CAMBRIAN ROCKS IN SOUTH SHROPSHIRE.
655
up the difficulty and revealed the true succession. The formations
represented are : — the Shineton Shales ; the Caradoc, consisting of the
Hoar-Edge Grits, the Harnage Shales, and the Chatwall Sandstone ;
and the May-Hill Sandstone, or Upper Llandovery of Murchison.
Fig. 1. — Section through Harnage Grange and Broomcroft.
N.
Harnage Grange.
Broomcroft.
a. May- Hill Sandstone.
b. Chatwall Sandstone.
c. Harnage Shales.
d. Hoar-Edge Grits.
e. Shineton Shale.
In this section the Shineton Shales and the Caradoc are appa-
rently conformable, and dip at an angle of about 15°. The May-
Hill overlies the Caradoc unconformably at a lower angle.
In the road f mile to the west of Harley (see map p. G54)the May-
Hill Sandstone rests immediately upon fossiliferous Shineton Shales,
both dipping at a very low angle. Half a mile to the west of this
locality, a few feet of sandstone with characteristic Caradoc fossils
intervene between the shales and the May-Hill ; and half a mile to
the west of the last locality the section is as above described. Still
further to the west and south-west the Caradoc subformations
thicken out rapidly. The Hoar-Edge Grits especially, which, in the
above section, are represented by sandstone rendered subcalcareous
by fossils, acquire great thickness, and form in some parts massive
beds of grit. They constitute a ridge ranging from above Harnage
Grange, west-south-west, to Shadewell Coppice, where they present
a conspicuous feature in the landscape, the increased elevation
appearing to correspond with the thickening-out of the beds. To
the south-west these beds form the sharp ridge of Hoar Edge. The
dip is about 15° in the above section, but becomes steeper to
the south-west. The strike is east and west in the ridge above
Harnage Grange ; but to the south-west it acquires a south-westerly
trend. The Hoar-Edge Grits are characterized by Strophomena
expansa, Sow., Orthis vespertilio, Sow., and 0. flabellidum, Sow.
The grits are succeeded by the Harnage Shales, which are
hollowed out into a valley parallel to the ridge made by the grits.
The most abundant fossils of these shales, collected near Broomcroft
and in the Harnage and Cound-Brook area, are Trinucletis concen-