588 REPORT— 1889. 



I have satisfied myself that Torres Straits is not an area of recent elevation, no 

 traces of raised beaches or of elevated coral formations were observed. The coral 

 beach-rock on Nagir, recorded by Macgillivray, can, I believe, be accounted for 

 without invoking an elevation hypothesis. Depression of land is less easy to 

 demonstrate than elevation, but of this also no evidence could be found. 



Of the volcanic islands, Mer, the largest of the Murray group, was most care- 

 fully studied. Part of the circumference of this island is composed of inclined 

 beds of stratified volcanic ash with a quaquaversal outward dip. In the centre of 

 the island is an old cone. The northerly portion of Mer is mainly a lava stream. 

 Here, again, there are no raised shore or deep-sea deposits. 



2. Report on an Ancient Sea-heach near Bridlington Quay. 

 See Reports, p. 70. 



3. Seventeenth Report on the Erratic Blocks of England, Wales, and 

 Ireland. — See Reports, p. 116. 



4. On a Beep Channel of Drift in the Valley of the Cam, Essex. 

 By W. Whitakek, B.A., F.B.S., F.G.S., Assoc.Bist.C.E. 



Well-sections have given us much information as to the deep-seated geology of 

 the London Basin and of the rising up of older wells beneath the Cretaceous beds. 

 We have now hke evidence of an occurrence of the opposite kind, the deep sinking 

 down of Drift beds. 



In Scotland and in northern England long and deep channels filled with Drift 

 have been noticed, but not in southern England. There are, however, evidences 

 of some such occurrences in Western Norfolk, though not to the depth of the 

 channel now in question. 



For some years one deep well-section has been known which showed a most 

 unexpected thickness of Glacial Drift in the higher part of the \ alley of the Cam, 

 where that Drift occurs mostly on the higher grounds and is of no very great 

 thickness. Lately further evidence has come to hand, showing that the occurrence 

 in question is not confined to one spot, but extends for some miles. Details of this 

 evidence have beeen given in the ' Essex Naturalist,' (vol. iii. pp. 49-54), but the 

 general conclusions are of more than local interest. The beds found are for the 

 most part loamy or clayey. 



At the head of the valley various wells at Quendon and Rickling show irregu- 

 larities in the thickness of the Drift, the Chalk coming to or near the surface in 

 some places, whilst it is nearly 100 feet to it sometimes. 



Further north, at Newport, we have the greatest thickness of Drift hitherto re- 

 corded in the South of England, and then without reaching the base. At one spot 

 a well reached the Chalk at 75 feet, whilst about 150 feet off' that rock crops out,, 

 showing a slope of the chalk-surface of 1 in 2. The most interesting of all the wells- 

 is at the Grammar School, where, after boring to the depth of 340 feet, the work 

 was abandoned without reaching the Chalk, the Drift in this case reaching to a 

 depth of about 140 feet below the level of the sea, though the place is far inland. 

 The Chalk crops out about 100 feet eastward and at but little lower level, so that 

 there is a fall of about 1 in 3 over a long distance. 



At and near Wenden the abrupt way in which Drift comes on against Chalk 

 has been seen in open sections. Two wells have shown a thickness of 210 and of 

 296 feet of Drift respectively, and as the Chalk comes to the surface, at a level 

 certainly not lower, only 140 yards from the latter, the chalk-surface must have a 

 slope of 1 in less than 1|, and this surface must rise again on the other side as the 

 Chalk again crops out. The Drift here reaches to a depth of 60 or 70 feet below 

 the sea-level. 



At Littlebury, still further north, many wells have reached the Chalk at slight 



