THE EARTH'S CRUST.

Auckland Star, Volume LVIII, Issue 78, 2 April 1927, Page 21

THE EARTH'S CRUST.

GEOLOGICAL THEORIES. TESTING OUT IDEAS. Oec^ogica 1 . theories whi.-h lie is testing 'n tlie course "f a world tvur were put i'OKire the members of the Wellington Philosophical .Nx-iety in a popular f"rni by Dr. Bailey Willis. Professor of i, eulogy to the Stanford University. The coa-i« of all the countries :>oruerinu or. The Pacific Ocean, said the lecturer, hail Wen visited by him. He had observ?.! that mountain rar.gr-. were thrown up highest where the -jivnn wa=- .!eepe-t off the c-.a-t. ana it sevuu-d to him that there must be some forc-e boneaih the Pacific which wa« making the continents and mountains. was realised that the history of the earth was one of mountain ranges lifje-J up over a period of many cemuries. and worn away over another ransre of »vntnr:e-. the process ]>eing re;>eatej and again. At times there had been a plain, at other times great ranges. Today we lived in a period of very advanced mountain growth, because* the world's history had not often known such mountain ranges as we had to-dav. Ocean Contrasts. Were periodicities of mountain elevation synchronous, and the periods of wasting away synchronous all over ;he world, or were the operations lakins place at different periods? In Northern Europe and America, bordering the Atlantic, periodicity seemed identical, but when he turned to the Pacific he found that at the time in history when there were no mountains in Enror>e. ther-? were great mountains in the Purine, an i he lonn,] that the two ocean basins were unlikp. He ranie to the oonelusien that the Pacific Ocean basin, had a dif-

ferent history. I; seemed as though these ixij bayins had force? acting independently of each olber. The mountain-; <>: Chile. North Ameri--a. the Philippine*, ami some of the New Zealand mountains, all had a. closely paral-it-i hi-torv. They were ail young mountain-, raised in the youngest geological period, the pleistocene, but hfouu<i expat difference-. Then- na< a general populate tha; there was in the earth"- mi>; a horizontal force of compression, which ha J (Token or -beared the rook-, not oniv on the Mirr'aw. but to a depth of nfty miles. That was a -uifir-en , : ;■> rai-e mountain ranges. There were p..any rea-ons why snr-h a f"Tce fhou'.J exi-t. but a'l agreed that there was one. The materials with which in* »a"iealing were rook-, a: a dt-r-th of from l> lo 20 miles. Ma?se3 rocks couM no; bend up. uuder such a pressure, like a -'rip of il'iiigh. but when such pre»-.irt "•a? apjilieil they beared dicgoTiallv. at an with the earth's surface. ::;.- stronger tho pres?nre the iln--hoar. and :f the shearing was kor-t ii; the smaller bkx-k- niu-t move on each other. The horizontal pres-ure was thuturaed into a vertical upward pressure, which made the mountains. There «er<numb**r- of such mountains in ra!i:""rnia. and he hail the sarne forma:i>:: at Pembroke, on Lake War.ak.-i. Detective Story in Stone. Professor Willis deal; with the behaviour of fault- under continu-nl prvs--ure. Most faults »>re fund along-iJe huge masses of <rranite. Xot all faults were vertical, like tiie great GOO-mile fault on the Pacific <.V>a-t. Some were horizontal. Visiting the scene or the heavy earthquakes at Coquiinbo. in Chile, he had been puzzled to lind no vertical fault extending along the line of damage on the surface. Surmising a horizontal fault, and following out hie theory that the force that made the mountains bordering on the Pac:sc came from below the sea in the Paeine Qr-eau r-a-in. he had searched in the An.!<-«. 14.000 ft up. and rrany mill-- inland from tbe >-"»'!:e of iiio dsinapf. and had fo;a>l overtiirnst faults. Investigations show**! that there further overthrusi

fan.;? further on up the Andes, ap to £V.9uUit. and. ;eturr.in>r the coast, he had found tliru-t plane?, of them, at about *.x mile interval*, ail iiearin;: out the th«*ory that the fault- k-d down on a lor.z >.ar.T to far beneath the Pacific Th;- *a.i!v -arr.e structure a« n> found in tlse re<rar-!eil a- a f— -il -Tγ::t'.;re of hundred* of million* of _v,ar> vvt thl* pro\«il : at the --i:.fforivs were working :•■>.".., v. In America ;>p- had r.-'THe-i :!ia". £~.--~ ilr rariire- »rere in\ ar. .*■■'-}' hizh. quailed onlv by preat voican.x--. an i ho :---.ni ihe >a:iiv in -lar-an. He i-rTereU tbo tj—rv that i-oia>-i ::.a----- ZTan.te. jn :t-r horizontal ;.r«"-*urp. ;r<-T uj'S.-ir:-. f'iir" t.i ::n-:r .-ry»:a;!:n* f->rn:i::>'a. Granite wa« ..rie-.na!!-.- a ::.. ::on r> k. an.: .:- vry-»ai- »t>n- r .■•: ?."»-.z-■*. in any ;ian. :■.:'. ;—»in"•-.I in .»!". dire , "..on*, -o *:iat w!vn ■..- t_— ;■• cian , :ho;; ; :h- rr»ri:e injorna/.y chan^. , .' :o .» ™noi-i. «•'.!!• h ::.■■>•» fd in the d-rctior. o: !oa-t . . 1- the ma*npwanl* a- "he ;•'•- —:"•» r.>— -d :n. v uii mountain- -.1 •••A---i * ::-\i'n.?.; my a: The r «il2v*. k> vm: a< .1 n->-~al fau'i:. of Paciac Basin. W'.m: «"fro ti'if , f 1 •?.•"«••« :!i.t •«-.-.-'<.•; jr the :--i •">! the Pa<-i'>: Gravity had -a--f-- of the oarth'- -urfa.>- ni:h -••;i3d« v -i nn ier iTirta^" ,1 . n;it th:- vsas :-e----ratiic There ■xa- no to that any par: of the mass was heavier than ar.y otber. Therp reniained heat and molecnlar Heat C'-rtain'y relea-ed enerp". It seemed to that the of tr«lecclaT er>*rjy in rock wa? tlie caa?e o: the r-re--ure« beneath the earth'? surface. Why shoald thi~ energy be more marked in or beneath th* £rrea: ocean basin, saeh as that of the Pacific? He suzirested that the quality of the rock underlying it was the more sensitive to heat, to recryitallisation. or to meltinsr. and that it wi; tbe accumulated sinkinz :n of The cnisT on the f\r-"id'."::re of r-«*a: an.": e---™-. ~\ r rma".l ]io>ition< a: •!itT«-rrn*. p:'ri»»;i :H----had anuaJly icraied lie greater basin itself "