There are still relatively few hydrochemical studies of glacial runo and meltwater routing from the high latitudes, where non-temperate glacier ice is frequently encountered. Representative samples of glacier meltwater were obtained from Scott Turnerbreen, a `cold-based' glacier at 788 N in the Norwegian high Arctic archipelago of Svalbard, during the 1993 melt season and analysed for major ion chemistry. Laboratory dissolution experiments were also conducted, using suspended sediment from the runo. Signi®cant concentrations of crustal weathering derived SO 2À 4 are present in the runo, which is characterized by high ratios of SO 2 À 4 : SO 2À 4 HCO À 3 and high pCO 2 . Meltwater is not routed subglacially, but ¯ows to the glacier terminus through subaerial, ice marginal channels, and partly ¯ows through a proglacial icing, containing highly concentrated interstitial waters, immediately afront the terminus. The hydrochemistry of the runo is controlled by: (1) seasonal variations in the input of solutes from snow-and icemelt; (2) proglacial solute acquisition from the icing; and (3) subaerial chemical weathering within saturated, ice-cored lateral moraine adjoining drainage channels at the glacier margins, sediment and concentrated pore water from which is entrained by ¯owing meltwater. Diurnal variations in solute concentration arise from the net eects of variable sediment pore water entrainment and dilution in the ice marginal streams. Explanation of the hydrochemistry of Scott Turnerbreen requires only one major subaerial ¯ow path, the ice marginal channel system, in which seasonally varying inputs of concentrated snowmelt and dilute icemelt are modi®ed by seepage or entrainment of concentrated pore waters from sediment in lateral moraine, and by concentrated interstitial waters from the proglacial icing, supplied by leaching, slow drainage at grain intersections or simple melting of the icing itself. The ice marginal channels are analogous neither to dilute supra/englacial nor to concentrated subglacial ¯ow components.