Cxi PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



the importance of geological knowledge to the practical minera- 

 logist. 



Onr indefatigable member Capt. T. Spratt, R.N., has extended 

 his inquiries into the Eastern part of the Dobrutcha, and has favoured 

 ns with some remarks in continuation of his former paper. The 

 flanks of the Northern chain of mountains, in itself composed of 

 highly inclined limestones, shales, and slates, are smoothed down, as 

 it were, by a deposit of arenaceous and variegated marls. These 

 marls are considered of recent date ; and though not fossiliferous, 

 Capt. Spratt now considers that this group of superficial marls of 

 the Steppe is distinct from the freshwater marls, or lower fresh- 

 water deposits, of Kustenjeh. At the north-east of the Dobrutcha 

 there are older rocks, which Capt. Spratt considers to be in a me- 

 t amorphic condition from volcanic action, and, in his opinion, to have 

 been either Devonian or Carboniferous ; to them he assimilates the 

 thick beds of dark shale which occur at the south-west corner of the 

 Easelm Lagoon, where the Delta of the Danube commences ; they 

 resemble the shales and schists on the flanks and base of the Balkan, 

 near Cape Emmeneh. In the coast- cliff a secondary limestone is 

 observed to overlie the shales, whilst it immediately underlies the 

 superficial earthy marls of the Steppe. Capt. Spratt had no oppor- 

 tunity to search for fossils amongst the deep beds of shale, sometimes 

 amounting to 500 or 600 feet in thickness ; but the fossils found by 

 him in the limestone appear, from the examination of our Assistant- 

 Secretary, Mr. Rupert Jones, to correspond with those of the second- 

 ary section of the white limestone of the Mediterranean : and I use 

 the term " section" because, as I have on a previous occasion observed, 

 the same physical condition is preserved in the limestone from the 

 Jurassic into the tertiary epoch as is shown in the Ionian Islands, 

 and more especially in the Island of Paxo, where Nuinmulites in 

 great abundance occur in connexion with flints, and with the general 

 characteristic appearances of the hardened chalk. Some of thephysical © 

 changes which have taken place in this region are highly interesting. 

 The limestones Capt. Spratt supposes to have stood as ridges, rocks, 

 or islets in a freshwater lake, which once covered, in his opinion, the 

 whole area of the Black Sea and Archipelago, and which has left 

 evidence of its existence in several freshwater formations, both of 

 marls and lhnestones. Following in succession the hard porcelain- 

 like limestone, Capt. Spratt notices a chalk-marl and a limestone of 

 a more truly cretaceous character ; but even these would appear not 

 to be clearly determinate in age, were it not that Mr. Jones states 

 that a Yentriculite and Cretaceous Foraminifera occur amongst the 

 fossils. I shall conclude my brief notice of Capt. Spratt's researches 

 by observing that the base of the tertiary system is in several local- 

 ities observed to be, as at Varna, and at Sevastopol on the opposite 

 shore, a limestone oolitic in structure, — a fact which confirms my 

 observations of the continuance of a prevailing mineral type through 

 a vast range of organic life. 



Another brief but very interesting paper, " On the freshwater 

 deposits of the Levant," may be considered supplementary to the 



