Tors and Weathering on Mckeen Ridge, Cathedral Provincial Park
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C < National Library Bib1 iothwe natjmle CAN%OIANNTHESES I$of Canada ' ON MICROFICHE ,L /' "Landforms and Weathering on McKeen Ridge, -*CatfiedralPark, B C. " ' ~ITLEOF THESISITITRE DE LA TH~SEJ . DEGREE FOR WHICH THESIS WAS FESENTEDI Master of ARts , GRADE POUR LEOUEL CETTE THESE FUT PR~SENT~E rl YEAR THIS DEGREE CONFERRED!ANN~DrOBTENTlaY DE CE DEG~ tQ76 Professor F.F. Cunningham NAME OF SUPERVISOR/NOM DU DIRECTEUR DE TH.!?SE -- -r-- Permission is hereby granted to the NATIONAL LIBRARY OF L'autorkation est, par laprt?sente, accordbe 9 la BIBLIOTH& CANADA to microfilm this thesis and to lend or sell copies WENATIONALE DU CANADA de microfilmer cstte these et of the film. de prdter ov de vendre des exempleires du film. , ihe author reserves other publication rights, and neithei the L'autew se rbsirve' les autres droits de publication; ni,la , - thesis nor extensive extracts from it may be printed or other-, tht3seni de longs extraits de celle-ci ne doiveht Btre imprim& +. wise reproduced without'the aut&r's written perrnissien, w sutrement reprtnfuits sans /'autorisetion &its de. I'auteur. ,5 , . ' San Rafael, 7 I-- - - -*P / California 94903, U.S.A. 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Canadian Thes Division Division des theses canadiennes Cataloguing Br7 nch Di rection* du catal ogage National Librar"y of Canad? Bi bliotheque nationale du Canada Ottawa, Canada KIA ON4 Ottawa, Canada . KIA ON4 Y- BAKons,, University ef California, Berkeley, NU . %. A THESIS SUBMITTED LN PARTIAL FULFIL- OF THE REQUIREMENTS FOR THE DEGREE OF 7 MASTER OF ARTS in the Department Geography @ PAUL ZENOPE MELOOW 1975 SIMON WSER UNIVERSITY All rights reserved. This thesis my not be .reproduced in whole or in part, by photocopy - 7 or other means, without permission of the author. APPROVAL Name : Pau 1 Zenope Melcon Degree : Master of Arts Title. of ~hesis: Tors and Weathering on ~cKeenRidge, Cathedral Provincial Park, British cbldia -- - Examining CommitQe: ~ , -, P, Chairman: R.B. Horsf all. - --r,. - - - ,- V F.F. (Cunningham Senior 'Supervisor I . - . C. B, Crampton -, F - -.-, -- L.K. Peterson External Examiner Associate Professor Chbistry Departmen? - Simon Fraser Universiq -. Date - Approved : .+ .+ .% ' . PARTIAL COPYRIGHT LICENSE , --- - - 4 4 I hereby grant to Simon Fraser University the right to lend .I my thesis or dissertation (the title of which is showd beiow) to users of the Simon Fraser University Library, BW to make dartial or single copies only for 'such users or in response to a requcst from the library - of any other university, or other educational institution, on its'own I I , -& A ---- - beha16 or for one of its users. I further agree that permission for multiple copying of this thesis for scholarly purposes may be granted by me or the Dean of Graduate Studies. It is understood that copying or publication of this 'thesis for financial gain &hall not be allowed .- without my written permission. Title af Thesis/~issertation: , Author : , ,-_--, ,-- , , ,, ? ,- PAUL Z. MEXON -- 7 (name ) . - # August 20, 1975 . (date) = 4: Abstract This the;is, titled Tors and Weathering on ?&een Ridge, Catheiral , Provincial Park, British ~olumbi~,is an analysis of the morphogenesis of'a * tor landscaie located on an alpine ridge in the interior of British Columbia -- 4 in the light of a critical review of the scientific literaturewconcerned with tors and related topics. Tors are a bedrock landform having an unusual and - - -- - distinctive appeara ce which have been investigated by geomo~pbologistssince - 7- the middle part of the nineteenth century. Despite the considerable scrutiny .-a to which tors have been subjeebd, major questions regarding the origin and f. development of these landforms remain to be resolved, Specific problems inclu'de the age of particular tors, the climate and geomorphic conditions " under which they evolved, the effect of Pleistocene ice sheets and peri- glacial conditions on tors in middle and polar latitudes, and the changes 9 , occurring in tors exposedcto subaerial weathering conditions, Although many tors are regarded as havgng been produced by chemical deco&mition inva subsurface environment, this single explanation cannot be extended to all .tors. Tors have been attributed to either slope retreat or fmst action, and they have also been regarded as structural landforms or relict features. I I I The tors on McKeen Ridge were examined during field work in the summer and fall of 1974, and the surnmer of 1975. The field work consisted of geo- logic mapping, the collectionnf rock and fossil specimens, examination $2 . ..;- - of the landforms and geomorphblogy of the ridge, a seis&c,survey, and a thorough study of fie tors themselves. It was augmented by. laboratory examination of the rock specimans and residual materials, Experiments * testing ae- reaction of certain samples to simulated weathering conditions were conducted. A conc~usionof thisP€Fesfs is thXtFt6rs piissessing morphological characteristics .de,scribed-inthe text are azonal landforms having their origin by chemical weathering in a subsurface environinent and-are exposed at the sur,face by removal of @e unconsolidated products of weathering by -*. - erosional process&. ~lthou~~~chernicalweathering, deep regolsths and tor formation are often regarded as tropical phenomena, it is proposed that-deep that the rate of chemical decomposition of rock material is.greater than the . rate of removal of the products of' decompositign by erosional processes, '- Tors -cannot, therefore, be regarded as indicators of paleoclimatic conditions. The capacity of tors to survive periglacial conditions and subrergence beneath continental ice sheets has also been discussed. It is proposed that . deep weathering landscapes may 'have been present over wide areas in northern latitudes during the Tertiary. > Evidence obtained from field and laboratwy74 investigatians of,the tors - ..*e' on McKeen Ridge supports many conclusions reached in the literature review, The tors-are shown to be paleo-landforms having their origin in a subsurface environment by chemical weathering of quartz monzo&$te bedrock, The tors , were exhumed and then buried beneath lava flows an3 a fossiliferous sediment during the Eocene. Indirect evidence suggests that the tors my be as old - as' the beginning of the Tertiary, Paleoclimatic evidence from local 'fossils . in the Eacene sediment indicate the presence of a w , ,mist and equable "6" -- - - climate which was neither tropical nor subtropical, A low relief "peneplainH t - . 3 - g* - surface was present in this British Columbia during the Early .A C * 5 ? Tertiary. The combination of low relief (and therefore slow rates of denu- a r dation) agd an equable, mist climate fulfills the conditions necessary I -- - -- -- 7 for deep weathering to occur. Factors establishing the subsurface origin -of the tors include the morphologfc characteristics of the tots themselves, B * the degree o-f chemical alteration of the-quartz monzonite bedrock in which , the ,tors"are formed, and the pr5sence of weathered materials derived fiom . the quartz monzonite in the Eocene sediment. The tors were re-exhumed during s - * the Pliocene or Pleistocene and have sutvived submergence beneath Pleistocene , - + ice sheets. A new mechanism responsible for the origin of weathering pits s., s., - on tors is described. :-..., 2 - . The major contribution of the field work is the documentation of the r -6 age, climatic conditions and geomorphic environment under which these tors evolved. The tors constitute the oldest tor landscape tb e brigin of which 1 has been conclusively established, and the first tor landscape in which , direct evidence was 'present indicating that the tors evolved under-bid- latitude climatic conditions. - K 'I wish to thank Professor F.F. Cunningham, my thests supezvisor, r t - gr. C. B . Crampton, and Dr-. L. *K. Peterson *for their valuable criticism an& assistance in the preparation of this thesis. I wish< to acknoklede'Z. P. Melcon, M. C.cMelcon, D. J'. Uelcon, .B. A. Popelak,.E. M. Leonard, and W. A. Wetzel for their assistance in the field, I am particulakly 'indebted to &of essor-~unnin~&amfor k~-xf&alAs- - comments in the field, and-his enthusiasm and'interest in this thesis. , ,. I wish to thank my wife, &errill, for her unwavering assistance and 'loving support in the preparat ion of this thesis. art TABLE OF CONTENTS LIST OF FIGURES ............:...........-......,......,..,........,.. x - - - A -- - LIST OF PR(5FGRMI-G ..................................-.....,.-- -&.-. xi .< r? Introduction ........,.........................,,.,.........,.....-..-* r 1 Tr Physiography ........,..........................................-...