JOURNEYS THROUGH KOREA. lOT) 



pressing up of granitic magma seem to me to have taken place 

 on such a grand scale that the preexisting sheet crust was torn 

 asunder and buoyed up to an Alpine altitude. Then the land 

 was subjected to degradation which laid bare the hidden batholith, 

 leaving now the preceding three series in detached patches not 

 unlike pieces of orange peel. 



The masses of granite and orthogneiss that commonly ap- 

 pear as embossments protruding through schists over a great 

 area are usually regarded as the oldest known rocks and styled 

 " Primitive " or " Fundamental." The granites are still regard- 

 ed as the original crust, the associated gneiss as highly meta- 

 morphosed sedimentaries, and are known as the Laurentian for- 

 mation ^\ Writers on Korean geology inchiding myself have also 

 fallen into this habit of regarding the Granitoid series as the 

 Primitive. It is now known in many instances especially in the 

 United States, Saxony, and the Alps, that some granites and 

 gneisses are intrusions into schist series, and the gneisses are in 

 the main regarded as katamorphic granite, or according to 

 Weinschenk, piezocrystallized granite. 



IV. a. Palaeogranite. — As granites in Korea are of dif- 

 ferent ages, the group now under consideration may be better 

 designated as palseogranites '^ by way of distinction from 

 younger ones ''\ 



The dominant type of the palseogranite of the region is the 

 coarse magnophyric biotite -granite which has a special tendency 

 to become porphyritic and at the same time schistose in texture. 



1) Ck-xmberlin-Sfilisbury, " Geology," 1906, Vol. U. p. 143. 



2) Geh. Oberbergrath Credner has recently given the name palœogranite to the ^vell- 

 known graniilite (laccolith) of the Saxon Mittelgebirge, anil I have found it very convenient to 

 follow his good exami)le. EennntiationsiKOgramm : ' Die Genesis des sächsischen Graniilit- 

 gebirges,' 1906. See page 18j. 



