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VI.—On the Origin of the Cylindrical Cavities in certain Sandstones of the Fayûm, Egypt

Published online by Cambridge University Press:  01 May 2009

Extract

In an article published in a recent number of this journal, Dr. Henry Woodward discusses the origin of the curious cylindrical cavities which occur in such profusion in certain concretionary blocks of sandstone and on exposed rock-surfaces at two distinct levels in one or two localities in the Fayûm depression. These perforated rocks, first noted by Schweinfurth, were examined by me some ten years ago and referred to as “apparently the work of marine boring mollusca” in my memoir on the region in question. Both Dr. Schweinfurth and I had considerable misgivings in regarding the cavities in question as shellborings, but in my case, and I believe in his also, this explanation appeared to involve fewer difficulties than any other which suggested itself.

Type
Original Articles
Copyright
Copyright © Cambridge University Press 1911

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References

page 31 note 1 On some supposed Pholas-borings from the Shores of Birket el Qûrun, the ancient Lake Moeris, of the Fayûm, Egypt”: GEOL. MAG., 09, 1910, pp. 398402Google Scholar.

page 32 note 2 The Topography and Geology of the Fayûm Province of Egyptý: Survey Department, Cairo, 1905Google Scholar.

page 31 note 3 Submergence of the region in Middle Pliocene times to a level of between 60 and 70 metres (above present sea-level) is, I think, satisfactorily established on the evidence of the marine shell-bearing deposits of Sidmant, etc. Submergence to a level of 170–80 metres rests at present on somewhat unsatisfactory grounds, mainly (a) the supposed shell-borings at about 112 metres, and (b) the remarkable gravel terraces extending up to 180 metres above present sea-level.

page 32 note 1 See p. 401 of DrWoodward's, article.Google Scholar