A guide to a new Geographical Information System for the Chalk of the Thames Basin : the Thames Chalk Information System (TCIS)

BGS work on the Chalk Group of the Thames Basin has amassed large quantities of geological information about thickness, facies, marker-beds, biostratigraphy and structure, only a small part of which is incorporated into the geological map. More recently there has been wider use and interpretation of borehole data to underpin the development of 3D geological models. There is a pressing need to organise these disparate data in a way that can easily be compared and interrogated, as well as to capture the results of relevant published research outside BGS. This project addresses this need by creating a new spatial database, the Thames Chalk Information System (TCIS). The database uses ArcGIS technology to display key information layers about the Chalk. As well as standard topographical and geological information, TCIS includes layers describing: Group, Subgroup, and formational thickness; structural data; detailed stratigraphical data; coverage of 3D geological models that include units or surfaces of the Chalk Group; regions where data coverage limits our understanding of the Chalk. Hydrogeological data is currently being compiled as part of a related project; it is not currently available for incorporation into the TCIS, but will eventually be added. Basic information about the content and methodology used to compile the data in the TCIS is outlined in the main body of this report. Hydrogeological data was delivered through a separate project, and its features are the subject of a separate report. The aim of this report is to provide sufficient background information to allow meaningful use of the TCIS database; there is no new data interpretation.