George Maw — Notes on the Mediterranean. 



553 



Still further westward, outside the Straits in the neighbourhood 

 of Cadiz, long ranges of low cliffs occur closely resembling the 

 raised beaches of Devon, and, like them, composed of a hard concrete 

 of sand and shells.^ The shells are, I believe, of recent species. This 

 raised beach would imply an elevation of the coast of 40 or 50 feet. 



Crossing to the African side of the Straits, further evidence of 

 recent upheaval is to be seen in level strata of sand and clay resting 

 on the edges of nearly vertical strata of older rocks. At Tangier 



Fig, 5. Low Cliff. Tangier Bay. 

 these occur at about 40 feet above the sea-level. They are probably 

 of Post-Tertiary age (though I was unable to verify this by the 

 detection of organic remains), and perhaps may be incidental to the 

 same upheaval that elevated the raised beaches of Cadiz. 



General Observations. — These observations, which apply to only a 

 very limited area of the great Mediterranean basin, are scarcely suf- 

 ficient to place in proper sequence the various oscillations of level it 

 has undergone, but may be brought into comparison with the abun- 

 dant evidences of recent changes of level on the Mediterranean coast 

 which have already been put on record. 



The well-known case of the Temple of Serapis, recorded by Lyell, 

 giving evidence of submergence and re-elevation within known 

 heights and certain limitations of historic time, suggests a compari- 

 son with other evidences of similar elevation ; and I would remark 

 that Lyell's estimate of the amount of emergence of the shell-bored 

 columns on the Italian coast agrees almost exactly with the amount 

 of elevation in other distant parts, implied by the raised gravel ridge 

 on the Cdrsican marshes, the great plain of shingle at the Ehone 

 delta and the lagoons of the south-western Mediterranean French 

 coast. Furthermore, Mr. Gwyn Jeffreys informs me that a recent 

 marine deposit, containing Galeomma Turtoni and other shells of 



margins at various heights extending nearly to its summit. I cannot, however, admit 

 that these recent oscillations of level can, as Mr. Smith supposes, be correlated 

 with the various dislocations the limestone formation has undergone. On the upper 

 part of the western face there is a general sloping sub-aerial contour which has super- 

 seded all surface evidences of structural dislocations, and both the denudation pro- 

 ducing this western slope, and the occasional evidences of higher shore-lines super- 

 imposed on it, must have been infinitely more recent than the great dislocations of 

 the limestone strata. 



1 It is sufficiently compact to be extensively quarried for building purposes. The 

 city of Cadiz is almost exclusively built of it. 



