Abstract

In their otherwise excellent paper on the ‘Stratigraphy and geotechnical properties of weathered lodgement till in Northumberland, England’ Eyles & Sladen (Q. J, eng. Geol.14 p. 135) claim that the till sequence of east Durham needs to be re-examined in the light of the discovery that till sequences in Northumberland and North Yorkshire are simpler than once thought; the implication is that such re-examination would reveal that the east Durham sequence is also simpler than previously thought, and that the red-brown Upper Boulder Clay there is the weathered upper part of the Lower Boulder Clay.

All geological sections can benefit from periodic re-examination in the light of new discoveries and new interpretations, and extra details and perhaps new interpretations would emerge from another look at the east Durham drifts. But, having carefully examined all the cliff and valley sections of the Durham coast and traced the sequence between exposures by traditional field mapping, I cannot accept Eyles and Sladen's implication that the Middle Sands there might be a series of unconnected localized beds of sand and gravel at various levels within a single thick till sheet. Instead I re-iterate the view made clear in Geological Survey Six-Inch maps NZ 44 NW, 44 SW, 44 SE and 43 NE that for at least 9 km in cliffs stretching from near Hawthorn (NZ 44 46) to near Crimdon (NZ 48 37) there are two distinct tills separated by mappably continuous level-bedded sands and subordinate gravels that are only locally less than

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