254 proceedings of the geological society. [feb. 22j, 



February 22, 1854. 



Charles Lindsay, Esq., C. H. Burbidge Hamley, Esq., and James 

 Augustus Caley, Esq., C.E., were elected Fellows, 



The foUowmg communication was read : — ■- 



On the Geology of the Mayence Basin. 

 By William J. Hamilton, Esq., Sec. Geol. Soc. 



Contents. 



Introduction, p. 254. 



Part I. — Extent of the Mayence Basin and stratigraphical account of its different 

 constituent beds, p. 255. 

 Extent of the area occupied by the Mayence Tertiaries, p. 255. 

 Description of the strata, p. 257. 

 Basement rocks ; red sandstone, &c., p. 257. 

 Tertiary rocks : — 



I. Marine Sand and Quartz-conglomerate, p. 260. 

 II. Lower blue Brown-coal Clay ; Cyrena-clay, p. 265. 



III. Cerithium-limestone, p. 266. 



IV. Littorinella-limestone, p. 268. 



V. Upper blue Brown-coal Clay, p. 271. 

 VI. Leaf-bearing Clay, p. 272. 

 VII. Ossiferous Sand, p. 272. 

 Part II. — On the Zoological Characters and Age of the Marine Molluscous Fauna 

 of the Mayence Basin, p. 273. 

 Table I. Mollusca of the Marine Sands of the Mayence Basin, p. 274. 

 Table II. Fossils of the Cyrena-clay, p. 280. 

 Table III. Fossils of the " Freshwater Limestone " of the Germans, 



p. 281. 

 Table IV. Fossils of the Cerithium-limestone, p. 282. 

 Table V. Fossils of the Littorinella-limestone, p. 284. 

 Table VI. Fossils of the Ossiferous Sand, p. 285. 

 Part III. — On the Ancient Geographical Character and Connection of the Sea in 

 which the Marine Fauna of the Mayence Basin was deposited, p. 288. 

 Comparison with the Tertiaries of Belgium, France, Switzerland, the 

 Vienna Basin, the Brown-coal, Magdeburg, Bavaria, and Wurtem- 

 berg, p. 289 ei seq. 

 Conclusion, p. 293. 



Introduction. 



The insulated position of the Mayence Basin and the abundance of 

 its fossil remains, particularly the marine molluscous fauna, had long 

 ago invested it with an interest for the geologist far beyond what its 

 limited extent would have led us to anticipate ; and which the in- 

 vestigations of the last few years, while they have made us better 

 acquainted with its fossil contents, have not yet exhausted. 



Since the time when Bronguiart first called attention to the fossils 

 of the Weisenau strata*, the geologists of Frankfort, Wiesbaden, 

 Darmstadt, Mayence, Hanau, and other places in the neighbourhood 

 have contributed their share towards the investigation of the peculiar 

 features of this formation. The results, however, are not generally 

 known in this country ; and, having lately had several opportunities 



* Memoire sur les Terrains superieurs calcareo-trappeens du Vicentin, et siir 

 quelques Terrains d'ltalie, de France, d'AUemagne, &c. 4to. Paris, 1823. 



