582 w. H. PENjS^nfG ON^ thu goldpields of 



Three assays made gave : — 



'No. 1. Quartz, with oxides of iron and manganese, 1 oz. 10 dwt. 

 11 gr. of gold to the ton of 2000 Ih. 

 jSTo. 2. 3 oz. 6 dwt. 16 gr. of gold to the ton of 2000 Ih. 

 No. 3. 9 dwt. 2 gr. of gold to the ton of 2000 lb. 



An open section at Spitzkop shows the upper part, consisting of 

 soft shales, contorted by the irruption of the dyke from below (as in 

 fig. 3), with quartz leaders averaging about six feet apart. Between 

 the shales and the dyke occurs the " rich layer " of black decomposd 

 shale, traversed irregularly in every direction by broken-up veins of 

 quartz. Of this layer, 5 feet thick and conformable to the dyke 

 below, the upper 3 feet are very rich ; it dij)s IST. by. E. into the hill 

 at an angle of 10°. Average samples were taken from this layer by 

 picking down through its whole thickness in several places. The 

 relative proportions by weight were 2^ oz. of decomposed shale and 

 oxide of iron to 1 oz. of quartz. Upon assay, the average sample 

 of the rotten-reef was found to yield 16 dwt. 5 gr. of gold to the 

 ton (2000 lb.). 



Other neighbouring sections of *' rotten-reef," shales, quartz- 

 leaders, and " pay-dirt," are described in the author's B-eport, July 

 1883. " Some shafts are sunk through what appears to be an 

 interstratified mass of decomposed diorite ; if so, it is an intrusion, 

 probably from the main dj'ke, as the shales are seen dipping under 

 it from either side, and disclose beneath it 2 feet of Yeij rich ' pay- 

 dirt.' " One of these shows : — 



3 feet surface-soil. 

 2 „ rich " pay-dirt." 

 6 „ decomposed diorite. 

 16 „ partly decomposed shales with six leaders passed through, 

 the lowest one nearly horizontal. 



A similar belt of rocks occurs from Spitzkop down to the Sabie 

 River, where the fine falls by the roadside are slowly cutting their 

 way back in a mass of sandstone, in which their waters have already 

 formed a ravine many hundred yards in length. Thence to the 

 "Mac Mac diggings" similar rocks prevail, indeed all along the 

 level plateau which borders the low country. 



7c'. The farms " Lisbon " and " Berlyn," formerly called " Water- 

 fall/' are situated on this plateau, and are now being worked by a 

 gold-mining company. The rocks here are shales, occasionally 

 arenaceous ; on the east side are crystalline sandstones, faulted 

 against the shales *. Some of the hills around are capped with 

 chalcedolite. The shales are nearly horizontal, and are intersected 

 at frequent intervals by veins of quartz, varying from 2 to 6 inches 

 in thickness, and dipping at a high angle. These thin veins are 

 auriferous, and appear to be " leaders " from the main quartz-reefs, 

 which run in a nearly N". and S. direction across the property. 

 * See GeoL Mag., April 1885, p. 171. 



