The geology of Lincolnshire in eastern England largely consists of an easterly dipping succession of Mesozoic age sedimentary rocks, obscured across large parts of the county by unconsolidated deposits dating from the last few hundred thousand years of the present Quaternary Period.
Rocks from this and the overlying Mercia Mudstone and Penarth groups occur in the northwest of the county and along its western border but are generally concealed beneath a thick cover of recent deposits.
A range of rocks from the Jurassic Period occur within a broadly north-south outcrop which tapers markedly northwards from the Fens to the banks of the Humber around Whitton and Winteringham.
The Cretaceous sequence begins with the Wealden Group limestones, mudstones, sandstones and siltstones which occur from Gibraltar Point in a band which narrows northwestwards to the Caistor area.
To their east, and stratigraphically above them, are the sandstones of the Lower Greensand Group and beyond them the Chalk which gives rise to the Lincolnshire Wolds and extends to the North Sea coast but is obscured along the coastal margin.