Some scientific results of a mission to South Africa / by Professor Seeley.

  • Seeley, H. G. (Harry Govier), 1839-1909.
Date:
1889
Catalogue details

Licence: Public Domain Mark

Credit: Some scientific results of a mission to South Africa / by Professor Seeley. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    THE TRANSACTIONS OF THE I SOUTH AFRICAN PHILOSOPHICAL SOCIETY. j*. SOME SCIENTIFIC RESULTS OF A MISSION TO SOUTH AFRICA, By Professor Seeley, F.R.S. [Lecture delivered September 16th, 1889.] Your country of South Africa has been heaved up from the sea by a great compressing force, coming from the south, in consequence of which all the older rocks come to the surface of the country towards the southern shores. These older rocks, owing to the intense pressure to which they have been subjected, have become folded, and p heated by conversion of the mechanical pressure into heat ; so that the water, which they originally contained, has slowly, during the long past ages, dissolved a very large part, if not the whole, of the substance ; of the rocks, inconsequence of which these rocks have crystallised and acquired a new texture, totally different from that which they r originally possessed, when laid down as sediments at the bottom of t an ocean. In my survey of the country I have necessarily omitted 1 the most ancient and most altered rocks, which lie upon the extreme I south of the Colony, and my object has been to study the region which'we know as the Great Karoo, and accordingly my attention was > directed in the first place' to the range of mountains which lie to the south of them, and which we know as the Great Zwartberg Range. These rocks I traversed, under the guidance of Mr. Thomas Bain, who made the Zwartberg Pass road, and having gone along the • northern side of the mountains and observed the strongly-inclined ti condition of the top and of the strata, I passed along the southern side ) °f the mountains, and came up in the Oudtsboorn district, by p Schoeman’s Poort, through Meiring’s Poort, which carries the Oli- fant’s River to the southward, and there I saw the wonderful S structure of this range, and admired the rocks, folded in complex i folds, turned up on end, and pointing upward and downward, again f *od again, due south, in thiee grand schemes of contortion ; so that | as the range spreads out, it consists of a comparatively moderate • Sickness of rock, repeated over and over again, owing to the manner