I.—On the relative Ages of the Coast Boulder-clay of the Eastern Counties, and that on the Higher Ground

Extract

The discussion on Mr. Boyd Dawkins's paper, “ On the age of the Lower Brick-earths of the Thames valley,” at the meeting of the Geological Society of London, 9th of January, induces me to submit a view of the relative ages of the Boulder-clays of the east of England, which seems to bring into harmony the views of Mr. Dawkins, and the physical evidence suggested in the discussion that seemed to conflict with them.

Mr. Dawkins' opinion that the lower deposits of Brick-earth at Grays' Thurrock, Crayford, and Erith were super-imposed by a Glacial deposit containing transported materials, was objected to on the grounds that they occur in a valley apparently excavated after the deposition of the Boulder-clay capping the high land to the north of London—implying an interval between the Muswell Hill Boulder-clay, and the supposed Glacial deposits of the Thames Valley, represented by the entire excavation of the valley, and the deposition of the Brick-earths and gravels, containing mammalian remains, underlying the Glacial beds.