492 GEOLOGY 



Glacial formations. (1) In the vicinity of Varanger fiord, in 

 northern Norway, Lat. 70 8' N., there is a bed of bowlder-bearing 

 rock (the Gaisa beds) 1 resting on a smoothed and striated pavement 

 of distinctive glacial type. The Gaisa beds rest upon the eroded 

 surface of a crystalline terrane, and have been thought to belong 

 to the oldest part of the Cambrian system, or to antedate it. (2) 

 Recent exploration in China 2 has shown the existence, on the Yangtse 



Fig. 369. Glaciated stones from the glacial beds at the base of the Cambrian 

 in China. (Willis, Carnegie Institution.) 



River, in latitude 30, of a thick formation (170 feet) of bowlder- 

 bearing rock of glacial origin, containing many striated bowlders 

 of diverse sorts of rock (Fig. 369). The glacial formation here lies 

 at the base of the Paleozoic, and beneath the series that carries the 

 Cambrian trilobites. 



Glacial formations of about the same age have been found in 

 Australia, and perhaps in South Africa. 3 The most probable 

 interpretation, with present knowledge, is that these bowlder- 

 bearing formations of Norway, China, and Australia (Fig. 370) 

 belong either to the transition period that accompanied and followed 



1 Reusch, Norges geologiske Undersoegelse : Det nordlige Norges Geolo- 

 gi, 1891. Also Strahan, Quar. Jour. Geol. Soc., Vol. LI II, 1897, pp. 137-1 I'-. 



2 Willis, Researches in China, Vol. II. 



3 David, Report of International Geological Congress at Mexico, 1907; 

 and Howchin Quar. Jour. Geol. Soc., Vol. LXIV, p. 234, 1908. 



