Captain Spratt on the Geology of Varna, 151 



the district, are more durable than the underlying marls, &c., and 

 have a thickness of about 20 or 30 feet. They consist of a stony 

 mass of Nummulites, Operculince, and Orbit oides, With. Pectines, Tere- 

 hratulce, and Ostrcdce. This harder portion of the superficial rock has 

 become apparently weather-worn into vertical pillars, either isolated 

 or still connected above by an horizontal layer of hard rock which 

 has resisted the destructive action of the weather. Capt. Spratt 

 observed that in some places in the vicinity the surface-rock was 

 split by vertical cracks, so as to resemble an open pavement. These 

 fissures, operated upon by atmospheric agencies, illustrate, in the 

 author's opinion, the method in which the columnar fragments above 

 alluded to, and other masses more or less spherical, remaining on the 

 land, must have originated. The Nummulites contained in the dis- 

 integrating rock have not been destroyed, but remain intact, lying 

 about in heaps around the remaining nodules of limestone. 



Capt. Spratt referred to the possibility of this columnar state of 

 the hard rock of the upper marine series having been brought about, 

 during the period which intervened between the deposition of the 

 marine series and that of the freshwater beds overlying the marine 

 series in the neighbourhood, by means of water- action ; as it is 

 possible that the columnar surface of the degraded eocene beds may 

 have been covered up by the later deposits, and subsequently re- 

 excavated. This opinion seems to be supported by the fact of 

 columns occurring in a part of the Bay of Varna, at about 5 fathoms 

 depth. But Capt. Spratt leans to the opinion that the columnar 

 degradation is atmospheric, modern, and in actual progress. 



Capt. Spratt then described the geology of the coast north of 

 Varna. The Eocene deposits (yellowish limestone and sandy marls) 

 occur as far nearly as Mangalia. The reddish freshwater sands and 

 marls then come in, overlying, and form generally the steppes of the 

 Dobrudja. Land shells occur in some of the upper beds of this 

 district. The author then dwelt on the points of correspondence 

 between the rocks composing the termination of the Balkan with 

 those of the Crimea, and of the steppes of the Dobrudja with the 

 northern part of the Crimea. 



Capt. Spratt proceeded next to consider the age of the overlying 

 red marls and sands ; and pointed out their resemblance to the fresh- 

 water deposits on the northern shore of the Sea of Marmora, on the 

 Macedonian coast, the northern end of Euboea, and the Locrian 

 shore. In fact, almost all the Thracian peninsula is composed of 

 freshwater deposits of brown and grey marls and sandstones, nearly 

 horizontal and attaining about 500 feet of thickness, which appear 

 to be contemporaneous with the upper pleiocene freshwater deposits 

 on the western side of the Archipelago, in Eubcea and Macedonia, 

 and in Rhodes, &c. on the south. 



The author concluded with a notice of a post-tertiary or recent 

 marine deposit on the coast of the Dardanelles at a height of about 

 15 or 20 feet above the present sea-level. 



4. " Notes on the Geology of Trinidad." By H. G. Bowen, Esq., 

 F.G.S. 



The northern district of the Island of Trinidad, with the islands 



