part 1] THE PBE-CAMBKIAH ROCKS OF MOZAMBIQUE. 31 



2. The Pre- Cambrian and Associated Rocks of the District 

 of Mozambique. By Arthur Holmes, D.Sc, D.I.C., 

 A.R.C.S., F.G-.S. (Read June 20th, 1917.) 



[Plates VIII-XL] 



Contexts. Pag . e 



I. General Description of the Area 31 



II. Succession and Classification of the Rocks 37 



(a) The Coastal Districts. 



(b) The Ampwihi Crossing. 



(c) The Bibawe Mountains. 



(d) The Nrassi Basin. 



(e) Fort Chinga District. 

 (/) West of Eibawe. 



(g) General Sequence and Classification. 



III. The Crystalline Schists 44 



IV. The Crystalline Limestones 46 



Origin of the Crystalline Limestones. 



V. The Gneisses and Gneissose Granites 52 



(1) Biotite-Gneisses and Gneissose Granites. 



(2) Accessory Minerals (Heavy Besidues) from the Bio- 



tite-Gneisses. 



(3) Hornblende-Gneisses and Amphibolites. 



(4) Garnetiferous Gneisses and Eclogite. 



(5) Origin of the Gneisses. 



VI. The Granulitic Granites and Pegmatites 67 



(1) Pegmatites. 



(2) Granites and Biotite- Granites. 



(3) Augite- Granites, Augite-Quartz Diorites, etc. 



(4) Butile-bearing Bocks. 



(5) Granulitic Norite. 



VII. The Granites and Massive Pegmatites 76 



(1) Biotite- and Muscovite-Granites. 



(2) Graphic Granite and other Quartz-Felspar Bocks. 



(3) Pegmatites with Special Minerals. 



(4) Quartz-Veins, 



VIII. The Pyroxenite- and Picrite-Dykes '. 80 



IX. Heavy Besidues from Crushed Bocks and Biver-Deposits ... 82 

 X. Correlation of the Gneisses and Granulitic Granites of 



Mozambique 84 



(1) Correlation of the Gneissose Granites. 



(2) Correlation of the Granulitic Granites. 



XL The Origin of the Inselberg Landscape 89 



Faults and Joints. 

 XII. Summary 94 



I. General Description of the Area. 



Beyond the coastal and volcanic belts of Mozambique — already 

 described in a previous contribution J — the country assumes the 



1 A. Holmes. ' The Tertiary Volcanic Bocks of Mozambique ' Q. J. G. S. 

 vol. lxxii (1916-17) pp. 222-79. In this paper a brief account of the explora- 

 tion of Mozambique was given, together with a bibliographj' and other pre- 

 liminary matters. A further introduction to the subject-matter of the present 

 contribution is considered, therefore, to be unnecessary. 



