718 



MISS C. A. RAISIN ON THE 



cklorite-sckist to the south ; and over this space several very small 

 springs flow out. The more recent series consists chiefi}- of satiny 

 slates, greenish or greyish, splitting with the characteristic crisp 

 brittle fracture, here and there with hardened bands of impure lime- 

 stone, and cut at places by thick white quartz veins ; they are 

 occasionally contorted and irregular, but for the most part lie smoothly 

 and evenly. The phyllites of the western shore show a steady dip 

 to the west of north ; while the chlorite beds, including micaceous 

 bands, after some variation, set in dipping towards the south. On 

 the eastern bank, the slatj^ beds dip with some exceptions in a 

 southerly direction but the cliffs are so low, and, in cuttings into 

 the phyllite, I so of can noted a tendency for the upper part, even 

 to a depth of four, nve or six feet, to be bent over in an opposite 

 direction to the true dip, that I should hesitate to trust the southerly 

 inclination, if there were not a constant, though interrupted, sug- 

 gestion of it over a space of nearly half a mile. 



5. Eastward of South Pool Estuary. — At Hall Sands there is at 

 first sight some little difficulty in fixing the boundary of the two 

 series ; but on more careful examination, we see that the rocks south 

 of the stream all show schist-like fracturing, and are of very mica- 

 ceous character, onl} T with something of the look of phyllites, due, I 

 doubt not, to subsequent slickensiding or crushing. To the north of 

 the valley the slaty beds have, it is true, a very thorough develop- 

 ment of micaceous surface, and, at places, a wavy lamination, which 

 gives a superficially schistose character, especially when accompanied 

 by corrugations and irregular veinings of quartz ; but these beds are 

 soon interrupted by evenly cleaved true slaty bands. My note made 

 on the spot, after re-examination, was, that " any simulations of phyl- 

 lite, south of Hall Sands, and any simulations of schist, north of 

 Hall Sands, are in each case local and very inextensive ; a small 

 flake of the southern cliffs might be mistaken for phyllite, and a 

 veined fragment of the northern rocks might be thought approxi- 

 mating to schist, but any larger examination, even in the field, would 

 show the distinctness." This conclusion, on referring to Prof. Bon- 

 ney's paper, I found to be in complete agreement with his own 

 summary of the difficulty. 



I walked through most of the lanes lying between South Pool and 

 Hall Sands, and found no difficulty in deciding whether an outcrop 

 was of slaty or of metamorphic rock. Over much of the country the 

 rocks are hidden, but deep cuttings by roadsides and occasional 

 quarries enabled me to decide that the line of fault, traced eastwards, 

 bends rather to the south, running out to the sea at Hall Sands, as 

 marked on Prof. Bonney's map. The boundary runs between the 

 South Pool and Chivelstone valleys, along the summit, or the north- 

 ern slope, of the rising country ; its line is not exactly defined, but 

 I rather incline to mark it somewhere along the more souther^ of 

 its possible positions. Eastwards, to the south of Pord, I found 

 some indications, which suggest the continuation of the fault south 

 of the main road. Yery good exposures mark its position as passing 

 through Killington, to the south of Muckwell, and as having deter- 

 mined the lower part of the course of the Hall-Sands streamlet. 



