Seabed sediments represent an important long-term sink of carbon (Blue Carbon) in the Earth system over geological timescales. Mapping the spatial distribution and character of seabed deposits is essential for estimating blue carbon stocks in the deep ocean, and their significance for buffering the severity of atmospheric climate change. Australian marine ecosystems are considered a ‘blue carbon hotspot’, holding 5 – 11 per cent of global stores. The Blue Carbon Seascapes collaboration between Geoscience Australia and the Australian Institute of Marine Science is mapping and modelling the distribution of seabed sediments in targeted areas of the broad northwest continental shelf (~200 km wide) characterised by ridges, reefs, depressions and plains. Each of these geomorphic features hold sediments of different character and age, and varied organic carbon content. Here we present preliminary results from integrated high-resolution mapping using multibeam sonar, sub-bottom profiling and seabed sampling (grabs, cores). We apply novel semi-automated feature classification techniques to quantify sediment thickness and depositional architecture to constrain blue carbon estimates. We also discuss the potential application of these standardised geoscience methods to other settings