SCHISTS OP THE LIZARD DISTRICT. 11 



Proceeding southwards, along the foot of the cliffs, the dip of the 

 hornblende schist soon changes to S.W. ; on the south side of a little 

 cove it becomes (being very steep) W.S.W., and on the other side of 

 a jutting headland is even slightly north of west. The rock now 

 exhibits the white spots or " eyes " of felspathic mineral, and, as we 

 rise in the series, shows epidotic bands, and then becomes markedly 

 striped with whitish and blackish layers. By the signal- station on 

 Henscarth the banded hornblende schist (rather contorted) has a 

 high W.N.W. dip (over 70°). In the neighbourhood of Mullion Cove 

 the banded hornblende schist is considerably crumpled * and dis- 

 turbed, and the final dip, where it meets the great mass of serpen- 

 tine on the southern side of the cove, is a high one to E.N.E. This 

 mass of serpentine is probably bounded on both sides by faults ; the 

 hornblende schist, of the ordinary banded type, south of it dips 45° 

 N.E. (in the notch where the streamlet from Higher Pradanack 

 tumbles to the sea), and continues for some time about E.N.E., 

 changing near Pedencrifton to W.S.W. (about 50°). Further south, 

 on Pradanack Point, the schist becomes very massive, in hand speci- 

 mens resembling a diorite, and continues to dip steeply towards 

 the west. On the line of cliffs fronting the south, near Ugethawr, 

 the beds are almost vertical, but incline to the S.W. ; and this general 

 dip continues, becoming less steep and with much local disturbance, 

 till we come to the serpentine at Ugethawr. This rock continues 

 till we again reach the schistose series, as already described, at the 

 south end of Pentreath Beacht. 



It appears, then, as the result of the above observations, that in 



in the " Etage Revinien " of the Ardennes. I have examined microscopically 

 two specimens, one from a micaceous sandy band on the north side of the cove, 

 the other a typical specimen of the slaty rock. The former consists of angular 

 and subangular fragments of quartz imbedded in a minutely granular earthy- 

 looking ground-mass, the result of decomposition of felspathic constituents, 

 with many scales of micaceous minerals ; of these some are colourless, possibly 

 belonging to the hydrous soda or potash group, others are a brown mica ; 

 minute granules of ferrite, opacite, possibly of graphite, abound, and irregular 

 ferrite-stained cracks traverse the slide, roughly following the bedding. The 

 majority of the minerals are clearly of clastic origin, and the amount of meta- 

 morphism is not great. In the phyllite the micaceous and felspathic constituents 

 predominate, but there are still abundant grains of clastic quartz, though more 

 minute ; opacite occurs plentifully with an arrangement somewhat similar to the 

 last, and there are indications of subsequent crumpling. It is less easy to be sure 

 of the origin of the mineral constituents of this rock, owing to their small size ; 

 but I am convinced that though there has probably been a certain subsequent 

 development of sericite and other microliths, all the larger constituents are of 

 clastic origin, and the amount of metamorphism is less than is found in most 

 chiastolites and " spotted " slates. 



* I noted W.N.W., W.S.W., and E.N.E. dips there, which clearly proves 

 rolling : the junction with the serpentine on this "side of the cove " is, I believe, 

 a fault; the copper-mine appears to have been opened in the fault-breccia on the 

 boundary. 



t The small knolls of hornblende schist exposed near Kynance, on the shore, 

 described in my former paper (pp. 888-9), belong to the banded part of the 

 series. I reexamined the singular variety there described, which may possibly 

 indicate a reappearance of the schist in situ, and feel satisfied now that it is 

 not an igneous rock. 



