SCHISTS OP THE LIZAED DISTRICT. 6 



mica-schists ; the second by black lustrous hornblende schists, some- 

 times rather massive, sometimes beautifully banded with felspar or 

 epidote ; the third by pinkish-grey quartz-felspar rock closely inter- 

 banded with dark hornblendic or micaceous layers. 



I will commence my description with the southern coast of the 

 Lizard, in which the lowest of these groups is well exposed. In 

 places the cliffs forbid a close examination ; but we are able to de- 

 scend to the sea from time to time so as to obtain a good general 

 idea of the group as a whole. It is, however, difficult from the 

 above cause, from the want of conspicuous characteristics in the 

 different beds, and from the frequency of dislocations*, to establish a 

 very exact succession in the minor subdivisions. At the south-west 

 angle of the Lizard Head, called the Quadrant, we find the following 

 series : — a thick mass of corrugated greenish schist, with " cherty " 

 bands, over which is a quartzose rock of rather gneissic aspect (p. 12) 

 overlain by fissile green schist, whose constituents are so minute as 

 to give it a slaty look. These have a general E.S.E. dip of about 

 25°. At the top of the headland, a little further to the N., is a quartz- 

 ose schist with a slightly steeper dip. I think that these beds are 

 the lowest visible in the series. The coast-line indeed from this 

 point to the serpentine at the south end of Pentreath beach runs 

 nearly N., and S. ; but there is much disturbance, and some discor- 

 dance in the dips. On the whole it is my impression, in accordance 

 with Sir H. De la Beche's views, that we reach higher beds in going 

 northward. At Caerthillian (about a furlong south of the serpentine) 

 the hornblende schist proper is mapped as brought in by a fault. 

 The beds are not in a condition very favourable for examination ; 

 there is undoubtedly a fault beyond which are some hornblendic 

 bands ; but on the whole I am inclined to include all or almost all 

 these beds in the lowest or " tal co-micaceous " group of De la Beche, 

 and think that there is no important dislocation. 



Proceeding eastwards from the Quadrant along the cliffs (which 

 face south), we walk over a series of greenish micaceous schists of 

 rather uniform character, until we descend to the sea at Polpeor, 

 and are able to pass for some little distance at the base of the cliffs. 

 The lowest part of these (well shown in a tiny cove on the west of the 

 little beach) consists of a green epidotic schist in thick bands, alter- 

 nating with brownish very micaceous schist, and with occasional 

 lenticular hornblendic bands, sometimes exhibiting imperfect crystals 

 or "eyes " of whitish felspar, which last rock has a resemblance to the 

 typical hornblende schist of the Lizard district. The general dip is to 

 E.N.E., about 40°. These beds continue to the main cove, being 

 often beautifully corrugated on a small scale, and are exposed in the 

 road descending to the beach. The headland bounding the cove on 

 the east consists of a greenish schist with fairly well-marked folia- 

 tion, but very minute constituents, which becomes at times epidotic. 



* Faults abound in the Lizard district ; they will be noted in almost every 

 cove, inlet, or sea-chasm (of which they are probably the cause). The generally 

 uniform character of the rock makes it extremely difficult to estimate the 

 amount of vertical displacement ; but, as a rule , I believe it to be slight. 



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