422 PEOCEEDINGS OF THE GEOLOGICAL SOCIETY. 



Courtenay, and Haldon*. The granite in the district to which this 

 paper relates is for the most part coarse and large-grained, and con- 

 tains a great proportion of schorl, which occurs both disseminated 

 in the rock and in distinct nodules and veins. The schorl varies 

 very much in character, and rubellite has been found near Chag- 

 ford. The examination of fifty-three veins near Chagford showed 

 that thirty-nine ranged in directions from between IN", and E. by N. 

 to between S. and W. by S. No mines are worked on the granite 

 near Chagford ; but several lodes of tin are known to exist there. 

 Veins of porphyry can be seen by the side of the road from Sandy 

 Park to Parford, and near the stack-yard at Eorder near Whiddon 

 Park. 



The Carboniferous beds lying to the north of the Dartmoor gra- 

 nite are broken up by frequent dislocations, and are occasionally 

 contorted; the amount of dip is very variable, the direction being- 

 northerly. The minerals gradually cease as we proceed in an easterly 

 direction ; thus, of the principal minerals there found, it is believed 

 that "lead" and "bismuth" do not exist to the east of Ivy Tor; 

 *' copper," " garnet," and " actinolite " not to the east of Manor 

 Mine at Eamsleigh, and axinite not to the east of a dyke of " fel- 

 spathic trap " near Stone Cross, to the west of Drewsteignton. A 

 vein of manganese was worked to the south of this dyke ; and is also 

 found near the village of Drewsteignton. "With these exceptions, 

 none of the above minerals are known to the east of the dyke, until 

 lead and manganese are again met with in the close vicinity of 

 greenstone dykes, near Christow. Beds of limestone have been 

 worked for many years at South Tawton and Drewsteignton. The 

 only fossil animal remains found are those of the Posidonia, which 

 are met with at South Tawton and Drewsteignton. At Drewsteignton 

 and Dunsford, Calamites and a few other vegetable remains occur. 

 Quartz, felspar, lime, and baryta are found in many various forms 

 along the whole north edge of Dartmoor. The portion of the Car- 

 boniferous beds lying to the north of the granite, to the east of Stone 

 Cross, appears to be free from intruded trap dykes. Veins of granite 

 or elvan occur occasionally in the Carboniferous beds ; at the gorge 

 of the Teign, by Hunt's Tor and Whiddon Park, they are numerous ; 

 and, since the communication of a paper thereon to this Society f, 

 other veins have been found in the same vicinity. The newly dis- 

 covered veins at Hunt's Tor are very extensive; and being at the 

 summit of the Tor a natural horizontal section is seen; in the 18- 

 feet-wide vein at Sharpy Tor a vertical section is exposed; and 

 these two places afford good situations for study. The veins just 

 noticed vary in thickness from a hair's breadth to 18 feet; the elvan 

 or granite in the thin veins is highly crystalline and compact ; the 

 felspar crystals in the central part of the wide veins are large, and 

 diminish in size towards the sides ; distinct crystals of schorl occa- 

 sionally occur, forming small dotted lines in the elvan near the side 

 of the vein, and sometimes crystals of schorl project nearly an inch 



""^ Report of Devon Association for 1862, p. 52. 

 t Quart. Journ. Geol. Soc. vol. xv. p. 191. 



