In a series of recent articles, the possibility was raised that, owing
to the occasional impact of asteroids and comets in the oceans, lowla
nds on continental margins might be prone to superflooding (Huggett, 1
988a; 1988b; 1989a). It was suggested that a number of landscape featu
res, including diverted drainage systems, gorges, valley meanders and
extensive sheets of gravel might have been created by these superflood
s. At the conclusion of the 1989 article it was noted that many landsc
ape changes that might be ascribed to the action of superwaves are the
same as the landscape changes accredited to the Noachian Deluge by th
e old school of diluvialists led at its zenith in the 1820s by William
Buckland (see Huggett, 1989b). Thus, the bombardment hypothesis, thro
ugh its prediction of superwaves and superfloods, leads to a new brand
of diluvialism. This article explores the nature of neodiluvialism a
little further, drawing attention to a growing body of evidence sugges
ting that, owing to various agencies, truly catastrophic floods have o
ccurred in the past. It also discusses landscape features which can be
expected to have been fashioned by diluvial, rather than by fluvial,
action.