60 KEPORT— 1867. 



Notes on the Perseberg Iron Mines, Sweden. 

 By C. Le Nete Fostee, B.A., D.Sc, F.G.S. 

 These mines are situated near the town of Philipstad. The ore, which is ma<T- 

 netite, occurs in the form of more or less thick deposits, pai-allel to the beddinop of 

 the surroimding rock. The rock, or " country," is hiiUeJiinta, which is regarded by 

 Swedish geologists as a very fine-grained gneiss. In the immediate neighbour- 

 hood of the ore, however, the " coimtry " consists of a rock made up of garnet, 

 hornblende, epidote, and varieties of augite ; limestone is sometimes present. The 

 author then compared these Swedish deposits with some \&vy smaU beds of mag- 

 netic iron ore found in the Crown's Rock, Botallack Mine, St. Just, Cornwall. 

 The magnetite occurs here imder veiy similar conditions. Both deposits were 

 considered to have existed originally in the form of beds in sedimentary rocks, 

 like the Cleveland iron ore for instance, and to have been since metamorphosed ; 

 the fact that the ore is accompanied by garnet, hornblende, &c., is explained by 

 the supposition that it was the ore that furnished the iron which enters into the 

 composition of these minerals. 



An Account of the Progress of the Geological Survey of Scotland. 

 By A. Geikie, F.li.S. 



The author showed the mode in which the sui-vey is carried on, describing par- 

 ticularly the manner of filling in the geological features of each district of the 

 country on the Ordnance Siu-vey ]Maps. Upwards of 3000 square miles altogetlier 

 have already been surveyed. Hitherto the work has been kept back by the small- 

 ness of the staff and the backward state of the Ordnance Survey; but the staff has 

 now been largely increased, and as the Ordnance Survey ^laps of the whole of the 

 south of Scotland are now ready, the work will be much more rapidly proceeded 

 with. The area geologically surveyed includes the district from the mouth of the 

 Tay to Berwicli on Tweed, and fi'oni the eastern end of Strathearu to the sources 

 of the Tweed ; also portions of the counties of Ayr, Wigtown, Kirkcudbright, 

 Lanark, and Ecnfrew. Five sheets of the one-inch map have been published, and 

 others are in preparation. Maps on the scale of six inches to one mile have been 

 issued for the coal-fields of Edinburgh, Haddington, and Fife, and others for the 

 Ayi'shire coal-field are engraving. Two sheets of horizontal sections acro.ss Edin- 

 biu-ghshu'e and Haddingtonshire have been published ; also one sheet of vertical 

 sections of the Edinburgh coal-field. Three memoirs, descriptive of Sheets 32, 33, 

 and 34 of the one-inch map have appeared. Large collections of fossils and rock- 

 specimens have been made in the course of the sm-vey. 



Oil Tertiary and Quaternary Deposits in the Eastern Counties, with reference 



to Periodic Oscillations of Level and Climate. By the Rev. J. Gunx, 



M.A., F.G.S. 



The author stated that periodic changes in the level of land and water and of 

 (•limature had been assigned by men of science to astronomical causes ; and that 

 imder the impression that if such were the fact, the effects of such periodic changes 

 might still be traceable, he had examined the Tertiary strata in the Eastern 

 Counties. 



He specified and described at length three several oscillations of level from the 

 period of the forest-bed to the termination of the glacial epoch ; and after pointing 

 out advantages in many respects derived from thus tracing the sequence of strata, 

 he expressed a hope that others might be led to make a similar inquiry in older 

 beds, so as to ascertain whether the supposed relation between astronomical and 

 geological cycles holds good or not. 



The author was of opinion that, considering the length of time that had elapsed 

 since the cojnmencement of historical evidence, during wliich scarcelv anj' geo- 

 logical change was pereejitible, the precessional cycle was too .short, and that such 

 changes must be referred to a longer cycle, to v.'hich the precessional was sub- 

 ordinate ; and lie further indulged in the hope that, if tJie length of the cycle were 

 ascertained, and the numbers of such oscillations counted, supposing, of course, that 



