(rLASSIFlGATlON OF META.MOIM'IUC rKOCJESSES 401 



iiig the bedding of sediments which had been npturned before their final 

 recrystallization was completed. 



In a hiter paper (1910, page 44) Milch sliows the lilveness between load 

 metamorphism and the "normal metamorphism" of de Beanmont and the 

 "regional metamorphism'' of Danbree. 



Branns (1896, page 2T8) adopts "Belastungsmetamorphisnms/' giving 

 "regional metamor])hism'' as synonym; he notes the strong contrast of 

 both to "dynamic metamorphism'' in meaning. 



x\fter many years of field-Avork in the older Precambrian (Shuswap) 

 terrane of British Columbia, G. M. Dawson (1901, page 64) concluded 

 that "the foliation of the Shnswap rocks may have been produced rather 

 beneath the mere ^\'eight of superincumbent strata than by pressure of a 

 tangential character accompanied 1)y folding." In his summary of Brit- 

 ish Columbia geology, he continues with the remark: "In the Archean 

 of eastern Canada, foliation still nearly horizontal or inclined at low 

 angles often characterizes considerable areas and appears to call for some 

 explanation similar to that above suggested [for the Slmswap rocks] ." 



While mapping the later Precambrian (Beltian) formations of southern 

 British Columbia and i^lberta, the present writer independently came to 

 the view that load metamorphism is of superlative importance. Later 

 Avork in the Shuswap terrane itself confirmed that conclusion, in which 

 the A\riter found he had been anticipated by Dawson, as well as by Milch, 

 who first gave this general, process its name." 



In eloquent addresses to two international congresses, Termier (1903, 

 1910) uttered timely protests agaiiist exaggerated claims for dynamic 

 metamorphism. His reasoning was based on his experience in the west- 

 ern Alps. Translated, his words (1903, page 580) are: "Wide areas of 

 the Alps seem to have enjoyed relative trancjuillity and, in any case, to 

 liave undergone neither intense folding, nor cru.shing, nor cleaving. . . . 

 And, nevertheless, the metamorphism of the crystalline terranes is as 

 intense as elsewhere.'' He believes their rocks had already become crys- 

 talline schists before the great foldings and overthrusts characteristic of 

 the Alps took place. The relatiojis are like those obser\'ed in nature ])y 

 Dawson, Milch, and others; but Termier preferred to use, in. explanation, 

 the older term "regional metamorphism" to Judd's "statical metamor- 

 phism" or j\Iilch's "load metamorphism." In fact, Termier emphasizes 

 the rise of juvenile gases with tlie consequent heating of geosynclinal 

 strata, rather than ^■ertical stress, as rhe controlling condition of the re- 

 crvstallization. 



3 See summary repovts of the Geological Survey of Canada, 1911, page 168, and 1912, 

 page l-")0: also memoirs of the Geolojiical Sur\cy of Cauuda, number 38, 1912, page 172, 

 and inmiluT 08, 191,"), [»age 41. 



