Contents.
Introductory Remarks.—In his Survey 'Memoir on the Geology of North Wales,' p. 207, Professor Ramsay remarks "how necessary it is to map every possible formation in detail before we can arrive at just conclusions concerning either the completeness or the fragmentary nature of the succession of strata." It is only by keeping a keen outlook in a particular district or districts for new sections that such details can be obtained. As regards drift-deposits, sections are likely to vary so much with the extent of the excavations, the state of the weather, &c., that, before they can furnish reliable facts, it is necessary that they should be leisurely and repeatedly observed. Though familiar with a number of sections around the estuary of the Dee for many years, I have lately seen the necessity for making a series of more connected and systematic observations than time had previously permitted; and as some of the sections may soon become obliterated, I lose no time in communicating the results to the Geological Society.
Results of Additional Visits to the Dawpool Sea-coast Section.—Since the time I very briefly described this section in the Quart. Journ. Geol. Soc. for Nov. 1872[1] I have often visited it, and on
- ↑ I must here correct two errors into which I was led during my earlier visits to Dawpool (Quart. Journ. Geol. Soc. for Nov. 1872). The grey facings of the fractures in the upper clay are not a chalk-wash, as was suggested to me by an eminent geologist; and their nature and origin have not yet, I believe, been satisfactorily explained. Though not at the points where I then examined the Dawpool cliffs, the upper clay of Cheshire does contain much decomposing "greenstone," as well as the lower. Both clays contain carbonate of lime, which, if it did not come from the chalk of Ireland, may have been derived from the limestone of Westmoreland, N.W. Lancashire, or W. Cumberland.
