STRUCTURAL IMPLICATIONS OF WATER DISSOLUTION IN HAPLOGRANITIC GLASSES FROM NMR SPECTROSCOPY: INFLUENCE OF TOTAL WATER CONTENT AND MIXED ALKALI EFFECT

Abstract

To study the effects of total water content and alkali substitution on the structure of aluminosilicate glasses, two series of glasses belonging to the ternary system Quartz (Qz)-Albite (Ab)-Orthoclase (Or) were synthesized and investigated with nuclear magnetic resonance (NMR) spectroscopy. Series I consisted of seven glasses with normative composition Ab39Or32Qz29 (AOQ) and water contents ranging from 0 to 6 wt%. Series II consisted of dry and hydrous glasses (∼2.0 wt% H2O) with five compositions along the join Qz37Ab63-Qz34Or66 (AQ-OQ) varying the alkali content (Na/K) at constant Si/Al ratio. All glasses were investigated with 1H, 23Na, 27Al and 29Si magic angle spinning (MAS) NMR.