C II A TT ER IV. 



Tin: TKKTIAUY PKPOSITS OF Oil. 



In tl)c introiluctory cliaptcr, I Imve aln-ady alliuU-d to tljc remiirkable fact, 

 that tlit'rc Ls a groat (liffcrcncc Ix.'lwt'cn tlie ililuviiil licds niiil tlic btruta lioucatli 

 tliem. As a nile, tlusc tlilnvial Leils are aUo liiviiloil; \vc cau oftcti very i-afily 

 find a lino wlikli scpjvratcs tlic uppi-r diluvial loam from the lower diluvial IhMh, 

 and which is truly a line of untomfornntlUlt'j. This Is quite natural, a« the 

 upper diluvial formation— according to what is said, in tin) preceding chapter— 

 hiV5 liecn dejiositcd in a perfectly difl'eitjnt way. The lower diluvial strata, n'>t 

 intennixed with any product.^ of glacial action, are eminently confonwable. 

 Thus another line of partition, another true lino of viicomformabilify beconiM 

 highly important. It is fomied at some distance from the surfiux of the soil, 

 although, of course, that dish^uce varies and is often so gn-at tiiat the lower strata 

 arc not exjiosed. The appearance of this line is very nicely exhibiteil in s<^me of the 

 localities which I am to mention, e. g., at Oji, Fig. 4 and at Kanagawa, Fig. 2 & 3. 



At Oji. the very lowest jiart of the exposure shows the line of )io8iti«in 

 and the strata below it in a i»iu)ilar way. as they are seen in deep cuttings. 

 At Kanagawa, the line of luiconfonnahility a|>i>ear8 uuich higher, as it «loes alsti 

 in a great jwrt of the bluffs near Yokoliama. Thos<' at Kanagawa, a jiortion of 

 wliich I have designed, arc very near the Kanagawa statifm. and Ix'tweeu the 

 railway and the sea. They give perhaj« the liest iilca of the true nature of that 

 line, which here takes an undulating coiuye. ami so lieci'iues very clear, although 

 there is no visible ditVcrence in the angle of dipping lietween the two fonnations. 

 In other instances wc cau very easily recognize such a difference: for inst^ince, in 

 the blufl' of the sen side south-west of Yokohama. The dir is more than 



4 degrees, and amounts up to C degrees, the lower stnita lieii.. :. il to ihe we«t 



whilst the upper strata continue to lx> horizontal. This diilereuce would lie in<Wd 

 perfectly sufficient to prove that this unconformability is more than wlint i« nKually 

 seen lict ween twosulH'rdinatediv' ' '"i formatimi. evi n if the anijlos of dipping 



of the inferior strata \v;is not son ^leater. At Jiukegawa and lx:twtvn this 



place and the town of Jlito. it i» very often alx>ut 10", and never below 8*. whilst 

 in some places it rises to 14'. the <lirection of dipfiing Iwing here nearly or 

 exactly north. Thus wc find the lower '" *' i undulating through<nit. and 

 its upi>er limit is (Hiitc irregular in con > , .f the erosive action of water 



diiriug a subsequent periotl, after which another MKlimentary formation was 

 deposited. 



If we do not confine ourselves to the plain of Tokio, we rindeviu le» 



of dipping within the fommtion immediately underlying lliequarteri: ; -it«. 



In the province of Cliichibu, the 8and.«tone, conglomerate and shale, mentioned 



