Physical and chemical characteristics of Units 2, 3, and 4 suggest an aeolian component. The silt size (4–8 on phi scale) fraction of Unit 4 is often >70% of the total mass, with grain sizes consistent with an origin as aeolian dust. Unit 3 is yellow brown in colour and often has the characteristics of a diamict with a major grain size component similar in size to Unit 4. Unit 2 is typically uniform in appearance and contains a predominantly kaolinite and illite clay mineralogy that contrasts strongly with a predominance of quartz in the underlying bedrock. A simple sediment budget indicates that the volume of Unit 2 could be accounted for by a combination of sheet and rill erosion within the catchment and additional aeolian deposition in the order of 4–8 t/km ² year.

Radiocarbon dates for charcoal recovered from Unit 2 indicate that some deposition was associated with cooler, drier conditions of the late Holocene ‘Little Ice Age’, approximately 200–600 years ago.