Reviews.
The Geology of the Fenland. By S. B. J. Skertchley, F.G.S.
London: Longmans and Co., 1877, 8vo. Price 40s.
Another Geological Survey Memoir of 335 pages, with some good maps, sections, and woodcuts, but which should have been issued at about half the price mentioned above. The Survey is supported by a Parliamentary grant, its officers receive nothing extra fer the memoirs they write, the publication of which is, indeed, absolutely necessary if the public is to be put in possession of the information which it has a right to expect, and yet this is long delayed, and finally published in a badly got up style and at a high price. contrasting ill with similar publications of other nations, and even with those of our own colonies.
The Fenland embraces an area of about 1,300 square miles, lying round the Wash, and reaching to Wainfleet and Lincoln on the north, Stamford and Peterborough on the west, and Ely and King’s Lynn on the south and east respectively. All this is a low flat country, under which lie the great Oolitic clays—the Kimmeridge and the Oxfordian. But upon these are spread a great thickness of boulder clay, and of gravel, peat, and silt of later date.
Mr. Skertchley has not confined himself to the strictly geological features of his district; he has considered, and rightly so, that the Archæology and the Physical Geography of the region are so closely bound up with the Geology that the one cannot properly be described without the other, and hence his memoir is, perhaps, the most readable which has ever been issued by the Survey. He has carefully studied old documents, and traces the history downwards, from the time of the Romans to that of the present day.
The oldest deposit noticed is the Great Chalky Boulder Clay. This varies from dark to light blue in colour, and is full of striated lumps of chalk; it so contains specimens of basalt, quartzite, coal-measure sandstone, Silurian limestone, slate, flint, &c., in a deep well sunk at Boston in 1828 this deposit was found to be of the enormous thickness of 460 feet. It was here underlain by sands and gravels (Middle Glacial) which were pierced to the depth of 88 feet, while it was overlaid by 21 feet of silt. The author strongly advocates the terrestrial origin of this boulder clay. He believes that it was formed underneath a great glacier, which came pushing down from the northward. In age he would correlate it with the Lower Boulder Clay of Lancashire. At Roslyn Hole, near Ely, a great mass of cretaceous rocks is described, which some Geologists have tried to account for by a complicated system of faults, but which Mr. Skertchley shows to be an enormous boulder, he having seen true boulder clay surrounding and underlying the whole. This transported mass is about 400 yards in length by 60 yards in breadth, and may be compared with the one at Penton, through which the Great Northern line is cut, and with several of similar character in East Leicestershire and Lincolnshire.
