Geological Society of London. 333 



the Wingewortb iron-furnaces, near Chesterfield, and was given to 

 me by Mr. Arthur Carrington, one of the owners. 



The furnaces have been lately blown out for repairs, and in the 

 mass of slaggy refuse at the bottom a thin layer of the curious pro- 

 duct known as Iron Amianthus was interposed between the sand and 

 the iron refuse. 



The red sand at the bottom of the furnace was converted in its 

 upper part into a compact hard white sandstone, an inch or two in 

 thickness, and upon the top of this the Iron Amianthus occurred in 

 snow-white fibrous masses, the fibres radiating in a concentric 

 manner, and forming moi'e or less botryoidal concretions, somewhat 

 resembling heematite in appeai'ance, and separated by extremely thin 

 plates or septa of iron, by which the entire mass is divided into 

 irregular prisms of about half an inch in diameter. 



A similar product is described by Percy as occurring in the blast- 

 furnaces of the Harz, and is said to consist almost entirely of fibrous 

 silica, with a few sj^ecks of iron and graphite, and minute cubes of 

 nitro-cyanide of titanium. Both graphite and titanium occur in the 

 Wingeworth refuse ; the graphite is found in thin plates, the nitro- 

 cyanide of titanium in masses of crystals. 



Percy states that the origin of the Iron Amianthus is found in the 

 oxidation of the silicon, which is separated in greater or less degree 

 under the same conditions as graphite, and is oxidized at a high 

 temperature. 



II.— May 28, 1884.— Prof. T. G. Bonney, D.Sc, F.E.S., President, 

 in the Chair. — The following communications were read : — 



1. "The Archgean and Lower Palaeozoic Eocks of Anglesey." 

 By Dr. C. Callaway, F.G.S. With an Appendix on some Kock- 

 specimens, by Prof. T. Gr. Bonney, D.Sc, F.R.S., President G.S. 



The object of the author was to furnish additional proof of the 

 Archaean age of the altered rocks of the island. He held that the 

 Pebidian mass on the north was fringed by Palseozoic conglomerates, 

 containing, amongst other materials, large rounded masses of lime- 

 stone, derived from the calcareous series on the north coast, these 

 conglomerates being probably a repetition by reflexed folding of 

 those which lie at the base of the Palseozoic series. In like manner 

 conglomerates which margined the western (Holyhead) schistose area 

 contained angular pieces of altered slate undistinguishable from 

 some of the Pebidian rocks of the north-west. These conglomerates, 

 dipped to the east, forming the western side of a syncline. Near 

 Llanfihangel were sections which showed not only the Archaean age 

 of the gneissic and slaty (Pebidian) groups, but also the higher 

 antiquity of the former. These conclusions were derived from the 

 occurrence of granitoid pebbles in the slaty series, and from the 

 presence of masses of the slate, as well as gneissic fragments, in 

 the basement Paleeozoic conglomerates. The author was at present 

 unable to accept the Cambrian age of the lower Palasozoic rocks, 

 and considered that the fossils he exhibited tended to confirm the 

 views of the Survey on the correlation of those strata. The paper 

 concluded with a sketch of the physical geography as it probably 



