Page:Encyclopædia Britannica, Ninth Edition, v. 10.djvu/710

Rh (588 GLOUC Damory, Charﬁeld, and Woodford is a patch of green- stone, the cause of the upheaval of the Upper Silurian basin of Tortworth, in which are the oldest stratified rocks of the county. Of these the Upper Llandovery is the dominant stratum, exposed near Damory mill, Micklewood chase, and l’urton passage, wrapping round the base of May and Iluutley hills, and reappearing in the vale of Woolhope. The Wenlock limestone is exposed at Falﬁeld mill and Whitﬁeld, and quarried for burning at May hill. The Lower Ludlow shales or mudstones are seen at Berkeley and Purton, where the upper part is probably .-Xymestry limestone. The series of sandy shales and sand- stones which, as Downton sandstones and Ledbury shales, form a transition to the Old Red Sandstone, are quarried at Dymock. The “ Old Red ” itself occurs at Berkeley, 'l‘ort— _ worth Green, T hornbury, and several places in the Bristol coal-ﬁeld, in anticlinal folds forming hills. It forms also the great basin extending from Ross to Monmouth and from Dymock to Mitcheldean, Abenhall, Blakeney, &c., within which is the Carboniferous basin of the Forest. through by the Wye from Monmouth to 'oolaston. This formation is over 8000 feet thick in the Forest of Dean. The Bristol and Forest Carboniferous basins lie within the synclinal folds of the Old Red Sandstone; and though the seams of coal have not yet been correlated, they must have been once continuous, as further appears from the existence of an intermediate basin, recently pierced, under the Severn. The lower limestone shales are 500 feet thick in the Bristol area, and only 165 in the Forest, richly fossiliferous, and famous for their bone bed. The great marine series known as the Mountain Limestone, forming the walls of the grand gorges of the Wye and Avon, are over 2000 feet thick in the latter district, only 480 in the It is cut _ former, where it yields the brown hematite so largely‘. worked for iron even from Roman times. It is much used too for lime and road metal. Above this comes the Mill- stone Grit, well seen at Brandon hill, where it is 1000 feet in thickness, though but 455 in the forest. On this rest the Coal-measures, consisting i11 the Bristol ﬁeld of two great series, the lower 2000 feet thick with 36 seams, the upper 3000 feet with 22 seams, 9 of which reach 2 feet in thickness. These two series are divided by over 1700 feet of hard sandstone (Pennant Grit), containing only 5 coal- seams. In the "Forest coal-ﬁeld the whole series is not 3000 feet thick, with but 15 seams. At Durdham Down a Dolomitic conglomerate, of the age known as Keuper or Upper Trias, rests unconformably on the edges of the Palaeozoic rocks, and is evidently a shore deposit, yielding dinosaurian remains. Above the Keuper clays come the Penarth beds, of which classical sections occur at West- bury, Aust, &c. The series consists of grey marls, black paper shales containing much pyrites and a celebrated bone bed, the Cotham landscape marble, and the white Lias limestone, yielding Oslrea Liassica and Carclimn ]i’/¢a>(i- cum. The district of Over Severn is mainly of Keuper marls. The whole Vale of Gloucester is occupied by the next formation, the Lias, a warm sea deposit of clays and clayey limestones, characterized by ammonites, belemnites, and gigantic saurians. At its base is the insect limestone bed. The pastures producing Gloucester cheese are on the clays of the Lower Lias. The more calcareous Middle Lias or marlstone forms hillocks ﬂanking the Oolite escarpment of the Coteswolds, as at Wotton-under-Edge, and Church- down. The Coteswolds consist of the great limestone series of the Lower Oolite. At the base is a transition series of sands, 30 to 40 feet thick, well developed at Nails- worth and Frocester. Leckhampton hill is a typical section of the Lower Oolite, where the sands are capped by 40 feet of a remarkable pea grit. Above this are 147 feet of free- stone, 7 feet of oolite marl, 3-1 feet of upper freestone, ESTER and 38 feet of ragstone. The Painswick stone belongs to lower freestone. Resting on the Inferior Oolite, and dipping with it to S.l'I., is the “fuller's earth,” a rubbly limestone about 100 feet thick, throwing out many of the springs which form the head waters of the Thames. Next comes the Great or Bath Oolite, at the base of which are the Stonesﬁcld “ slate ” beds, quarried for rooﬁng, paling, &c., at Sevenhampton and elsewhere. From the Great Oolite Minchinhampton stone is obtained, aml at its top is about 40 feet of ﬂaggy Oolite with bands of clay known as the Forest Marble. Ripple marks are abundant on the ﬂags; in fact all the Oolites seem to have been near shore or in shallow water, much of the limestone being merely com- minnted coral. The highest bed of the Lower Oolite is the Cornbrash, about 40 feet of rubble, productive in corn, form- ing a narrow belt fron1 Siddington to Fairford. Near the latter town and Lechlade is a small tract of blue Oxford Clay of the Middle Oolite. The county has no higher Secondary or Tertiary rocks, but the Quaternary series is represented by much northern drift gravel in the Vale and Over Severn, by accumulations of Oolitic detritus, including post-Glacial extinct mammalian remains on the ﬂanks of the Coteswolds, and by submerged forests extending from Sharpness to Gloucester.‘ A_r/rz'cultzn'e.—In the soil of the hill country is so much lin1e that a liberal supply of manure is required. This is provided by folding sheep, and by paring and burning the turf and strewing the ashes on the surface. Good crops of barley and oats are thus obtained, and even of wheat, it‘ the soil is mixed with clay. But the poorest land of the hill country affords excellent pasturage for sheep, the staple commodity of the district; and the sainfoin, which grows wild, yields abundantly under cultivation. The Coteswolds have been famous for the breed of sheep named from them since the early part of the 15th century,—a breed hardy and proliﬁc, with lambs that quickly put on ﬂeece, and become attempered to the bracing cold of the hills, where vegetation is a month later than in the vale. Improved of late years by judicious crossing with the Leicester sheep, the modern Coteswold has attained high perfection of weight, shape, fleece, and quality. The ewes are good mothers; the wool produce, of which the staple is long and mellow to the hand though rather coarse in quality, is an important item, averaging from 7 to 8 lb a head in a Coteswold ﬂock. An impulse has been given to Coteswold farming since the chartering in 1845 of the Royal Agri- cultural College at Cirencester, to instruct young men in farming and the kindred sciences. The pupils engage in the cultivation of a farm of 700 acres attached to the col- lege, aGothicstructure near Circnccster, which has hitherto accommodated on an average 100 inmates. Yet, despite the march of improvement, the aspect of the district is somewhat barren, owing to the absence of trees and hedge- rows in the so-called “stone wall” country, and to the size of the farms, sometimes exceeding 1000 acres. Cattle are kept for home needs and to improve the soil. Oats and barley are the chief grain crops. In the Vale the deep rich black and red loamy soil is well adapted for cattle, and a moist mild climate favours the growth of grasses and root crops. A great proportion of the Yale is in per- manent pasture, and its farmers look largely to hay as the winter food of their stock. The cattle, save on the frontier of Herefordshire, are mostly shorthorns, of which 1 -1uthoritics.——Ge0logy Qf Jfast S'omcrsrt and Gloucester C'oaI:ficMs, II. B. VVoodward, F.G.S.; Jliemoirs of (1001. Survey, London, 1876 ; “Geology of Country round Chcltenham,” E. Hall, A.B., F. G.S., in Jlfemoirs of (leol. Surrey, 1857; “ Geology of Parts of 'ilts and Gloucester," 1'b., 1852; The Chteswold 111113, John Lycett, London, 1857; papers by Mr Lyeett in Quart. Journ. of Geol. Soc., vol. iv., and by Dr Vright in vols. xii. and xvi.