274 Reviews — J. E. Stead — Cleveland Ironstone and Iron. 



sandstones, shales, and doloniitic limestones. The later rocks are 

 diabase, and they extend in patches over a large area. 



A "Preliminary Memoir on the Lewes and JNordenskiold Rivers 

 Coal District, Yukon Territory ", by Mr. D. D. Cairnes (Memoir 

 No. 5, 1910), is descriptive of a varied series of formations, Pre- 

 Ordovician, Devonian (?), Carboniferous (?), Jurassic or Cretaceous, 

 Tertiary and Quaternary. Two horizons of coal are recorded in the 

 Jurassic or Cretaceous ; the higher beds, worked at the Tantalus 

 mines, being the more valuable. The seams are from 3 to 7-^- feet thick. 



"The Edmonton Coal Field, Alberta," is described by Mr. D. B. 

 Dowling (Memoir No. 8 E, 1910), and he estimates that, if mined 

 economically, the available quantitj' of coal is about 80 million tons. 



III. — Cleveland Ironstone anb Ikon. 



MR. J. E. STEAD, E.R.S., read a paper before the Cleveland 

 Institution of Engineers (Middlesbrough, 1910) on the Cleveland 

 Ironstone and Iron. The author deals with the micro-structure 

 of the Cleveland Stone, a subject illustrated by twelve photographic 

 plates. Silica is present in the oolitic iron-ore in concentric layers, 

 out no examples of oolitic limestone with silica envelopes could be 

 procured, although the grains in the Pickering limestone of Corallian 

 age contain much silica. Concentric layers of iron -pyrites (with 

 nickel and cobalt) occur in the oolitic ' sulphur bed ' of the Eston 

 ironstone. A piece of petrified wood in the Eston ironstone contained 

 90 per cent, of calcium phosphate and 10 per cent, of a peat-like 

 substance. In the Rosedale ironstone an ammonite was found in 

 which the segments and outer shell had been considerably changed to 

 ferrous carbonate. 



In seeking for portions of the original rock Mr. Stead found what 

 he believes to be a representative of it " imprisoned in the vertebral 

 column of a Plesiosaurus ". Analyses are given of the bone and of the 

 substance inside it. That of the latter, which consisted of oolite 

 closely resembling the ironstone itself, was as follows : — 



Dried at 212° F. 

 Ferrous Carbonate ....... 15'58 



Iron Pyrites . 



Alumina 



Silica . 



Calcium Carbonate 



Calcium Phosphate 



Magnesia 



Organic matter, etc. 



0-82 



7-00 



19-80 



51-16 



2-53 



1-67 



1-44 



100-00 



Iron 7-90 



Sulphur 0-40 



Phosphoric Acid . . . . . . . . 1'16 



One of the oolite grains shown in pi. xii, and representing rock- 

 material after treatment with hydrochloric acid, had evidently 

 consisted mainly of calcite, but near the exterior there were to be 

 seen a few concentric siliceous layers. Mr. Stead asks: " Does this 

 single grain not indicate an uninterrupted change, and point to 

 a process which, if continued, would have resulted in the complete 



