This expedition brought together Imperial College’s Underwater Club and the Departments of Geophysics and Geochemistry to develop and test underwater scientific techniques for mineral prospecting. The project aimed to support geophysical and geochemical investigations by providing divers capable of seabed sampling, equipment handling, probe placement, and on鈥憇ite monitoring.
The expedition was motivated by renewed interest in Cornwall’s mineral potential. Although Cornwall had a long mining history, much of its offshore geology remained poorly understood. Divers equipped with Aqua鈥慙ung systems offered a solution for seabed access at depths up to 200 feet, enabling sampling and instrumental support essential for exploration techniques not suited to underwater environments.
Work focused on two main areas: St. Ives Bay and Mounts Bay. Divers supported sparker surveys—acoustic profiling systems used to map subsurface geology—by observing electrode flotation depth and assisting with calibration. They also helped develop underwater temperature鈥憄robe methodology aimed at detecting anomalous heat flow associated with possible ore bodies.
A major component of the season involved extensive geochemical sampling, including sand, seaweed, and rock collection, using shovels, grab samplers, augers, and later an underwater pneumatic chipping hammer supplied by Holman Ltd. Sampling grids at quarter鈥憁ile spacing produced hundreds of specimens for laboratory analysis. Special bulk鈥憇ampling lines were also established to investigate suspected tin鈥慴earing areas such as Prah Sands and Porthleven.
Divers additionally monitored corers, dredges, and other experimental devices, providing real鈥憈ime performance observations. Over the season they logged over 69 hours underwater and collected hundreds of geochemical samples, while ensuring strict safety procedures.
Supplementary geological and biological studies documented seabed geology, sediment types, wave鈥慻enerated ripple patterns, and associated marine life, contributing to broader understanding of Cornwall’s sub鈥憁arine environment.
