THE ARCH^AN FORMATION OF THE ABLTKUMA PLATEAU. 205 



itj cut out of the rock.s along tlie Jeft bunk oi' the river. Thi.s road we 

 call the " Gozaisho döri.'' 



The l^asal member lies in a S(jmewhat elevated p(jrti(jn of the 

 plateau (Takaiuiki, 315 m.) on the west, while the eastern half of 

 the .section comjjrises tlie younger series. The bedding- of the rocks is 

 always disturbed, and that uf the Gozaish(j complex in ]xirticuLir, 

 wherever it can l)e detected, as is frequently the case, is vertical. 

 If we take into consideration, however, the enormous jammino- 

 together which the rcjcks ha\e undergone, we can easily imagine as a 

 result the cc^mplete parallelism of all the structural planes, affording 

 a- false appearance of a continuous section at right angles to the plane 

 of deposition. Hence it is not safe to infer much from a twenty-three 

 kilometers section of schists as to the orii>inal ncjrmal thickness. It is 

 evident, however, that such thickness must have Ijeen enormous. The 

 right half of the section, grou[)cd t<)gether Ijy me. in one series as the 

 Gozaisho rocks, seems to be tolei'al)lv free from üreat and iu'e^'ular dis- 

 turbances, and to l)e all tihcd u[) in xertical [)osition ; and of these 

 schists I venture to advance figures for the thickness, which is pro- 

 baljly not less than 10,000 meters. 



The thick mass of the (îozaisho schists terminates on the east 

 near Ivadöno, being there c<jvered by netirly horizontal layers of the 

 tertiary shales and sandst(jnes. At n«) great distance from this spot, 

 brown coals are now being profitably worked in the same bed. At 

 Negishi, a greenish, fine- textured, rather massive sidii.st crops out along 

 the banks in a vertical posilicjn with a slight incliriation towards the 

 east. It has the aspect of a clastic rock, and is like a, hardened deposit 

 of volcanic ashes, with here and there, not infmpiently, wliite, garnet- 

 bearing quartzite (marked Q m the sectitjn C-D). 



This is followed to the west Ijy alterniite bands of green and 

 white schists, intruded into at times by a hornblende-granite (H (r). 



