EARLY CONDITION OF THE LAND — ANCIENT LAKES. 549 



On the earliest jluvio -lacustrine deposits of the present surface. 



The Silurian region contains many low flats, so equally and horizontally spread over 

 with fine sand, silt, and flattened shingle, and so surrounded hy hills, as to induce the 

 belief, that they have been occupied by water since the land assumed its present con- 

 figuration. The triangular valley extending from Wigmore to the escarpments of the 

 Ludlow promontory, and called the Wigmore Lake (see p. 238.), is a good example. 

 It is bounded by the hills of Brindgwood Chase on the north, by those of Croft and 

 the Vinnals on the east and south-east, and by Wigmore Rolls upon the west. Only a 

 sluggish rivulet now drains the surplus water and conveys it to the Teme. This river, 

 after meandering in an alluvial flat (Leintwardine bottoms) , connected with the north- 

 western extremity of Wigmore Lake, escapes to the plain of Ludlow through the deep 

 transverse gorge of Downton on the Rock. If this fissure were suddenly dammed up, 

 the waters of the Teme would overflow the whole of the low country, including the 

 triangular space of Wigmore Lake. The fine silt and sand even now adhering to its 

 sides, at Leinthall Starkes and Elton, indicate that water must for a long time have 

 occupied this cavity 1 . In Leintwardine Bottoms we find a top layer of good brown 

 loam, covering sandy and argillaceous earth, and passing downwards into a stiff silt, 

 sometimes containing leaves and sticks, while beneath this and six feet below the sur- 

 face, is a fine gravel of a lacustrine character, and the lowest stratum is a running 

 sand in which water rises. The real subsoil of all this low tract is the Wenlock shale, 

 which, where not covered with the above alluvial sediment, disintegrates to a most 

 unmanageable clay 2 . On first inspecting the physical features of the district it might 

 appear, that ancient currents must have passed from this depression, through the 

 transverse valley in which the river Lugg escapes by Aymestry into the plain of Old 

 Red Sandstone ; the land between Wigmore and Aymestry being encumbered with 

 hillocks of coarse drift, made up of fragments of all the adjacent rocks and deposited 

 at different levels. Now, in all probability the violent operations which upheaved the 

 Ludlow promontory from beneath the sea, and threw it into an anticlinal form, produced 



1 It has before been shown that this valley is one of elevation, and it is also one of denudation, for no loose 

 materials belonging to the rocks which form its sides are to be found within it. Unlike, however, the valleys 

 of Woolhope, p. 436, and of Prescoed, near Usk, p. 441, this hollow is open on one side, namely, the north, 

 west, or the quarter whence the ancient marine drift of this region has been shown to proceed; and hence, 

 as might be expected, a few bowlders and fragments of the rocks of the Caradoc and Longmynd, are to be 

 seen on the face of a rising ground near the centre of the denudation. 



2 To the north-west of Leintwardine, the valley of Clungunford connected with this depression of Wigmore 

 by that of Leintwardine, lies at a higher level, and is filled with much local detritus, sometimes arranged in the 

 following descending order : coarse gravel with bowlders of the adjoining rocks 10 feet; sand 4 feet; clay depth 

 unknown. 



3 z 



