568 SCIENCE PROGRESS 



Prof. Garwood and Miss Goodyear deal with the Long- 

 myndian and Silurian of the Old Radnor district, and note an 

 algal development in the Woolhope Limestone (Q.J.G.S., 1919* 

 74, pt. 1, 1-30) ; while Mr. L. D. Stamp describes the upper- 

 most Siluran rocks of the Clun Forest district, and demon- 

 strates an uninterrupted transition from Upper Silurian through 

 Downtoniani to the Old Red Sandstone (Q.J.G.S., 191 9, 74, 

 pt. 3, 221-46). 



The Coal Measures and Magnesian Limestone of Durham 

 are described by C. T. Trechmann and D. Woolacott in two 

 papers, that on the Magnesian Limestone being by Dr. Woola- 

 cott alone (Geol. Mag., 1919, 203-1 1 ; 452-65 ; 485-98). Mr. 

 Linsdall Richardson continues his detailed researches on the 

 Jurassic of the West of England in a paper upon the " Inferior 

 Oolite and Contiguous Deposits of the Crewkerne District, 

 Somersetshire" (Q.J.G.S., 1919, 74, pt. 2, 145-73). Mr. H. J. 

 Lowe gives a useful resume of the Tertiary geology of Devon- 

 shire and Cornwall {Trans. Devon. Assoc, for the Adv. of Science, 

 Literature, and Art, 191 8, 1, 391-401). 



Knowledge of the regional geology of the North Atlantic- 

 Arctic region has been considerably advanced by the publica- 

 tion of a group of important papers. The Geological Survey 

 of Norway has published a large memoir upon the geology of 

 the Kongsberg district, an Archaean region containing impor- 

 tant silver mines associated with fahlbands believed to be con- 

 nected with diabase dykes of later age (Norges Geol. Undersok., 

 191 7, 82, 272, with English summary). 



An attempt has been made by O. Holtedahl to outline the 

 probable distribution of land and sea in the North Atlantic 

 and Arctic regions during various periods of Palaeozoic time 

 (Amer. Journ. Sci., 1920, 49, 1-25). This brings out the re- 

 markable homology in geological structure, and relative ages 

 of folded zones, between eastern North America and North- 

 western Europe, although the arrangement of the different 

 structural elements is reversed in the two regions. 



Baron de Geer has written what will become a classical 

 paper on the tectonic history of Spitsbergen under the too 

 modest title of " The Physiographical Evolution of Spits- 

 bergen " (Geografiska Annaler, 1919, H. 2, 161-92). Its scope 

 is best indicated in his own words : " The plan of this paper 

 is to describe the main structure-lines of Spitsbergen, its divi- 

 sion into a Northern Oldland and a marginal horst along the 

 west coast. Further, an extended Cretaceous base-level plain, 

 a great Tertiary submergence, followed by a late Tertiary re- 

 elevation of the horst and eastward overfolding of the adjacent 

 table-region ; considerable faulting along the west coast and 

 the fjords, in the latter case proved by measured warpings of 



