Chap. VII.] 
LUDLOW FOEMATION. 
123 
CHAPTER VII. 
UPPEE SILUEIAN EOCKS (continued). 
THE LUDLOW FORMATION, GENERAL CHARACTER OF. ITS SUBDIVISION IN THE TYPICAL DIS- 
TRICTS, INTO LOWER LUDLOW ROCKS, AYMESTRY LIMESTONE, AND UPPER LUDLOW ROCKS. 
In a general sense, the Ludlow rocks of the Silurian region of England 
and "Wales must be simply viewed as a continuation of the argillaceous 
masses which prevail in the underlying Wenlock formation. Such is more 
particularly the case in the lower beds of this deposit. The central por- 
tion, however, in several tracts, particularly at Aymestry, consists of an 
argillaceous dark-grey limestone. The upper member being more sandy 
and somewhat calcareous, yet retaining in parts much of the ' mudstone ' 
matrix, is in great measure an imperfect, thin-bedded, grey-coloured, 
Ludlow Castle. 
(From a Sketch by Lady Harriet Clive, now Baroness Windsor. Sil. Syst. p. 195.) 
In this sketch the Eiver Teme is seen to flow in a chasm of the Upper Ludlow Eocks, 
the strata on which the spectator is supposed to be standing being the same as those 
on which the Castle is built. The basalt of the Titterstone Clee Hill is in the distance, 
surrounded by Old Eed Sandstone, and covered by Carboniferous deposits. 
earthy building-stone. Occasionally the highest stratum is composed of 
light- coloured sandy freestones and tilestones, through which the forma- 
tion graduates lithologically and conformably into the lowest beds of the 
Old Eed or Devonian rocks. 
Such is the general order near the town of Ludlow, which stands upon 
the higher strata of the formation, as shown in this woodcut. Its central 
and inferior masses are best seen either in the escarpments of the adjacent 
hiHs on the S.W., or in that ridge which for a distance of twenty miles on 
the N.E. is interposed between the Wenlock Edge and the Old Eed Sand- 
stone of Corve Dale and the Clee Hills. The section here given will 
