Geological Society of London. 83 



others that of Calcspar. He commented on the dimorphism of carbonate of lime, 

 which mider slightly different conditions assumed different characters ; and re- 

 marked that, as was the case with many igneous rocks, the structure in the Chalk 

 became more apparent after weathering. • 



Mr. Meyer remarked that the striae were most common where nodules were 

 present, and in beds in which the fossils were crushed. So far as he had observed, 

 they were always vertical, and he attributed them to a re-arrangement of the 

 particles of Chalk under pressure. 



The Author explained that two of the specimens had been taken from the sides 

 of a fissure, and were actually slickensides. He thought that some of the nodules 

 exhibit traces of internal structure ; but it was true that the general direction of the 

 striae was at right angles to the lines of bedding. He was glad that his remarks 

 had led to so interesting a discussion. 



The Chairman suggested that an analysis should be made of the specimens. 



2. " A short description of the G-eology of the Eastern. Province 

 of the Colony of the Cape of Good Hope." By R. Pinchin, Esq., 

 C.E. Communicated by H. W. Bristow, F.R:S., F.G.S. 



In this paper, which was illustrated by maps and sections, the 

 author gave the results of his observations on the geology of the 

 above region. The two principal sections described were from Cape 

 Saint Francis across the Grreat Winterhoek and Langeberg ranges to 

 the lacustrine Triassic rocks near Jansenville, and from Port Eliza- 

 beth to Somerset. The lowest rock in the first section is the quartzite 

 of the Great Winterhoek, which is immediately overlain to the 

 northward by clay-shales and sandstones containing Devonian fossils. 

 Beds with similar fossils occur at the Kromme river. Cape St. 

 Francis, and near Uitenhage. A patch of horizontal secondary 

 strata stretches west from the Gamtoos river, overlying the Enon 

 conglomerate in the same way as the Jurassic strata of Uitenhage. 

 They contain no fossils. The Enon conglomerate is seen on the 

 flanks of the higher hills. The northern ranges, Langeberg, Klein 

 Winterhoek, and Zuurbergen, are regarded by the author as formed 

 of rocks belonging to the Carboniferous series, although closely 

 resembling those of the Great Winterhoek in lithological character, 

 except that among them are bands of the peculiar rock described by 

 Bain as "Claystone porphyry," by Wyley as a " Trap conglomerate," 

 by Tate as a "Trap-breccia," and by Atherstone as an "intrusive 

 Trap." Rubidge regarded it as a metamorphic rock ; and this view 

 is adopted by the author, who describes it as underlying and over- 

 lying the clay-shales, which always separate it from the quartzite, 

 and as passing imperceptibly into the clay-shales. The mottled 

 sandstone or Ecca rock is referred by the author to the Carboni- 

 ferous series. The author also noticed the occurrence of Tertiary 

 or recent rocks containing remains of Mollusca identical with 

 species now living in the adjacent seas, lying nnconformably upon 

 the Devonian and conformably upon the Secondary rocks at various 

 places near the coast. 



r)iscussiON. — Prof. Phillips was struck by the manner in which our system and 

 nomenclature was applicable to a country so remote as the Cape. He was inclined 

 to question the metamorphism of the nodules and concretions in the clay-shales 

 into granite, and commented on the supposed interstratification of the metamorphic 

 rocks among unaltered shales. The correlation of the rocks at the Cape with the 

 Devonian and Carboniferous rocks of Europe he thought most interesting, especi- 

 ally taking into account the distance between the two localities. 



