216 E. HILL AND T. G. BONNEY ON THE 



A specimen of the more compact syenite has been examined from 

 the Sheet-Hedges-Wood pit. A good deal of the slide consists of 

 intercrystallized felspar and quartz, the former rather predominating, 

 with occasional rather large crystals, forming a mosaic of angular 

 pieces, and passing into the graphic state. There is some horn- 

 blende, more or less decomposed, irregular in shape and distribution, 

 with epidote and viridite, as usual. The felspar is considerably de- 

 composed, and occasionally quite replaced by the usual zeolite ; but 

 enough remains to show that both orthoclase and plagioclase are 

 present. There is a fair number of rather small grains of mag- 

 netite and a little apatite. 



Thus these rocks are syenites belonging to the variety rather rich 

 in both quartz and plagioclase felspar, and so somewhat intermediate 

 between typical quartz-syenites, and quartz-diorites. 



(3) Details of the Northern Syenite. — Proceeding now to New-Cliff 

 Plantation, near Garendon Lodge, where two quarries in the north- 

 ernmost patch, marked "Greenstone" on the Survey Map, afford the 

 best opportunity for examining the rock, we find that it chiefly consists 

 of a dull felspathic mineral, of a pale green colour, passing into pale 

 red, and a dark green hornblende. Though at first sight the rock 

 seems very different from that of the southern area, closer examina- 

 tion shows considerable similarity, this being less coarsely crystalline 

 and rather more altered. It passes occasionally into a still more 

 compact rock of a dull green colour. The rock is boldly jointed, with 

 faces weathering of a reddish colour; it is overlain in places by 

 nearly horizontal Keuper. 



We noticed the Longcliff exposure in Part I. (p.788). In general cha- 

 racter it resembles that of Garendon, though perhaps it is a shade more 

 finely crystalline ; and on approaching the sedimentary rock it passes 

 into a very finely crystalline rock of a dull green colour, weathering 

 brownish. A variety at the south end exhibits a slightly foliated 

 structure. The same may be said of the mass of Buck Hill, where 

 the rock also puts on a " greenstone " aspect near the junction with 

 the sedimentary rock. About halfway between the Longcliff and 

 Hammercliff exposures is the Bawdon-Castle patch, which is probably 

 not quite so extensive as it appears in the Survey Map ; though, as 

 the ground is in many places strewn with large boulders, partly 

 buried in the soil, it is often difficult to say whether the rock is or 

 is not in situ. The best exposures are in two copses on the higher 

 ground. In the northern of these the rock, which is fairly well 

 shown in a shallow pit at one end, is, on the whole, rather of the 

 Garendon type, but a little coarser and more decidedly mottled with 

 light red, one specimen which we collected coming very close to a 

 fragment from Hammercliff. In the two fields between this and 

 the next wood are numerous scattered boulders, both of syenite and 

 sedimentary rock. In the latter wood is a most interesting ex- 

 posure. The syenite forms a small steep boss. The heart of this 

 is a rock which, though a little more finely crystalline than the 

 normal Garendon rock, might be matched by specimens from that 

 quarry. In the course of a few yards it passes at its N.N.W. extremity 



