130 Reviews — Thrust Movements in Norway. 



Iddings, J. P. Igneous Bocks, vol. i, 1909 ; vol. ii, 1913. 



Lindgren, W. Amer. Journ. Sci., ix, p. 269, 1900. 



Shand, S. J. "On Saturated and Unsaturated Igneous Bocks " : Geol. Mag., 



(V) X, p. 508, 1913 ; (VI) I, p. 485, 1914 ; (VI) II, p. 339, 1915. 

 "ABecording Micrometer for Geometrical Bock Analysis": Journ Geol., 



xxiv, p. 394, 1916. 

 Tyrrell, G. W. "A Beview of Igneous Bock Classification": Science 



Progress, No. 33, p. 60, July, 1914. 



EEVIEWS. 



I. — New Light on the Caledonian Thrust Movements in Norway. 



VOL. IV, part i, of the Norsk GeologisJc Tidss/crift, just published, 

 contains a summary of an exceptionally interesting paper on 

 the tectonics and formation of the Norwegian mountains, read before 

 the Geological Society of Norway by Professor V. M. Goldschmidt, 

 of Christiania University. 1 As the Norwegian and Scottish Highland 

 rocks are of similar age and nature and exhibit the same type of 

 tectonic structure, the discoveries in one region cannot fail to be of 

 interest to the workers in the other : the chief points of the paper 

 are here noticed without any attempt to offer criticism. The main 

 conclusions advanced are of a novel character and have more than 

 a local significance, for the author uses them to elucidate the problems 

 offered by the rocks and structures of other great mountain ranges of 

 the world. 



The paper deals with the central Norwegian mountain region in 

 which great masses of eruptive gabbro and granite have been thrust 

 over Ordovician phyllites. A series of arkoses, conglomerates, and 

 schists, known as the " Hoifjeldskvarts " (high-mountain quartz) is 

 usually present overlying the phyllites, and an attempt is made to 

 elucidate the hitherto problematical origin and age of the series, to 

 show its relationship to the high mountain eruptives which frequently 

 overlie it, and to demonstrate the conditions under which the 

 Caledonian mountain-building thrust movements obtained. The 

 great difficulty experienced in unravelling the nature and origin of 

 the " Heifjeldskvarts" results from the extreme metamorphism to 

 which a great part of it has been subjected. Thus, if it were possible 

 to classify its green schists and determine their origin, much light 

 would be thrown on many problems, but as yet there is no means of 

 doing this, lor a tuff, an agglomerate, a conglomerate, an effusive or 

 intrusive mass may all on alteration give the same kind of amphibolite 

 schist. A district was therefore chosen for investigation in which 

 the regional metamorphism is a minimum, and there are fewest 

 hindrances in the way of an indisputable identification of the rocks. 

 Such a district was found in Central Norway to the east and west of 

 Valdres, north-west from Christiania. 



In the first tract discussed, that between Valdres and Gudbrandsdal, 

 the sedimentary origin of the " Heifjeldskvarts " can be established 

 beyond doubt. The series here occupies an extensive area, and 



1 V. M. Goldschmidt, " Om hoifjeldskvartsen I og It": Norsk Geolorjisk 

 Tidsskrift, Bd. iv, Hefte i, pp. 44-6, 49-53, Kristiania, 1916. 



