Vol. 65.] THE KARROO SYSTEM IK NORTHERN RHODESIA. 439 



Mr. H. B. Mattfe took exception to the term graben being 

 applied to those valleys described by the Author which did not 

 seem to be due to trough-faulting. 



Dr. J. "W. Evans reminded the Fellows that the Lower Grondwana 

 coalfields of India, which corresponded in age to the Karroo beds, 

 were similar in structure to the outliers of the latter described by 

 the Author, being bounded on one side by a powerful fault towards 

 which the strata dipped. He also suggested that the progressive 

 decrease of the gorges from north-east to south-west might be due 

 to a diminution of the rainfall in that direction, instead of a 

 progressive extension of the faulting. 



Dr. F. H. Hatch said that it was not apparent from the brief 

 reference that had been made in the paper to the ' Fundamental 

 Complex,' which in places was also described as Archaean, how 

 much of the South African succession that expression was meant 

 to cover. He wished therefore to ask whether the Author had 

 found any evidence for the existence in Northern Rhodesia of one 

 or more of the great sedimentary and volcanic systems which in 

 the Transvaal and Cape Colony occurred between the oldest 

 schistose formation and the Permo - Carboniferous Dwyka, and 

 possessed a total thickness of at least 50,000 feet, without counting 

 the gaps represented by several great unconformities. 



Mr. A. B,. Andrew said that he had no personal knowledge of 

 the Author's districts, but had some acquaintance with the country 

 near Lake Nyasa. "With regard to the basal conglomerate in the 

 Luano Valley, the Author had mentioned boulders of quartz and 

 quartzite only, none of gneiss. In two instances in Nyasaland, 

 where he believed he had found a basal conglomerate, the majority 

 of the boulders were of gneiss. He congratulated the Author on 

 his paper. 



The Author expressed his thanks for the manner in which the 

 paper had been received. Answering Mr. Andrew, he stated that 

 gneiss- and schist-fragments only occurred in the brecciated basal 

 deposit, not among the conglomerate which was made up of smooth 

 pebbles. As to Dr. Hatch's question, he included such limestones 

 and quartzites as were found among the rocks of the complex under 

 the category of pre-Karroo. 



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