^56 
GEOGNOSY OF PART OF 
a limestone, and a shale, all liighly inclined. The latter 
rest on a mass of trap (apparently a vein), which termi- 
nates very suddenly. 53 is a highly indurated quartzy 
sandstone ; between it and the basalt are veins of calcare- 
ous spar, pyrites, and heavy-spar. Passing over another 
bed of grit, we come to a trap, which reposes on a shale. 
The next bed of this rock (59) contains large nodules of 
iron-pyrites, very compact quartz, calcareous and pearl 
spar, drusy cavities lined with quartz-crystals, and crystals 
and veins of iroii-glaince, and perhaps of titanium ; and also 
masses of chert or splintery hornston-^, of a bluish-grey 
colour. In this part are also some included portions of 
shale and limestone. 
We afterwards pass a bed of shale and of grit, and then 
the sand prevents any further observations, until we arrive 
at Bamburgh Castle, which is seated on an eminence of 
columnar trap. In the large square tower of this ancient 
building is a Well, supposed to be of Roman v/ork, sunk to 
the depth of 150 feet, 75 feet of which are through trap, 
and the remainder through a freestone. The junction of 
the two beds is visible in several parts of the hill ; they are 
sometimes separated by a thin bed of ruddle or iron-clay. 
The next appearance of any rock is at Iselstone, about 
a mile south of Bamburgh (a reef of rocks so called), 
where, at low-water, appears a large extent of trap, and a 
few yards south of it, a bed of limestone. 
This is the last appearance of this rock to the south for 
several miles, the next being a dike or vein at Beadnell, 
described in the fourth volume of the Transactions of the 
Geological Society. 
The next and only appearance of trap, on the coast north 
of Bamburgh, is at Lindisfarne, or Holy Island, where it 
appears to be part of a dike or vein, probably connected 
"With one which crosses the north load near Kylse, about 
