Marriott carries out deep mining exploration boreholes including boreholes for potash with particular experience in the use of heavy duty mining wireline systems for large diameter high quality core and the associated testing programmes. These coring systems have also been successful used in boreholes that have been side-tracked to obtain additional geometric control on formation structure for mine planning.

Similar heavy duty coring systems has been used by Marriott personnel for geological and hydrological investigations for potential sites for deep mined repositories for radioactive waste disposal in a range of geologies both in the UK and Europe. Marriott also drills wells for solution mining of salt deposits.