Dfcemj^er 26, 1907] 



NA TURE 



18: 



lechner, quoted above, and many others, he has been 

 forced here to oppose the notion of a primitive crystalline 

 crust, revealed to us in a region of Archaean rocks, and 

 urges that the' oldest rocks in this district are of sedi- 

 mentary origin, penetrated by younger granites. " The 

 strongly contorted structure " (p. 99) " characteristic of 

 most Finnish gneisses ... is not a secondary phenomenon 

 in truest sense, but originated when the rock was in a 



melting condition." This is supported by a series of 

 photographs of rocks intimately penetrated by granite 

 veinlets. The author " regards the foliation of the 

 granites, where it is not of dynamo-metamorphic origin, 

 as formed by the incomplete melting and re-crystallisation 

 of schistose rocks. Also the spotting of granites, he 

 ascribes, in most cases, to the existence of incompletely 

 resorbed fragments of older rocks." 

 At the same time, he believes thai 

 the foliation of many Finnish granite- 

 was due to pressure after they hai] 

 become solid (p. 100), and that in Fin- 

 land " the basement complexes of th^ 

 typical Archtean sedimentary form 

 ations are often preserved." Bui 

 the base of the whole series iri 

 Fenno-Scandia has been meltnl 

 up ; mixed rocks, therefore, pla\ 

 a very important part in thi- 

 area. Hutton's conception of th. 

 circulation of types of rock througl 

 denudation of the crystalline massi- 

 and their gradual renewal, appear- 

 to Sederholm to be fully justi- 

 fied (p. 102). The word " migma- 

 tite " is proposed for the rocks thai 

 have been called by others " compu- 

 site gneiss." 



In Bulletin No. 21 Mr. Tanner con- 

 tinues his studies on the glacial 

 phenomena of Finmark, and urges 

 that, allowing for temporary advances 

 of the ice during a general epoch of 

 recession, the glaciation may here be 



regarded as continuous, without an j,.^^^ 



interglacial break. 



Turning eastward, we find Dr. 

 W. F. Hume reporting on the geology of the 

 eastern desert of Egypt (Ministry of Finance, 

 Survey Department, Cairo, 1907). Gold-mining was 

 carried on here in ancient days, and has recently 

 been revived ; the gold occurs in quartz-veins. The 

 present account of the geology is merely preliminary, 

 but includes the record (p. 29) of a new marine fauna in 

 the Cretaceous sandstone. 



In the " Administration Reports of Ceylon for 1906 

 (Mineralogical Survey)," Dr. Coomarasw4my records the 

 discovery of thorianite m siiu by Mr. Parsons in a vein 

 of pegmatite, to which the mineral was traced by follow- 

 ing up the alluvial deposits in the bed of a seasonal 

 stream. About 6 lb. of thorianite occur in a ton of the 

 wet decomposed pegmatite. A geological map of part of 

 the Kandy district is added to the report. 



\'ol. vi. of the " Records of the 

 Mysore Geological Department " con- 

 tains several coloured maps. It is 

 suggested that the manganiferous 

 laterite in the Shimoga district, now 

 being mined, may represent an old 

 lake-deposit. The work done by the 

 survey is of a wide character ; but 

 may we ■■.uggest that such terms as 

 " geology student " and " topo 

 sheets " do not fairly represent the 

 English language? 



The " Geologists' Report of Pro- 

 gress for September, 1903, to 

 January. 1907, for the Federated 

 Malay States," by Mr. J. B. 

 Scrivenor (Kuala Lumpur, 1007, price 

 I dollar), is another interesting piece 

 of evidence as to present geological 

 activity. A distinct foundation is laid 

 in this pamphlet for a conception of 

 the structure of the south end of the 

 Malay peninsula, but the dense vege- 

 tation is here, as in Borneo, a serious 

 obstacle to the explorer. On p. 18 

 there is a remarkable reference to Mr. 

 H. N. Ridley's discovery of an alga 

 xewicaiana. instrumental'in producing laterite. Of 



this we shall hope to hear much more ; 

 possibly Mr. T. H. Holland, the originator of the organic 

 view of laterisation, has already looked into the matter. 



Bulletin No. 3 of the New 'Zealand Geological Survey 

 contains Mr. J. M. Bell's reporj on the Parapara sub- 

 division, Karamea, at the north-west corner of the South 

 Island. It is well furnished with landscape illustrations, 

 as is usual with these publications, and a series of beauti- 



Philippinc Islands, 



fully executed maps is inserted in a pocket at the end. 

 The geological history of the district in Cainozoic times 

 emphasises our growing convictions as to the almost 

 vyorld-wide occurrence of the same physical phenomena in 

 certain geological epochs. In this corner of New Zealand, 

 as in central Europe and Armenia, for example, we have a 

 Miocene depression, with a marine invasion (see Fig. i), 

 occupying the valleys of the previous land, and then " a 



NO. 1 99 1, VOL. 77] 



