8. North Arnhem Land Region

The north Arnhem Land coast extends for 1872 km along the northern coast of the Northern Territory. The coast is largely undeveloped and most is aboriginal land. It faces generally north with the southeast trades blowing off to alongshore. This is a tropical monsoonal region with a distinct wet and dry season, the wet delivering river floods which bring terrigenous sediment to the coast; however coastal sediments remain roughly 50:50 quartz and carbonate. Tides are meso to macro and waves generally low seas except on more exposed easterly facing shores. The beaches are predominately tide-dominated with tide-modified in more exposed locations, while mangroves dominate the more sheltered shores. Barrier systems are limited and mainly low regressive beach-foredune ridges, with limited dune transgression on some east-facing sections. This chapter describes the processes operating along the coast and its beach, barriers and sediment transport, with the framework of primary and secondary sediment compartments.