328 Reviews — Falklandia. 



i. 



cannot be maintained ; his Gaisa system in particular includes 

 a large number of rocks of different ages. 



The oldest rocks in the south of the district are of pre-Cambriiin 

 age, comprising hornblende schists, quartzites, and crystalline 

 magnesian limestones ; towards the west, in Jori, is a region of less 

 advanced metamorphism with slates, dolomites, and Tolcanic rocks 

 resembling those of the Kiruna district in Sweden, while east of the 

 River Tana the country is mainly composed of gneisses and granites ; 

 both of these types are probably younger than the schists of the south. 



The oldest Palaeozoic zone in Finmarken resting on a peneplain of 

 erosion is a shale with Platysoleniles anttquissimus, a fossil found in 

 many places in the Lower Cambrian of Scandinavia and the Baltic 

 region ; this is supposed to be part of a Cystidean. This zone is 

 clearly a continuation of the Syolithus zones of Sweden and Norway. 

 Above this comes the very thick Porsanger Sandstone with shales 

 and dolomite, the latter enclosing laminated structures called by the 

 author stromatolites and referred by him to chemical precipitation 

 possibly brought about by algse. These structures and the silicified 

 layers in the dolomite strongly recall the characters of the Durness 

 Limestone, and the series is assigned to an Ozarkian-Canadian age. 

 Uncon form ably above the Porsanger Sandstone comes a younger 

 series with conglomerates and tillites, formerly included in the Gaisa 

 Series ; the tillites of the Varan ger Fjord were well described by 

 Sir A. Strahan in the Quarterly Journal for 1897. The author 

 concludes on what appears to be good evidence that these deposits 

 are of Ordovician or possibly Silurian age. 



All these rocks are again overlain in the Alten division of the 

 district by the mylonitic rocks of the Caledonian thrust zone. It 

 was formerly believed that these overthrust rocks were of pre- 

 Cambrian age, but there is no evidence to support this view, and it 

 is concluded that they are simply highly metamorphosed repre- 

 sentatives of the unaltered Palaeozoic rocks below the thrust. The 

 resemblance to the general succession as seen in the North-West 

 Highlands is obvious, and this memoir is of great interest on account 

 of its bearing on the problems of British stratigraphy. 



IV. — Falkland^. By J. M. Clakke. Proc. National Academy of 

 Science of U.S.A., vol. v, No. iv, pp. 102-3, April, 1919. 



IN the valuable monograph published in 1913 by the Geological 

 Survey of Brazil (Fosseis Devonianos do Parana), Dr. J. M. 

 Clarke included a discussion on the palaeogeography of the austral 

 lands in Devonian times. He pointed out that the extent of the 

 Southern Devonian shore faunas indicated the union of Gondwana- 

 land and Antarctis during Devonian times. The Devonian of these 

 latitudes is a unit both in life and sedimentation. In the present 

 short paper Dr. Clarke proposes the name "Falklandia" for the 

 " continental land which, during the Devonian period in the 

 occidental parts of the Southern Hemisphere, preceded Gondwana- 

 land and Antarctis". It is considered that other names, such as 

 Freeh's "South Atlantic Island", which have been suggested for 

 the Pre-Gondwana austral lands, have been founded on insufficient 

 evidence. 



