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- 

 irieus, P'aton, Beyrichia convplicata, Salt., Primitia bicomis, B. 



