On Northern Glacial Drifts: Some Peculiarities and their Significance

Abstract

Geological conceptions are not always infallible, and it is as well that, on occasion, their foundations should be examined with some care. Probably they will prove to be sound, but there is always the possibility that some grave defect or omission may be discovered. From such a scrutiny the present communication has resulted: it is concerned with the origin of those major components of our glacial drifts, the boulder-clays and their interstratified sediments. The orthodox view on these matters is well known and widely accepted. Ever since the land-ice versus submergence controversy died down, boulder-clay (or till) has been regarded as “ground-moraine”, with or without englacial detritus—in exceptional cases as englacial detritus alone—while the sediments indicate periods of recession, of deglaciation. If there is a multiple series of these drifts, then each successive till marks a readvance, however slight, and eventually we get a record of ice-front oscillations, as so frequently happens with modern ice-sheets. The consensus of opinion is remarkable, not only in this country, but abroad. The one serious trouble seems to be over the extent and duration of the recessions. The monoglacial school hold that they were too brief and too slight to be considered interglacial, but of late years the multiglacialists have gained ground, having received support from many quarters. Such is the view, embodied in the vast majority of publications; as with most general statements, it needs qualification. More than sixty years ago, Goodchild (1875) held that the drifts in his northern Pennine area were