GEOLOGICAL FORMATION 155 



from those which are so characteristic of certain 

 portions of the Manica gold mines. These are, for 

 the most part, of a reddish brown, and inclined to 

 be amorphous. 



In some of the stream beds the curious formation 

 known as " pudding-stone " is found. This singular 

 type of rock is said to have been formed by the 

 fluid granite moulding itself in the cooling process 

 upon fragments of dark felspar. 



Between the Muira River and Inyangone, some 

 geological variations occur, isolated patches of 

 hornblende, schist, and gneiss presenting them- 

 selves, whilst, as stated elsewhere, the general rocky 

 system becomes very rugged, especially to the 

 northward of the village of Nkornuam'penembe. 

 1 observed on passing through this district in 1907, 

 considerable evidence of old workings, and was 

 informed that nearly aU the streams contain more 

 or less gold dust in their alluvium. One small 

 stream, I remember, cut through several dykes of 

 apUte as well as of ophitic diabase. More basic 

 dykes appear in this part of the Barud than I 

 observed on any other portion of my journey. 

 From Macor^a, for ten or fifteen miles to the south- 

 ward, the hiUs stiE, generally speaking, preserve 

 their granite formation, but the surrounding region 

 from which they rise might be correctly described, 

 I think, as consisting to some extent of schists 

 crossed by diabase. Thence to the Vunduzi River 

 a slight change takes place in the general aspect. 

 Thus in the stream-beds bands of quartzite appear, 

 striped with iron oxides ; argillaceous chlorite, 

 talc, and mica schists are observable, whilst many 



