Page:VCH Rutland 1.djvu/33

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GEOLOGY THE county of Rutland occupies a portion of the undulating uplands which lie between the great low-lying plain of the Fen- land on the east and the somewhat higher inland plain formed by the outcrop of the Liassic clays on the west. The uplands, which rise in places to 600 and 700 feet above the sea, owe their exis- tence to the outcrop of certain limestones which will be described in the following pages. A sketch map of the geology of Rutland was published by Dr. W. Smith in 1821, but little attention was given to the rocks of this county until they were examined by Professor J. W. Judd for the Geological Survey. His map (engraved on the Ordnance Survey sheet 64) was issued in 1872, and his memoir on 'The Geology of Rutland,' published in 1875, contained a full description of its geological structure as well as a comparison of its rocks with those of more southern coun- ties. It is this map and memoir that form the chief source of our information on the subject. The western border of the county from Belton to Whissendine, coming within the area of sheet 156 of the new series of ordnance maps, receives some notice in the recent official ex- planation of that sheet by Mr. Fox-Strangways entitled, ' The Geology of the Country near Leicester' [Mem. Geol. Survey, 1903). The rocks which come to the surface and form the subsoils of Rut- landshire belong to two very diffisrent series, formed at two widely separ- ate periods of geological time, the Jurassic and the Pleistocene. There are no strata referable to the intervening Cretaceous, Eocene, Oligocene, Miocene and Pliocene periods. Those of the Jurassic rocks which come within the limits of the county belong to the groups known as the Lias and the Lower Oolites, and like most of the formations in this part of England they dip to the eastward, that is to say the beds are not horizontal but are tilted and so inclined that they pass one under the other to the eastward. Conse- quently the older beds are found in the western part of the county and the newer in the eastern part, the latter in their turn passing below the higher Jurassic beds which form the floor of the Fenland. This regular dip of the Jurassic beds is only interrupted here and there by small faults or displacements. The most notable of these faults crosses the valley of the Welland from near Ketton to Duddington, and as it has an upthrow on the eastern side the beds which are brought to the surface on that side are older than those found on the western side.