East Midlands Geological Society

Speaker: Paul Hildreth, General Secretary and Past President, Yorkshire Geological Society

The county of Lincolnshire is often overlooked as a venue for geology field trips and even research but it possesses several opportunities for examining significant and interesting exposures. The Elsham Sandstone is a unique, local deposit within the Kimmeridge Clay Formation and at Welton-le-Wold neighbouring sites offer exposures of three glacial tills and an interglacial gravel deposit. 

The county’s jewel in the crown however is the under-published Lower Cretaceous sequence coeval, at least in part, with the very well-known Wealden Group of south east England and the enigmatic Speeton Clay of Filey Bay. This ‘East Lindsey Group’ is unique to Lincolnshire. It thins northwards to feather out north of Caistor and experiences facies changes in the area beneath The Wash which pass into an East Midlands suite transitional with those of the south of England. 

The impact of the ‘East Lindsey Group’ is threefold. It has influenced the shape of the western edge of the Lincolnshire Wolds producing an attractive fringing landscape between the broad Upper Jurassic (Oxfordian - Kimmeridgian) clay vale and the Chalk scarp. It has supplied three locally-important and distinctive building stones that can be recognised in the villages and towns of East Lindsey. It has provided the raw material, ironstone, for a relatively short-lived but locally important mining industry, the scars of which are still visible in the hillsides and valleys of the Claxby and Nettleton area. 

The various lithologies and palaeontology of the rocks comprising the ‘East Lindsey Group’ allow for a reconstruction of the palaeogeography of the Lincolnshire area during early Cretaceous times (145 – 113 million years ago) and its relationship with other parts of the present day United Kingdom.