Vol. 51.] MR. D. DEAPEE ON THE MAEBLE BEDS OF NATAL. 55 



block of marble, detached from the main body, was seen in the 

 granite, together with a small mass of chlorite-schist, similar to that 

 of the Malmesbury Beds of Cape Colony. The small piece of 

 chlorite-schist was all that I could find in the valley, and it is no 

 larger than the block of marble in its vicinity. Both the marble 

 and the schist appear to be surrounded by granite, and project out 

 of the granite-mass. Both are detached blocks. This is the only 

 evidence of the Malmesbury Beds being below the marble ; but, if 

 taken in conjunction with the fact that in no instance could I find 

 any trace of the chlorite-schist (Malmesbury Beds) in the travelled 

 blocks upon the marble in the valley, I think that the evidence is 

 in favour of the marble being younger than the chlorite-schist. 



Evidences of great disturbances of the strata are numerous in the 

 rocks surrounding the valley. The greatest displacement occurs at 

 the junction of the rivers, where a fault, marked x in fig. 1, p. 52, 

 has let down the strata, until the Table-mountain Sandstone, 

 which at one time was no doubt a portion of the plateau (shown in 

 the western extremity of the section), is now 500 feet lower in 

 elevation, and steeply inclined to the east. Again, the northern 

 boundary of the marble is against Table-mountain Sandstone 

 (see fig. 2, p. 54) ; and here evidences of a fault are conspicuous 

 in the abrupt manner in which the two rocks terminate against 

 each other. 



Nowhere could I find evidence of the marble-beds extending 

 under the hills in any direction around the valley. It is certain, 

 however, that the marble does not lie between the Table-mountain 

 Sandstone and the clay-slate ; nor is it connected with any of the 

 newer formations, up to the Ecca Beds. 



That it was deposited before the granite was disturbed is evident 

 by the dip of its beds, indicating that the upheaval of the granite 

 placed them in their present position, as an anticlinal with a syn- 

 clinal on each side of it. I could find no traces of organisms in the 

 marble, nor in the tufaceous limestone. 



Though sections of all the rock-formations from the granite 

 to the Ecca Beds are numerous in the stretch of country lying be- 

 tween Durban and the Umzimkulu, no trace of marble or other 

 limestone, excepting the tufa, has been discovered up to the present 

 time in these parts. 



Judging from the evidence, which I have endeavoured to explain 

 in the foregoing paragraphs, it appears to me : 



1. That the calcareous material from which the marble has been 



formed was deposited upon the granite, and possibly on the 

 Malmesbury Beds, before their disturbance. 



2. That faulting has displaced the beds surrounding the valley. 



3. That the marble is of local occurrence, extending only for a 



limited distance under the surrounding hills. 



4. That its place in the geological sequence is subsequent to the 



deposition of the Malmesbury Beds, and that these latter 

 show no signs of having been extensive here. 



