OF THE EASTEKN PKOVINCE OF CAPE -COLONY. 107 



strips, ultimately either dying out or uniting together again, as the case 

 may be. Their interstratification is shown by, and will be best un- 

 derstood upon reference to, the Section, fig. 2. 



" In no case is this metamorphic rock contiguous to the quartzite, 

 which is itself more or less metamorphosed, but is invariably sepa- 

 rated from it by the clay-shales. It appears underlying and over- 

 lying the clay-shales* in synclinal troughs, in anticlinal axes, in 

 every imaginable position, in and within the clay-shale series ; but it 

 never touches the quartzite. 



" A careful consideration of all of these facts forced the conviction 

 upon my mind that this rock must belong to the clay-shale series, 

 with which it is interstratified, and that it was in all probability 

 metamorphosed since its upheaval and consequent dip. I am the 

 more inclined to this belief, since it is difficult to decide where the 

 one rock ends and the other begins, so imperceptibly do they pass 

 into each other. On the plans and sections (PL IV.) I have drawn 

 a hard line of demarcation between these rocks, for the sake of dis- 

 tinctness ; but no such abrupt line of division occurs in nature." 



Mr. Pinchin expressed his belief that even " the fragments and 

 pebbles of quartz, quartzite, and binary granite " in the great meta- 

 morphic band may have been originally such nodules as are now 

 found in the clay-shales, and that the substance of the latter has 

 been converted into the dolerite-like matrix of the former. 



The mottled beds of " Ecca rock " are referred by the author to the 

 Carboniferous series. The author also referred to the Post-tertiary 

 and recent rocks containing remains of Mollusca identical with spe- 

 cies now living in the adjacent seas, lying unconformably upon the 

 Devonian, and conformably upon the Secondary rocks, at various 

 places near the coast. 



EXPLANATION OF PLATE IV. 



Fig. 1. Geological Map of the Klein Winterhoek and adjacent country, Division 

 of Uitenbage, Cape of Good Hope. 



2. Section along the line AB, in fig. 1. 



3. Plan of the country between Port Elizabeth and Somerset, with Bailey's 



triangulation. 



4. Section from Port Elizabeth to Somerset. 



Discussion. 



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 no- 

 dules and concretions in the clay-shales into granites, and com- 

 mented on the supposed interstratification of metamorphic rocks 

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

 with the Devonian and Carboniferous rocks of Europe he thought 



[* See ' Geologist,' vol. y. 1862, p. 54, figs. 4, 5, 6.— Edit.] 



