Page:Quarterly Journal of the Geological Society of London, vol. 33.djvu/145

Rh LATER TERTIARY GEOLOGY OE EAST ANGLTA. 107 ft. Upper Glacial clay (5 Coarse gravel 3 Middle Fine gravel, containing shell-fragments and 1 „ Glacial) gradually changing into J (Buff sand 45 Red Crag with shells 6 Red Crag in water 4 Total 67 There was nothing in this deep section answering to the sands described in the first part of this paper as altered Crag, the coarse saccharoid buff-coloured Middle Glacial sand (in the upper part of which occurred the gravel with shell-fragments) being uniform in character throughout its whole thickness, and resting directly on shelly crag. This altered crag occurs, however, in a pit at Seckford Hall, in a small valley about two furlongs from the Well-section. In the before-meutioned " Introduction " we spoke of a brick- earth at Stowmarket, in the valley of the Gipping, as Postglacial ; but Mr. Whitaker informed us that this had been by further exca- vation exposed as passing under the Upper Glacial clay*. Some other exposures of the same deposit occur also in the neighbourhood of the Gipping valley (which is the continuation of that of the Orwell), while on the wide tableland which divides this valley from that of a rivulet flowing into the Little Ouse, a protrusion of the same deposit occurs (as we are informed by Mr. Whitaker) at Woolpit, five miles north-west of Stowmarket. When, some years ago, we examined the many pits at Woolpit, we found one showing the brick-earth over- lying the Upper Glacial, and none showing it beneath that formation ; but we are told that some later excavations do show this, and that therefore brick-earths of two distinct ages, one above and one beneath the Upper Glacial, occur there. These various exposures appear to us to indicate that part of West Suffolk is, like the centre and east of the county, occupied by the Contorted Drift, overspread and concealed by the Upper Glacial, with the Middle Glacial similarly distributed the late Rev. Professor Henslow on a tablet in the Ipswich Museum, the brick - eartb of this brick-field appears to underlie the town, and to possess a thickness equal to that at Kesgrave and Woodbridge. Finding the Middle Glacial in section at the brick-field at a lower level than the section of the brick-earth, we were originally led to regard the latter as over the former, and consequently as Postglacial; but a late visit by one of us to the spot disclosed that the facts are really entirely in harmony with the general features of valley-structure which are discussed in the text, the Middle Glacial, which we had supposed to pass under the brick-earth, only lying against it as a deposit of the interglacial valley cut out of that brick-earth. On the opposite side of the river Gipping the valley-sides are all formed apparently by the Middle and Upper Glacial only, which are in section in the railway-cutting near the Station. The other exposures referred to as occurring in the Gipping valley, are one at Codden- ham Old Hall (where the Contorted Drift is overlain by the Upper Glacial), and the other by Hawk's Mill, on the north side of Needham Market. This last exposure seems to extend up the lateral valley which runs between the two Creetings. In both sections the brick-earth forming this Drift was contorted when we visited them several years ago.
 * From an account of the well sunk at the Stowmarket brewery, given by