﻿26 



PROF. S. H. REYNOLDS OJT THE 



[vol. lxxii,. 



Eastern group of exposures. — The best of these exposures 

 (at the point marked 12 in the map, fig. 1) was somewhat fully- 

 described in 1904. It consists of about 12 feet of red and greenish 

 calcareous tuff dipping at 10° to 15° south-eastwards. Much red 

 calcareous tuff occurs as blocks heaped up in the neighbouring 

 hedge-banks, and the rock is seen in situ at the root of a tree- 

 a short distance north of spot 12, and was exposed at the 

 spot 80 (in the corner of the - next field to the west) by a little- 

 excavation. It was in this field that blocks of fresh olivine-basalt 

 were noticed in 1902, although nothing was found in place. The- 

 basalt, however, occurs here, and was exposed at the point 33 by a 

 little work with the pick. The basalt also extends into the next 

 field to the east, where it forms a somewhat noticeable ridge, and 

 was quickly reached by trenching at the point 101 to the south- 

 east of the pond. This is the last sign of the igneous series in 

 that direction, nothing but limestone occurring on the north and 

 north-west until the western exposure is approached. A broad 

 band of tuff, identical in character with that seen at the point 12, 

 extends in a west-north-westerly direction through the orchard 

 north-west of Goblin Combe Cottage. It was exposed by digging 

 trial-holes at the points 87 and 88, and numerous blocks are to be 

 seen built into the neighbouring walls. The basalt also accompanies 

 the tuff in its extension to the west-north-west ; numerous pieces 

 thrown out by rabbits were to be found in 1914 near the point 87, 

 and the rock was proved by digging at a spot some distance farther- 

 north-west. 



(b) Uphill. 



The exposure here is in a little overgrown quarry opening off 

 from the western side of the railway, about 250 yards north of 

 Bleadon & Uphill Station. The rock is very badly exposed, but at 

 the southern margin of the quarry (see figs. 2 & 3) an amygdaloidal 

 rock is seen resting upon a distinctly uneven surface of cherty 

 limestone. Immediately north and south of this exposure debris 

 and vegetation obscure the relations of the rocks ; but a short 

 distance away to the south a continuous section of limestone is seen^ 

 the beds striking directly at the igneous rock. This is probably 

 explicable by a fault to the south of the igneous exposure ; but if,, 

 as is possible, the rock is intrusive, no fault need be postulated, and 

 the uneven line of junction between trap 1 and limestone is itself 

 suggestive of an intrusion. 



Six excavations were made in the floor of the quarry, and in 

 four of these trap was met with. In the two southernmost 

 (1 and 2), only the base of the trap, which is in a much weathered 

 condition, was exposed, resting on cherty limestone stained red by 

 iron oxide. An excavation (3) at the base of the cliff on the west 

 side of the quarry, showed cherty limestone overlying the trap- 



1 The old term ' trap ' is convenient for use, when one does not wish to pre- 

 judge the question, either as to the nature of the rock, or as to its method of 

 occurrence. 



