﻿part 3] 



VOLCANIC KOCKS OF MOZAMBIQUE. 



263 



but several specimens in my possession bear the most detailed 

 resemblance to the basaltic dyke -rocks of Mozambique. 



In the adjoining table, the distribution of the two series of 

 lavas is tabulated in as complete a form as the present state 



District. 



• 



' Calc-Alkali ' Series. 



' Alkali ' Series. 



Amygdaloidal 

 basalt. 



Andesite. 



Rhyolite. 



Alkali- 

 rhyolite. 



Alkali- 

 trachyte. 



Nepheline- 

 bearing lavas. 



Melilite- 

 basalt.* 



Deccan 



X 



X 



X 







X 





Southern Arabia 



X 







X 



X 







Somaliland 



X 







X 



X 



X 





Abyssinia 



x 



A 







X 



v 





Kordofan 



X 



X 



X 







X 





Lake Rudolf 



X 



X 





X 



X 



X 





Kavirondo 



y 



X 



X 







X 





Uganda Railway 



X 



X 





X 



X 



X 





Elgon . 













X 



X 



Kenya 











X 



X 





Naivasha 









X 









Masailand . 



X 



X 





X 



X 



X 





Kilima Njaro 





X 







X 



... 



X 



Meru 





X 







X 



X 





Songwe River 



X 



X 







X 



X 







X 



X 







X 



X 





Katanga 



X 





X 









X 





X 



X 



X 













X 











... 





Forest Vale 



X 















Southern Rhodesia . . . 



X 













X 



Zambesia-Pungwe 



X 



X 



X 









K 



Lebombo 



X 



X 



X 











Zululand 



X 



X 



X 











Drakensbergen 



X 



X 











2 



Chief amygdale- 

 minerals. 



Quartz, chalcedony, 

 opal , and lime- zeolites. 

 (Calcite not common, 

 but becoming more 

 abundant south of 

 Mozambique.) 



Soda-zeolites and calcite. 

 (Silica absent, except in the 

 rhyolites and more acid 

 trachytes.) 



* Melilite-basalt is included here, not because of any inherent richness in 

 alkalies, but because it seems often to be a complementary end-product of an 

 alkali series. 



1. Southern Rhodesia. 



2. Melilite-basalts and kimberlites (of later age than the amygdaloids) 



occur west of these localities in the Transvaal, the Orange Free State, 

 and Griqualand West. See map in P. A. Wagner's ' Diamond-Fields of 

 South Africa' 1914. 



