of Tor and Babbacombe Bays, Devon. Igg 



pyrites. This may perhaps be an altered limestone. The general character 

 of this mass of trap is the same as that of the small point previously mentioned, 

 being- only more porphyritic and less amygdaloTdal. Good greenstone also 

 occurs. 



At the fault in Oddicombe-sands the trap attains greater elevation, forcing 

 up the shale, and causing it to occupy the top of the cliff. This trap forms 

 the eastern part of the fault to which the Exeter red conglomerate rises^ as if 

 also elevated by it. 



We here learn that the trap was intruded among, and caused disturbance 

 in, the shale and carboniferous limestone after the formation of the Exeter 

 red conglomerate ; for the latter also appears aflected by it. As this conHo- 

 merate contains rounded portions of the limestones and shales, the fault pre- 

 sents two distinct, geological epochs ; one, when the limestones and shales 

 were partially destroyed, aftbrding some of the materials of the conglomerate ; 

 and another, when the trap was intruded among, and disturbed all these 

 strata*. 



A small portion of trap is also seen among the limestones between Babba- 

 combe and the northern head of Anstis Covef. At the bottom of the cove, 

 greenstone, traversed by veins of jasper, is observed among the shale situated 

 between the base of the clilf and the limestones on its summit ; the shales seem 

 disturbed. The greatest mass of trap on the coast constitutes the Black Head 

 near Ilsam];. The principal rock is a greenstone, varying much in grain, and 

 containing iron pyrites ; a very abundant mineral in the trap of this coast. At 

 the base of this head, a thick, arched stratum of limestone is included in the 

 trap. This limestone cannot fail to remind the geologist of those situations 

 where calcareous rocks have become hardened, and rendered more or less 

 crystalline in contact with trappean rocks. The limestones of Ilsam are 

 much disturbed, probably from their vicinity to the Black Head trap. 



No more trap of any importance is found on the north of Tor Bay, and 

 little on the south. Saltern Cove near Goodrington, presents another instance 

 of the limestones and their accompanying shale being altered and disturbed 

 by this rock, which is very compact, fine-grained, and of a mixed greenish 

 and chocolate colour. It sometimes has an arenaceous structure and a reddish 

 tint. Pieces of limestone, much altered, seem in a few instances included in 

 the trap. 



The only remaining trap that I shall here notice, is situated near the high 

 road between King's Kerswell and Dartmouth, not far distant from the con- 



* No pebbles of greenstone are found in this conglomerate, 

 t Plate XVIII. fig. 1. X Plate XVIII. figs. 1. & 2. 



VOL. III. — SECOND SERIES. Z 



