes of 10,000 ft.
The southern parts of the central range are composed of granites, syenites, porphyries and crystalline slates, while in the north of Ichinskaya volcano, which is the highest summit of the peninsula (16,920 ft.), the mountains consist chiefly of Tertiary sandstones and old volcanic rocks.
On the mainland, the north and east shores are of gneisses and granites of archaean age, with a broken and hilly surface rising in places to 600 ft.
Granites and granodiorites were intruded at this period into the older rocks, and altered the adjacent Devonian beds into slates and quartzites, and formed gold-quartz veins, which have been worked in the Devonian rocks at Yalwal.
China clay from the decomposing granites; tin and copper ore, once abounding at the contacts between the granite and the rocks it pierced, were the former staples of wealth, and the mining largely accounts for the exceptional density of population in Cornwall.
We may note the pre-Cambrian lavas and tuffs of the Wrekin district in Shropshire and the somewhat later volcanic rocks of Charnwood; the porphyrites, andesites, tuffs and rhyolites of the Borrowdale volcanic centre, erupted in the Ordovician period, and the Silurian granites of the same region.
The hills of the north-western shore afford a variety of granites and crystalline slates of the Laurentian system, whilst Valamo island is made up of a rock which Russian geologists describe as orthoclastic hypersthenite.
Nelson Dale, The Granites of Maine (Washington, 1907), being Bulletin 313 of the U.
Limestones are by far the most important; red and gray granites, sandstones and marble (Ste Genevieve county) being of little more than local importance.
On the other hand, some rocks in mountain districts, notably the granites, owing to the great quantity of water stored in their numerous fissures or joints, commonly yield a much higher proportion of so-called dry weather flow.
Like the highlands of eastern Asia, those of Turkestan are mostly built up on Pre-Cambrian gneisses and metamorphic slates, resting upon granites, syenites, old orthoclase porphyries, and the like.
Dale, The Chief Commercial Granites of Mass., New Hampshire and Rhode Island (Washington, 1908), Bulletin 354 of the U.S. Geol.
Nelson Dale, The Chief Commercial Granites of Massachusetts, New Hampshire and Rhode Island (Washington, 1908), Bulletin 354 of the U.S. Geological Survey.
These occurrences of granite, with that of Leinster, in connexion with the folding of the Silurian strata, make it highly probable that many of the granites of the Dalradian areas, which have a similar trend and which have invaded the schists so intimately as to form with them a composite gneiss, date also from a post-Silurian epoch of earth-movement.
Certain western and northern granites are however older, since granite boulders occur in Silurian conglomerates derived from the Dalradian complex.
The prevailing types are granites, gneisses and schists.
The earliest signs of igneous activity in Africa are to be found in the granites, intrusive into the older rocks of the Cape peninsula, into those of the Transvaal, and into the gneisses and schists of Central Africa.
The consist of granites, gneisses and mica-schists, with talc-schist5 amphibolites and crystalline himestones.