LOCAL DETRITUS IN SHROPSHIRE AND WORCESTERSHIRE. 



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formed by long -continued submarine action ; that the materials occupying their lowest 

 stages can invariably be traced to their parent rocks within very moderate distances ; 

 and lastly, that the purely local detritus is generally covered by clay, sand, and gravel, 

 with bowlders of the northern drift, though the latter are sometimes intermixed with the 

 underlying accumulations of local origin. Similar sections may be seen on the surface 

 of the lias tract between Prees and Whitchurch, where much local detritus is covered 

 by clay and loam containing granite bowlders, the latter lying both on and near the 

 surface, and at small depths in the local gravel. Many more examples might be given, 

 but enough has been stated to show, that the great mass of this local drift underlies the 

 northern. In Worcestershire and in Gloucestershire, the same distinctions can be drawn 

 between local and far transported debris. Large portions of the eastern side of the vales 

 of Gloucester and Worcester are strewed with accumulations of purely local character, 

 derived from the adjacent oolite escarpment, or from the outliers of that system. Near 

 Cheltenham, Evesham and other places, this fine local drift fills depressions in the lias, 

 or is troughed in gullies on the lower slopes of the Cotteswold Hills 1 . Half of the town 

 of Cheltenham is built on such materials, in parts comminuted to a fine sand in 

 which I never observed the fragment of a distant rock. The northern drift is of very 

 different character, and sweeping down the central part of the same valley, it caps, 

 north of Evesham, hills of 300 or 400 feet in height. Below Worcester it composes 

 lower hillocks, derived both from the Oolite on the east and Silurian rocks on the west, 

 mixed up with the finely laminated fragments of northern origin. 



After this description the reader will perceive, that it is not always practicable to 

 separate the more ancient or local drift from the more recent or northern. Nor ought 

 we to find such separations ; for as the materials of the former lined the bottom of the 

 sea when the latter was deposited, there must have been a partial intermixture. Nay, 

 more, if (as I believe) Siluria and the larger part of Wales were dry land, while the 

 country now covered with the northern drift was submerged, the rivers flowing from the 

 former region must have transported fragments of Silurian and other rocks into the 

 same sea in which the granite detritus of the north was accumulated, and in which lived 

 the shells found associated with it. Examples of this intermixture occur specially along 

 or near the borders of ancient Siluria 2 . 



1 I do not mean to assert that the local sandy detritus, near Cheltenham and Evesham, is of the same age 

 as the local drifts of Salop which underlie the northern drift. Some of it may be even younger than the 

 northern drift. Neither Mr. Strickland nor myself have ever detected any organic remains in these local, sandy 

 deposits, which have no distinct relations to the general drift. See " Outlines of the Geology of Cheltenham 

 and neighbourhood." R. I. Murchison. 



2 Much caution is required in distinguishing local from far transported detritus; for what may appear to be- 

 long to the latter can often be strictly referred to the former. Thus, for example, the disintegration of the 

 calcareous conglomerates of the New Red System on the left bank of the Severn, besides pebbles of quartz 

 rock, afford fragments and fossils of the carboniferous limestone ; and as no portion of that rock is in situ, these 

 fragments might be supposed to have been drifted from a great distance, when the alluvial matter was deposited. 



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