412 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [April 22, 



Geological Survey-map, then passes by Higher Way to the Druid's 

 fault. The want of exposures, however, makes it very difficult to 

 determine whether or not the slates at Alston and Way, which dip 

 towards the Ashburton limestone, may not be Culm-measures 

 brought against it by a fanlt parallel with the turnpike road. The 

 nearly east and west fault which passes E,ew Mill, and which is in 

 part metalliferous, being now worked for copper at the Druids' mine, 

 throws up the underlying Devonian rocks included between it and 

 a nearly parallel fault which ranges from about a quarter of a 

 mile south of Hohie Bridge, past Christophers and Pridhamsleigh, to 

 tlie south of Bulland. These lower rocks thus faulted up dip under 

 the volcanic rocks and limestone of Ashburton ; but about three- 

 quarters of a mile from the town, on the road to Buckland-in-the- 

 iloor, they appear to make a turn over, and become, first vertical 

 and then reversed, at an angle of 65° to the south-east ; and at the 

 Druids' Farm they contain Spirifera disjuncta, Chonetes sorclida,Petraia 

 hina, and CyatJiocrimis pinnatus ? Following these fossiliferous 

 beds along their Hne of strike to the south-west, we find them 

 again in the descent to Holne Bridge, with abundance of Spimfera 

 disjuncta. It would appear, therefore, that these beds are well in 

 the Devonian rocks, and probably not very much below the base of 

 the Ashburton limestone. If we follow them across the Dart, 

 however, we find, just before enteriug Hembury W^ood, that they 

 abut against a mass of thick-bedded grits, with black slates which 

 clearly belong to the Culm-measures. These rocks are highly flexed, 

 and are confined to the east side of the river, where they form a 

 steep ascent of some elevation. On the opposite side of the river 

 the ground is low and consists of slate. Although the two series are 

 not seen in actual contact, it is yet clear that they dip in opposite 

 directions, and that they are brought into apposition by a fault. In 

 all probability this fault runs into the Brook Mill lode south of Hem- 

 bury Castle ; and, in fact, it would appear that the north and south 

 fault we are alluding to is itself metalliferous, as there are the 

 remains of an old copper-mine on the banks of the river. South- 

 ward of the Brook Mill lode, it is impossible to draw the line 

 with any approximation to accuracy, not simply from the want 

 of exposures, but also from the country being covered with frag- 

 ments brought down from the higher ground on the west ; but to 

 the eastward of a line thence by Skeriton we are clearly on the De- 

 vonian rocks*. 



South of Newton BusheU there is a small outlying patch of these 

 Culm-measure grits and slates, which occupies a depression in the 

 Devonian rocks immediately to the east of the limestone of Og- 



* The grits west of Bickington are succeeded by argillaceous slates, which 

 undulate as far as Eamshorn Down, where they pass under the chert-beds of 

 Combe. Now, in some of these beds, Prof. Phillips mentions the occurrence 

 of fossils (Pal. Fos. p. 203) ; but I was not aware of this circumstance until too 

 late, and therefore did not specially examine the locality with a view of ascer- 

 taining the position of these fossiliferous beds ; if, however, they belong to the 

 underlying Devonian series, they must be brought up to the surface either by a 

 sharp anticlinal axis, or by a fault parallel to that of Bickington. 



