ABSTRACT This paper presents a detailed sedimentologic data set of minor moraines (heights ≤2.0 m, widths ≤14 m, lengths ≤108 m) that formed beginning near the end of the Little Ice Age by Schwarzensteinkees, a valley glacier in Austria. Sorted sediment and stratified diamict dominate five exposures, and compact massive diamict exists in one exposure. This sediment is interpreted as proglacial outwash and subglacial till. Most moraine sediment shows deformation structures (e.g., smaller and larger folds), and some units contain evidence of water escape. Other units maintain their original subhorizontality. All moraines contain unequivocal evidence of having formed through deformation by pushing during ice-margin fluctuations. Minor moraines formed more specifically by three identified processes: (1) pushing of outwash sediment; (2) stacking and pushing of outwash sediment; and (3) pushing of outwash sediment and freezing-on of subglacial till. Our data suggest that the sedimentologic composition of the valley fill influences the style of push-moraine formation. In this case, the friable nature of outwash sediments can increase the efficiency of the pushing ice front and the likelihood of sediment collapse down the proximal ice-contact slope after ice retreat. This study contributes to our understanding of sediment transport and deposition in high-mountain environments.

Abstract The c. 450 km-long Brook Street Terrane (pre-Alpine Fault displacement) sheds light on processes of arc magmatism and related sedimentation. A very thick (up to 15 km) succession accumulated south of the Alpine Fault in the Takitimu Mountains during the Early Permian. Predominant arc-flank talus is intercalated with basic extrusive and intrusive igneous rocks. Volcaniclastic sediments mainly accumulated by mass-flow and turbidity current processes. The sediments were mostly derived from differentiated, arc-core, basaltic–andesitic rocks, contrasting with less evolved arc-flank flows and minor intrusions. Some igneous rocks are mildly enriched, supporting an extensional back-arc setting. After volcanism ended, Middle–Late Permian mixed carbonate–volcaniclastic gravity-flow deposits were derived from a non-exposed carbonate platform. Other volcanogenic successions in the south (Bluff, Riverton) represent smaller eruptive centres. In contrast, north of the Alpine Fault (e.g. Nelson), volcanism began with mostly felsic tuffaceous gravity-flow deposits, followed by extrusion/intrusion of clinopyroxene-rich, primitive magmas, related to arc rifting, and ended with an accumulation of a mixed basic–felsic volcaniclastic forearc apron. Taking account of regional comparisons, the Early Permian arc is interpreted as having formed adjacent to Gondwana (on accreted or trapped oceanic lithosphere), whereas the lithologies north of the Alpine Fault represent contrasting Late Permian continental arc magmatism.