﻿a;v Gneiss 

 i#v (Bornh; 



Fig. 2. 

 dt) Geological 



Map of 

 Nyasaland, 



Karroo. 



■.(Bornhardt) 



Granite 



(Bo'rnhardO 



Gneiss 



(Bornhardt) 



A=Nkana.Area 

 B "K&sant e and 



Lower Rukuru 



Area. 

 C'Mwapo and 



Sere Area. 

 D =Wes tern.Nyika 



Area 



(N.RukuruJ?.) 

 B^Mount Waller 



Area.. 

 F=HengaArea. 

 ^G^Lower Shire 



Area. 



LScale: 1 inch = 



approximately 



85 Miles] 



I Alluvium, etc. 



\Kar.roo System. 



Mafingi Beds. 

 Graphitic Gnei 

 iCrystalline Limestone Series. 



I \Gneiss and Schists. 



\^tiAGranite,Sycnite,etc, often much foliated; 



' N ■= Kepheline-Sodalitc Syenites ofLiwonde& Xyika. 



I ~\Graphitic Gneiss and 



(a) The Crystal- 

 line Series. 



Throughout the 

 greater part of the 

 count ry the crys- 

 talline schists and 

 gneisses have a regu- 

 lar banded appear- 

 ance. As a rule, 

 banding and planes 

 of schistosity agree 

 in direction. 



This stratiform ap- 

 pearance is, in some 

 cases, due to original 

 bedding in a sedi- 

 mentary series, and 

 in others to origi- 

 nal banding in an 

 igneous rock. At 

 times, however, it 

 can be shown to be 

 of secondary origin, 

 induced in homoge- 

 neous igneous rocks 

 by local crushing. 

 Quartz - reefs also 

 crossing plutonic 

 masses have occa- 

 sionally been so 

 crushed and granu- 

 lated as to simulate 

 altered sedimentary 

 rocks. 



To rocks of un- 

 doubted sedimentary 

 origin, however, be- 

 long the quartzitic 

 and micaceous schists 

 of the Nyika and the 

 quartzitic schists of 

 Central Angonaland, 

 near and south of 

 Port Manning. The 

 muscovite - gneisses, 

 which occupy so 

 large an area be- 

 tween the Songwe 

 and Northern Ru- 

 kuru Rivers of 

 Northern Xyasa - 

 land, are also of 

 sedimentary type. 



o2 



