The geology of soils and substrata, with special reference to agriculture, estates, and sanitation . fell in,leaving on the field an open hole, with perpendicular sides,some feet in depth. This occurred in one of my own fieldswhilst it was being rolled, and the hinder quarters of theshaft-horse fell in ; two or three cart-loads of rubbishwere required to fill up the hole. The subsidence occurredwhere there was a broad depression, as if the surface hadfallen in at several former periods. . The rain-water * H. H. Arnold-Bemrose, Geology in the Field, Gcol. Assoc., 1910> P- K. Tietze, G
The geology of soils and substrata, with special reference to agriculture, estates, and sanitation . fell in,leaving on the field an open hole, with perpendicular sides,some feet in depth. This occurred in one of my own fieldswhilst it was being rolled, and the hinder quarters of theshaft-horse fell in ; two or three cart-loads of rubbishwere required to fill up the hole. The subsidence occurredwhere there was a broad depression, as if the surface hadfallen in at several former periods. . The rain-water * H. H. Arnold-Bemrose, Geology in the Field, Gcol. Assoc., 1910> P- K. Tietze, Geol. Mag., 1874, p. 321. WEATHERING OF ROCKS AND SUBSIDENCES 65 over this whole district sinks perpendicularly into theground, but the chalk is more porous in certain placesthan in others. Thus the drainage from the overlyingclay is directed to certain points, where a greater amountof calcareous matter is dissolved than elsewhere. Evennarrow open channels are sometimes formed in the solidchalk. As the chalk is slowly dissolved over the wholecountry, but more in some parts than in others, the. FIG. 5.—SECTION BY MILL, NORTH OF STOKE HOLY CROSS, , Loamy , Gravel and sand, chalky in places, with a small apparently isolated mass of , Chalk-with-flints, somewhat broken and crumbly in places. Greatest depth seen, 12 feet. undissolved residue—that is, the overlying mass of redclay-with-flints—likewise sinks slowly down, and tends tofill up the pipes or cavities. But the upper part of thered clay holds together, aided probably by the roots ofplants, for a longer time than the lower parts, and thusforms a roof, which sooner or later falls in, as in the above-mentioned five cases. 66 GEOLOGY OF SOILS AND SUBSTRATA A. W. Morant pointed out that when the sewage ofNorwich was conveyed on to the farm at Whitlingham,the land upon which it was discharged was soon coveredwith circular holes, mostly from 3 to 5 feet in diameter,and of various depths ; and on one occas
Size: 1893px × 1320px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectgeology, bookyear1912
