An interesting looking sediment deposit had previously caught my eye located off the ledge at the top of the pot in the Soft South, Hallowe’en Rift, Mendip. It was a change of circumstances that prompted a review of our digging strategy and the development of Nick’s ‘alternative’ dig, now renamed ‘Can of Worms’ that prompted a bulk sample (about 1kg weight) to be taken on 03/02/2024. Subsequently, a sub-sample (c.200g) from the bulk was washed over a 63-micron test sieve to remove the silt/clay fraction leaving the sand- and gravel-size particles to be graded (see image below). Clearly evident is the abundance of iron/manganese spherules in the sample. These are thought to have accumulated in turbulent eddies during flood events during the Pleistocene period, the finer silt and clay particles having been winnowed away. The origin of the iron/manganese is the object of further ongoing research. The presence of iron/manganese spherules has been noted in previous sediment samples taken in Hallowe’en Rift but not in the same concentrations.
