. The Quarterly journal of the Geological Society of London. cesses must havebeen at work on similar deep-seated materials in each of thoseregions, these conditions being the controlling factors in thedevelopment of a petrographic province or of a number of similarprovinces in widely-separated regions. Analyses of the alkali-rocks of Madagascar, the Transvaal, Angola, and the Los Islandswere also plotted, but in none of these cases was there any resem-blance to the Mozambique curves, probably on account of theexistence of more than one series of differentiates in those Series B is
. The Quarterly journal of the Geological Society of London. cesses must havebeen at work on similar deep-seated materials in each of thoseregions, these conditions being the controlling factors in thedevelopment of a petrographic province or of a number of similarprovinces in widely-separated regions. Analyses of the alkali-rocks of Madagascar, the Transvaal, Angola, and the Los Islandswere also plotted, but in none of these cases was there any resem-blance to the Mozambique curves, probably on account of theexistence of more than one series of differentiates in those Series B is based on analyses of rocks from the Monapo-Riverand Sokoto-Hill districts. The analysis of the ground-mass ofhornblende-andesite is included, for it provides a good indicationof the course of differentiation towards the felsic end of the series. 1 Vol. ii (1913) pp. 576-90. 2 Geol. Sxirv. Prof. Paper 14 (1903). 3 Natural History of the Igneous Rocks 1909, p. 124. 4 Such, for example, as occur in the Christiania district; see A. Harker,op. cit. p.
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Keywords: ., bookcentury1800, bookdecade1840, bookidquarte, booksubjectgeology
