XI.—Another View of the Submergence of the British Isles during the Glacial Period

James D. Hardy
1893 Geological Magazine  
James D. Owing to the fact that the addition of fresh silica often destro3 r s all traces of the growth-stages of a flint, very little information can be obtained when the process is complete and the nodule a mere solid mass of flint. Fortunately there are innumerable cases to be found in every stage of development, and those who care to look can find them in most districts of the S.E. of England where the Upper Chalk exists. The absence of flint in our lower beds' would of course be explained
more » ... ourse be explained by the assumption that only half the beds were above the sea-level when the process of segregation was going on. I may, in conclusion, reduce my suggestions to the following propositions :-1st. That Flint in the form now found in the Chalk was deposited subsequent to its upheaval above sea-level. 2nd. That whilst the large quantity of siliceous sponge spioules present must have had a considerable share in the formation of the nodular and perhaps the tabular flints, yet quite as frequently various other hard substances and even empty spaces assisted. 3rd. Chalk flints grew after the manner of crystals [or concretions?] and were regulated by similar laws. TUNBRIDGE WELLS.
doi:10.1017/s0016756800170566 fatcat:ue7zsoprj5akxccrjzlhyhfvxm