34'G Ccaplaiii Puillon-Boblaye o«. the Tidal and other Zones 



but sometimes even polished. In supposing them to have the 

 same origin, we ought not to be astonished at this difference ; 

 it results principally from the action of atmospheric agents, and 

 from that of alluvial waters, which has filled them with ochrey 

 clay. Tlie position in which these surfaces is observed is a 

 new proof of their origin ; we see them either on the flat lands 

 (plateaux) at the foot of the mountains that constitute the limit 

 of iho tertiary district, or at the summit of passes (cols), and 

 seldom on the sides of valleys. Besides, they are always su- 

 perficial, and I have never happened to see them in the in- 

 terior of the limestone, although I have travelled during a 

 period of two years through a country where we meet every- 

 where naked sections, many hundred yards in height. The soil 

 of Modon and that of Navarino, as well as the pass which sepa- 

 rates these towns, and above all the ditches of their citadels, 

 show that these cavities, scooped here in the nummnlitic chalk, 

 are superficial, and that their level is superior to that of the ter- 

 tiary district, notwithstanding the contrary appearance produced 

 by the dislocation of the soil. I have already stated that I 

 have never seen these cavities filled with any other substance 

 than ochrey clay mixed with pebbles ; the tcitiary district has 

 never appeared to me to extend so far, and there is likewise in 

 it a breccia with a crystalline cement, which we meet always in 

 the vicinity of these decayed surfaces, and which I believe to 

 be of the tertiary epoch *. 



These last observations would require to be verified with the 

 more care, as they alone would be sufficient to determine the 

 epoch of the excavating of these cavities, always nevertheless 

 attending to the difference of the levels, for they could not have 

 been filled, either because they arc posterior to the deposition of 

 the recent formations, or because they occupied, at the time of 

 their formation, a higher level. 



In recapitulation, we must conclude, from tlie existence of 

 normal grooves, or those of the greater declivity, that the 



• Figure 1. shews a littoral cave near to Napoli, elevated from 5 to 6 fa- 

 thoms above the present level of the sea, filled with a ferruginous breccia ; 

 this breccia belongs to the present epoch. It contains fragments of antique 

 pottery, and the cave itself belongs to a slight and very recent upraising of 

 the coast of this part of Argolis. 



