Reports an^ 'Proceedings — Geological Society of London. 571 



Geological Society of London. 



November 1, 1882.— J. W. Hulke, Esq., F.R.S., President, in the 

 Chair. — The following communications were read : — 



1. "The Hornblendic and other Schists of the Lizard District, 

 with some Additional Notes on the Serpentine." By Prof. T. G. 

 Bonney, M.A., F.E.S., Sec.G.S. 



The author described the metamorphic series, chiefly characterized 

 by hornblendic schist, which occupies the southern portion of the 

 Lizard and an extensive tract to the north of the serpentine region, 

 besides some more limited areas. He found that this series was 

 separable into a lower or micaceous group — schists with various 

 gieen minerals (often a variety of hornblende), or with brownish 

 mica ; a middle or hornblendic group, characterized by black horn- 

 blende ; and an upper or granulitic group, characterized by bands 

 of quartz-felspar rock, often resembling in appearance a vein-granite. 

 These are all highly metamorphosed ; yet the second and third occa- 

 sionally retain to a remarkable extent indications of the minuter 

 bedding structures, siich as alternating lamination and current 

 bedding of various kinds. They form, in the author's opinion, one 

 continuous series, of which the uppermost is the thinnest. The 

 general strike of the series, though there are many variations, is 

 either N.W. or W.N.W. 



The junctions of the Palseozoic with the metamorphic series at 

 Polurrian and at Porthalla were described. These are undoubtedly 

 faulted ; and the two rocks differ greatly, the former being a slate 

 like any ordinary Palaeozoic rock, the other a highlj'^ metamorphosed 

 schist. Moreover, fragments of the hornblende schist and a kind of 

 gneiss occur in a conglomerate in the former, S. of Nare Point. 



The author considers the metamorphic series (the microscopic 

 structure of which was fully described) undoubtedly Archa3an, and 

 probably rather early in that division. The rocks of the micaceous 

 group have considerable resemblance to the greenish and lead- 

 coloured schists of Holyhead Island and the adjoining mainland of 

 Anglesey, and of the Menai Strait. 



Two outlying areas of serpentine, omitted in his former paper, 

 were described — one at Polkerris, the other at Porthalla. The latter 

 shows excellent junctions, and is clearly intrusive in the schist. The 

 author stated that he had re-examined a large part of the district 

 described in his former paj^er, and had obtained additional evidence 

 of the intrusion of the serpentine into the sedimentary rock with 

 which it is associated. This evidence is of so strong a nature that 

 he could not conceive the possibility of any one who would carefully 

 examine the district for himself entertaining a doubt uj)on the 

 matter. 



2. "Notes on some Upper Jurassic Astrorhizidse and Lituolidas." 

 By Dr. Eudolf Hausler, F.G.S. 



The Arenaceous Foraminifera obtained by the author are chiefly 

 from the zones of Ammonites transversarias and A. bimammatus in 



