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THE GEOLOGIST. 



NOTE ON THE GEOLOGY OF SUNDAYS RIVER, 

 SOUTH AFRICA. 



By G. W. Stow, Esq., of Poet Elizabeth. 



A friend and myself undertook a geological excursion a little 

 before Christmas, along the banks of the Sundays River. We 

 started on horseback, and extended our researches some sixty or 

 seventy miles along its banks, examining every kloof and krantz 

 that appeared at all promising. The incidents that befel one on such 

 a trip but add a lively and pleasurable excitement to such an under- 

 taking : now suddenly coming upon a cobra ; anon falling upon the 

 the fresh spoor of a tiger ; finding ourselves fast on the side of a 

 krantz, with the river running some hundred feet immediately below 

 us ; being hooted at by baboons, for invading their solitary realms ; 

 or, lastly, finding the river risen on our return in the evening, and 

 having to make a dash — and swim, splashing through — as best we 

 could on horseback (with nether garments tied around one's neck), to 

 regain our quarters for the night. My friend was very successful, and 

 made a collection of many beautiful fossils. We discovered in some places 

 natural basins, in the hills bordering the river the sides and bottoms 

 of which were literally strewed with scores of magnificent specimens 

 of Trigonia? and Pinna3 broken out entire from the projecting shell- 

 strata, — in fact, being so numerous that it was difficult to know which 

 to select. 



I enclose rough sketches of the Koega Kopjis and of the St. Croix 

 Islands, as they are now seen from this place. They appear so alike 

 in. their conformation — the former isolated quartzite hills rising from 

 the plain, the latter islets some little distance from the mainland — 

 that one is urged to the conclusion that their strata must be equally 

 alike ; and that as the latter are situated now in the present, so must 

 the former have been islands also, in the far more ancient ocean in 

 byegone ages. 



The islands here spoken of I have not visited : but I have been 

 informed by Dr. Rubidge, that they are quartzite also. 



That such was the case, with regard to the Koega Kopjis, is proved 

 most conclusively by the following sketch of an exposed section, on 

 the banks of the Koega River, about three hundred yards from the 

 foot of the hills, on the north side towards the Sundays River. 



Here it will be noticed that the different strata vary most con- 

 siderably in thickness ; and that from five, six, and more feet in 

 thickness, they gradually decrease, as in some of the more central 

 ones, until they are not more than a few inches. It is also very notice- 

 able that the narrower the different bands of strata become, so in 

 proportion their dip increases, — exactly, as it must have been as 



