﻿368 ME. FEEDEEIC P. MENNELL ON THE [Aug. ICjr'd, 



Rivers, They apparently occur also on the south side of the Wankie 

 coal-area, which has, like the previously mentioned coalfield, the 

 structure of a denuded anticline. It remains to be noticed that at 

 the Umkondo Copper-Mine, near the Sabi River, these rocks con-- 

 tain a series of interbedded andesitic lavas. These are more altered 

 than the basalts of the Forest Sandstone period, and their amygdules 

 are often partly filled with epidote, a mineral never seen among 

 those basalts. They are penetrated by dykes of beautifully fresh 

 enstatite-dolerite, and sometimes, like the associated sandstones, 

 contain copper- ore. ! 



(b) The Coal Series. 



As in the case of the underlying rocks, we have little preciser 

 information regarding the coal-beds. Their base and summit have 

 never been defined, and as I am personally acquainted only with 

 the Wankie Coalfield, I shall not attempt to enter into great detail 

 concerning them. As already stated, they appear to be absent from 

 Northern Mashonaland, although at Tete on the Zambezi, in Portu- 

 guese territory, there occur beds from which a strictly Carboniferous 

 flora has been described by Prof. Zeiller. 1 In the south-east of 

 Mashonaland, coal has been discovered about 12 miles south of the 

 Umkondo Copper-Mine, and also close to the junction of the Lundi 

 and Sabi Rivers. The beds also probably extend along the direction 

 of the Limpopo Eiver, though by no means in unbroken continuity, 

 all through the south of the country as far as Tuli. It is in the 

 north of Matabeleland that they exhibit their greatest development, 

 forming the Wankie, Sengwe, Sebungwe, and Mafungabusi coalfields, 

 of which the first-named is at present the only actual coal-producer. 

 Sandstones are always the predominant feature of the series, although 

 shaly beds are generally associated directly with the coal itself. 

 There are, however, conglomerates and occasional concretionary 

 limestones. It appears possible that in the Tuli district the 

 Dwyka (Glacial) Conglomerate is present at the base of the series, 

 as in the Cape Colony and in the Transvaal. It is probable that 

 the rocks include representatives of the Peaufort and Ecca divisions 

 of the ' Karroo System,' although the coal itself may be on a lowe^r 

 horizon than either. As a rule, the coal-bearing series appears to 

 overlie directly the metamorphic rocks or the granite masses, but 

 the beds nearly always emerge from beneath a covering of Forest 

 Sandstone. They occur nowhere at a less distance than 100 miles 

 from the axis of the plateau, and are generally nearer twice that 

 distance, a fact which renders them far less important economically 

 than would be the case if they were nearer the more settled districts. 

 At present, wood is much more extensively used for fuel than coal. 



1 Annates des Mines, ser. 8, vol. iv (1883) pp. 594-98. 



