Chap. VIL]
 

LUDLOW FOEMATION.
 

123
 

CHAPTER YII.
 

UPPEE SILUEIAN EOCKS {co7itinued).
 

THE LUDLOW FORMATION, GENERAL  CHARACTER OF.----ITS  SUBDIVISION  IN THE TYPICAL DIS¬
TRICTS, INTO LOWER LUDLOW ROCKS, AYMESTRY LIMESTONE, AND UPPER LUDLOW" ROCKS.

Ix 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
argUlaceous 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. OccasionaUy the highest stratum is composed of
hght-coloured sandy freestones and tUestones, through which the forma¬
tion graduates lithologically and conformably into the lowest beds of the
Old Red 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
hiUs on the S.W., or in that ridge which for a distance of twenty miles on
the X.E. is interposed between the Wenlock Edge and the Old Red Sand¬
stone of Corve Dale and the Clee HiUs.    The section here given wiU