Fig. 3

Bulk compositions of volcanic ash samples. Sample compositions are plotted according to magma type as total alkali (K2O + Na2O) versus silica (SiO2). Data for Snæfellsjökull sample (Snae-1) from Martin and Sigmarsson [77]
Bulk compositions of volcanic ash samples. Sample compositions are plotted according to magma type as total alkali (K2O + Na2O) versus silica (SiO2). Data for Snæfellsjökull sample (Snae-1) from Martin and Sigmarsson [77]