Research at St James' Hollow chalk pit

Post date: Nov 24, 2012 12:09:13 PM

November 2012

St James' Hollow chalk pit is a SSSI designated for its marine reptile fossils, notably Mosasaurus. In recent years the geological exposures have become less accessible because of vegetation growth and weathering, as this photo shows.

To improve access to the relevant fossiliferous horizons, Natural England are using funding from their Facelift programme. It is not known exactly where the fossils were found in the pit, so it has been necessary to do some investigative work involving Mosasaurus fossils from St James' Hollow in the collections of the British Geological Survey. The idea is to use the expertise of Network Stratigraphic Consulting Ltd to analyse and compare nannofossils in chalk preserved in the Mosasaurus fossils with sediment samples obtained from the pit. The nannofossils identified can then be compared with the standard UK Chalk biostratigraphy.

February 2013

Three sediment samples have been taken from the pit, including the highest and lowest exposed strata. Mosasaurus tooth GSM 122844 and jaw fragment GSM 114241 have been sampled.

The results have shown that the chalk in St James' Hollow belongs to Nannofossil Subzone UC16i (the 'Beeston Chalk'). Analysis of chalk from the tooth suggests that it came from the same Subzone, however chalk from the jaw fragment suggests it came from the overlying Subzone UC16ii ('Paramoudra Chalk'). As this horizon does not appear to be represented in the pit it suggests this specimen is likely to be misprovenanced.

You may download a copy of the full report (1.1 MB) by clicking the PDF link below.

It will now be possible to improve the exposure of Chalk strata in St James' Hollow in the knowledge that the relevant fossiliferous strata are still accessible.