62 



LOWER NEW RED, SHROPSHIRE. 



to conglomerate structure'. The other varieties of this rock contain rounded grains of quartz, and 

 white specks, probably of decomposed felspar, with a little iron pyrites, in a calcareous paste, 

 together with bands of coarse-grained pebbly grit and specks of chlorite, in a cement of white cry- 

 stallized carbonate of lime. Some of the calcareous grits enclose concretions of green and red marl, 

 thus resembling the impure cornstones of the Old Red Sandstone. Between Coal Port and Made- 

 ley this sandstone is affected by powerful faults, to the chief of which I shall advert in a sub- 

 sequent chapter ; it being enough for my present purpose to state that along the boundary of this 

 field, as in Staffordshire, great dislocations equally affect the carboniferous strata and the Lower 

 New Red Sandstone 2 . A transverse section from Sturchley to Shifnal, across Nedge Hill, like 

 those previously cited, exposes sandstones and flaggy grits both green and red, and thin courses of 

 slightly calcareous conglomerates and flagstones, associated with much argillaceous marl; the whole 

 passing beneath the younger group of Shifnal, &c. The country around Shifnal, Sheriff Hales, and 

 Crackley Bank, is covered with the quartz pebbles of the disintegrated conglomerate, beneath 

 which a dark- coloured, finely laminated, soft, sandstone is seen at intervals ; but these beds, as 

 well as all those situated midway between Bridgenorth and Wolverhampton, and occupying points 

 intermediate between the coal-fields of Staffordshire and Coal Brook Dale, belong rather to the 

 overlying or great central mass of sandstone. At Lilleshall, the same instructive section, as that 

 from Nedge Hill to Shifnal, is repeated with still greater clearness and fuller development (PI. 29. 

 fig. 15.) In the slopes of the hills below the terrace on which Lilleshall House is built, are stiff, 

 argillaceous beds which produce a cold and unmanageable soil. Other sandy beds, on the contrary, 

 are quite incoherent and very largely micaceous, a rare feature in the supracarbonaceous strata. At 

 Lilleshall Abbey, the lowest strata apparent on the surface are thick-bedded, light brownish sandstones. 

 The junction of these with the underlying coal has never yet been ascertained, but there can exist no 

 doubt of these beingthe true beds of passage into the carboniferous system. Portions of this sandstone 

 are seen at one or two points along the northern flank of the Ketley portion of this coal-field, and they 

 follow the outline of the promontories of the trap and Silurian rocks near Wellington, but are for the 

 most part in an incoherent and decomposed state, and the district is also much obscured by gravel. 

 The lower red sandstone reappears at Wroxeter, Preston Boats 8 , Shrewsbury, and at other places 

 upon the banks of the Severn. (See Map.) It dips away in slightly inclined masses from various 

 small patches of coal at Pitchford and Uffington ; also near Longnor, where the coal-bearing strata of 

 Le Botwood pass gently beneath the red strata of Condover and Stapleton. In that district, 



1 There is a tradition that coal was worked immediately beneath this rock upon the south, and it is in every 

 way probable that such was the case, seeing that the strata dip away from the coal-field of Brosely, on the 

 opposite bank of the Severn. 



2 These are all elaborately described by Mr. J. Prestwich, in whose memoir, preparing for publication in 

 the Geological Transactions, will be found valuable details of the dislocations of the carboniferous and asso- 

 ciated strata in this vicinity. 



3 At Preston Boats the upper part of the old quarries exposes thin-bedded, hard, slightly calcareous beds, 

 with small concretions of dark green impure limestone, closely resembling certain cornstones of the Old Red Sand- 

 stone. In the lower part of the quarry the beds become thicker, and consist of sandstones of deep red colour, 

 with a few blotches of marl. It is from beds of this age, that the Abbey, Castle and many ancient buildings of 

 Shrewsbury have been constructed. Though I have looked in vain for any traces of organic remains in these 

 calcareous beds, we should never despair of such a discovery, when we recollect for how long a period the ex- 

 istence of organic remains was unknown in beds of similar structure in the Old Red Sandstone. (See obser- 

 vations on recently discovered plants and other remains in the New Red Sandstone of Worcestershire, p. 64 note.) 



