A study of twenty-seven subsurface drill cores allowed the delineation of seven recurring facies in the Viking Formation of the Chigwell area. These facies are: 1) muddy and sandy siltstone, 2) thoroughly burrowed sandstone, siltstone and shale, 3) pale burrowed sandstone, 4) cross bedded and apparently structureless (massive) sandstones, 5) massive clast-supported conglomerate, 6) burrowed and interbedded fine grained sandstone, shale and siltstone and, 7) burrowed and laminated coarse grained sandstone, shale and siltstone. Facies 1 and 2 reflect the sanding upwards successions that underlie the main sand-body at Chigwell. The main sand-body itself is largely made up of Facies 3 and a Facies 3/4 association; representing a low energy shoreface deposit that coarsens upwards from the lower shoreface (Facies 3) into middle and upper shoreface deposits (Facies 3/4 association and Facies 5). Facies 5, 6 and 7 represent transgressée deposits that unconformably overlie the main shoreface sand-body. The lower shoreface is almost totally biogenically reworked, with burrowing intensity becoming less pronounced upwards in the shoreface succession.

The pervasively burrowed fabric of Facies 3 indicates that it was deposited in a well oxygenated, low energy, lower shoreface setting with infrequent storm influence. The wide diversity and high abundances of dominantly deposit feeding trace fossils found in Facies 3 strongly supports this interpretation. The stratigraphic position of the Chigwell shoreface within the overall Viking stratigraphic nomenclature is somewhat problematic; recent work suggests that the Chigwell shoreface probably developed in response to either a third or fourth(?) order drop in relative sea level, or a relatively short duration stillstand event that punctuated an overall transgression.