GEOLOGY 



fossils found at Treborough (in west Somerset) and recorded in the 

 second part of his paper, it is quite possible that a detailed survey might 

 justify his views. Stricklandinia lirata and Orthis rustica with some new species 

 including Lingula mortensis were found by him in MuUacot quarry, south 

 of Ilfracombe. The Morte slates pass under the overlying Pickwell 

 Down grits at Foxhunters Inn by the Ilfracombe railway. From the 

 coast, on the south side of the Woolacombe valley, the junction can be 

 easily traced by West Down to the vicinity of Arlington, where it is 

 shifted by a south-easterly fault to Button farm, on the north of Bratton 

 Fleming, and thence runs westward by Office farm to the Somerset 

 boundary at Span Head. An intrusive felsite occurs in the Morte slates, 

 near, or at, their junction with the Pickwell Down grits south of 

 Bittadon,* on the south of Hewish Down, at Smitha Park, Button Wood, 

 and Office farm. 



Upper Devonian.- — The Pickwell Down grits consist of dull purple, 

 red and greenish grits, sandstones, slates and mudstones, and have only 

 yielded ligneous traces. The Baggy beds consist of greenish slates con- 

 taining Lingula, overlain by brown micaceous sandstones and flags 

 containing Gucullaa. 



The Pilton beds consist of grey or dull greenish argillaceous slates, 

 with intercalated beds and masses of brownish grit. They contain 

 lenticles of fossiliferous limestone, now mostly represented by brown 

 friable residua in which an abundant Upper Devonian fauna has been 

 obtained by Professor Phillips, T. M. Hall and subsequent observers. 



The Pickwell Down beds have been taken as the base of the Upper 

 Devonian. At North Molton Ridge a synclinal in this series terminates, 

 carrying the junction of the Pickwell Down and Baggy beds to East 

 Buckland, whence (probably as a fault) it runs by MoUand to Dulverton, 

 crossing the county boundary near East Lipscomb farm. 



The junction of the Pilton beds with the Culm Measures is seldom 

 exposed in section ; through the irregularity of the county boundary 

 this line crosses it in three places, viz. near East Anstey, near Perry (east 

 of Brushford), and finally near Clayhanger. The relations of the Culm 

 and Upper Devonian are frequently faulted between Barnstaple and Clay- 

 hanger. 



CARBONIFEROUS 



As the relations of the Culm rocks, west of a line drawn from 

 Hartland Point to Okehampton and nearly as far south as Tavistock, 

 have never been systematically investigated, the lines on the map are 

 generalized suggestions, especially in the Lower Culm area where Upper 

 Devonian slates and volcanic rocks and Lower and Middle Culm 

 Measures are known to be in plicated and faulted association. The 

 absence of volcanic rocks in the Devonian and Lower Culm Measures of 

 the northern outcrop, and their presence, together with masses of intru- 

 sive greenstone (on either side of Dartmoor, but chiefly on the west), in 



' Bonney, Geol. Mag. 1878, p. 207. 

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