The Quarterly journal of the Geological Society of London . e rupturedand destroyed, that it has sustained in a less degree that draggingtowards the surface which has been powerful enough to shatter al-together the bands above it. In the body of the chalk also are gallsor cavities filled with dark-brown clay. These galls are not sectionscutting obliquely across pipes or potholes, which are so commonwhere the chalk or other soft limestone strata have been subjectedto the Postglacial denudation, and into which the bed immediatelyover them commonly descends, but are cavities filled with some ma-t
The Quarterly journal of the Geological Society of London . e rupturedand destroyed, that it has sustained in a less degree that draggingtowards the surface which has been powerful enough to shatter al-together the bands above it. In the body of the chalk also are gallsor cavities filled with dark-brown clay. These galls are not sectionscutting obliquely across pipes or potholes, which are so commonwhere the chalk or other soft limestone strata have been subjectedto the Postglacial denudation, and into which the bed immediatelyover them commonly descends, but are cavities filled with some ma-terial quite foreign to the present superincumbent strata. Pipes, orpotholes, of the well-known kind do, in fact, occur in the adjoiningquarry, and are of great dimensions, passing completely through thethin bed of Lower Drift exposed there, and thence through some 20feet of chalk. These, as is usual in similar cases, are filled with thegravel {d) ; but to them the galls of clay shown in the section haveno relation. Fig. 2.—Section at Litcham a. Chalk with flint bands, becoming gradually more impure upwards, and theflints becoming detached and scattered in the upper part, about 20 feet. red Postglacial gravel. + Grails of dark-brown clay. The lines of shading indicating the chalk in the upper part of the sectionare not to be regarded as lines of stratification. Closely resembling the chalk in this section, are several of the 1866.] HAEMER A THIRD BOULDER-CLAY. 87 transported masses imbedded in the contorted Drift of the Cromercoast, especially that in which the limekiln is worked nnder CromerLighthouse,—galls of dark sand occurring in it there, as those ofclay do here. To what precise action these galls are due, or what the clay isthat fills them, it is difficult to say; but the appearance of the sectionimpresses me strongly with the conviction that we have here evi-dence of the passage of a glacier over the surface of the chalk,—theadhesion of t
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Keywords: ., bookcentury1800, bookdecade1840, bookidquarte, booksubjectgeology
