GEO assignment (Z009)
NATS 1750 A (Winter 20 17): Assig nm en t 3, Ve rs io n 1 .0 - Feb ru ary 2 0, 2 017 Due: March 15, 2017 by 11 p m ED T v ia Mo odle (Late Penalty: 25% per da y - in cl udin g w eeke nds. St rict ly enfo rce d.) Instructions: ● You are expected to p ro vide a nsw ers fo r eve ry q uest io n. Y ou a re e nco ura ged to sh ow all of your work so th at ma rks can b e a w ard ed fo r part ia lly co rre ct a nsw ers.
● Although you are enco ura ged to co lla bora te w it h yo ur cl assm ate s, e ach o f yo u is expected to submit a se para te a nd d ist in ct a ssi gnme nt - a p oin t th at w ill r e quir e acknowledgement u pon su bmi ssi on.
1. Using Google Maps (o r a si mi la r ma ppin g ca pabilit y):
a. Provide the la tit u de a nd lo ngit u de fo r a fe atu re o f yo ur ch oosi ng o n M ount R oya l.
[2 marks] b. Using your ma p, o r so me o th er so urce , p ro vide a n e st im ate fo r th e a lt it u de o f Mount Royal. (Be ce rtain to ci te yo ur so urce o f th is est im ate .) [1 m ark] c. Using your ma p, o r so me o th er so urce , p ro vide a n e st im ate fo r th e a lt it u de o f area around Mo unt R oya l. (Be ce rtain to ci te yo ur so urce o f th is est im ate .) [1 mark] d. Using your ma p, p ro vide a th re e-d ime nsi onal p ict ure o f M ount R oya l th at illustrates it s relie f re la tive to th e su rro undin g a re a. B ase d o n yo ur a nsw ers 1(b ) and 1(c), provide a q uantit a tive e st ima te fo r th e re lie f o f M ount R oya l. [4 m arks] e. Based on your answ er to 1 (d ), e st ima te th e mi nim um d epth o f r o ck th at th e Mount Royal w ould h ave re quire d fo r in tru sion (a s an ig neous plu to n - i. e ., assume Mount R oya l in tru ded in to a p re exi st in g st ra ta o f se dim enta ry ro cks. ) [2 marks] f. Through use o f a ske tch , p ro vide a g eolo gica l re co nst ru ct io n fo r M ount R oya l around the time a t w hich th e in tru sion to ok pla ce . A dd ske tch es th at p ro vi de before and a fte r illu st ra tio ns. [3 ma rks each = 9 m arks; a dd 3 b onus m arks fo r 3 D block diagrams] g. Provide a geolo gica lly so und n arra tive to a cco unt fo r M ount R oya l’s evo lu tio n through use o f yo ur ske tch es - fro m th e p ast , th ro ugh to h ow it a ppears to day. [3 marks] © L. I. Lumb - Sharing proh ibited. V iolat ors subject to legal and/or academ ic consequences. 1 2. Locate a geological ma p o f Mo unt R oya l (e .g ., Plandow ski 's o r Eby’ s Fig ure 3 ).
a. Prepare a geolo gica l cro ss sectio n th at tre nds Ea st-W est . Y our cr oss sectio n should be to sca le , a nd in te rse ct w it h th e th in U tica sh ale lit h olo gy th at is pre se nt at the easte rn mo st e dge o f Mo unt R oya l. L abel e ach lit h olo gy on yo ur cr oss section, and in dica te w hich fu ndame nta l ro ck typ e it r e pre se nts. In a ddit io n to your cross sectio n, p ro vide a n a nnota te d ve rsion o f th e g eolo gica l m ap yo u u se d to indicate th e lo ca tio n o f yo ur cro ss sectio n in ma p vi ew . [1 0 m arks] b. According to yo ur cro ss sectio n, w hich lit h olo gy (o r lit h olo gie s) h as th e M ount Royal pluton in tru ded in to ? [2 ma rks] c. From your g eolo gica l se ctio n, e st ima te th e th ickn ess of th e U tica sh ale lit h olo gy at the easte rn mo st e dge o f th e p lu to n. [3 ma rks] d. According to Bo dyco mb (2 001), th e me ta mo rphic aure ole e xt ended fo r a bout 8 00 m. Indicate th is on yo ur cro ss sectio n b y ext endin g a n 8 00 m th ick re gio n fr o m the edge of th e la st ig neous lit h olo gy in to a se dim enta ry one. [4 m arks] 3. According to Eby: “. ..th e in tru sion is in co nta ct w it h O rd ovi cian sh ale s (U tica fo rm atio n) and limestones (Trento n fo rma tio n) th at h ave b een me ta m orp hose d to th e p yr oxe ne hornfels facies.” And, a cco rdin g to Bo dyco mb, ma ximu m te m pera tu re s were e st im ate d at ~500 ℃ , while pre ssu res would h ave b een re la tive ly lo w ( le ss th an 2 kb ars) .
a. Given this conte xt , w hich p olymo rph o f Al 2 SiO 5 mi ght yo u e xp ect to fin d in a sample of the h orn fe ls ro ck fro m th is lo ca tio n? U sing th e Phase C hange animation fo r Al 2 SiO 5 , lo ca te th is polymo rph o n th e p re ssu re -te m pera tu re g ra ph provided. Obta in a scre ensh ot o f yo ur gra phica l in te rp re ta tio n th at in cl udes a representatio n o f it s cryst allin e sh ape. [2 ma rks] b. Suppose that d urin g a n e arlie r st age o f co nta ct m eta m orp hism te m pera tu re s were above 7 25 ℃ , a nd p re ssu res were h ig her. U sing th e Phase C hange animation fo r Al 2 SiO 5 , lo ca te th is polymo rph o n th e p re ssu re -te m pera tu re g ra ph provided. Obta in a scre ensh ot o f yo ur gra phica l in te rp re ta tio n th at in cl udes a representatio n o f it s cryst allin e sh ape. [2 ma rks] c. Suppose that a t so me time in th e d ist ant fu tu re , a sa mple o f th e m in era l produced in Q uest io n 3 (a ) is burie d to a p re ssu re in e xce ss of 4 .0 kb ars, w it h out a change in te mp era tu re . U sing th e Phase C hange a nim atio n fo r A l 2 SiO 5 , lo ca te this polymorp h o n th e p re ssu re-temp era tu re g ra ph p ro vi ded. O bta in a scr eensh ot of your graphica l in te rp reta tio n th at in cl udes a re pre se nta tio n o f it s cr yst allin e shape. [2 marks] d. Provide a pro ce ss-f lo w d ia gra m th at ma kes use o f T he R ock Cycl e to a cco unt fo r the scenario d escri bed in Q uest io n 3 (c). [3 ma rks] © L. I. Lumb - Sharing proh ibited. V iolat ors subject to legal and/or academ ic consequences. 2 4. Age relationships.
a. The sedimenta ry rocks, th at Mo unt R oya l h as in tru ded in to , d ate b ack to th e Ordovician. Est ima te th eir yo ungest -p ossi ble a ge, a nd a dd th is in fo rm atio n to your sketches. [5 ma rks] b. Eby provides ages fo r th e ig neous ro cks th at co mprise M ount R oya l. E st im ate this age and a dd it to yo ur ske tch es. Kn ow in g th at th e o f th e h orn fe ls fa ci es ro cks (Question 3) are th e b yp roduct o f co nta ct me ta mo rp hism , w hat is th eir a ge m ost likely to be? Exp la in . [8 ma rks] c. Are these rela tive a ges, i. e ., yo ur answ ers to q uest io ns 4(a ) a nd 4 (b ), co nsi st ent with the intru sion h yp oth esi s? Exp la in . [2 ma rks] 5. The origin of Mount R oya l re ma in s a ma tte r of so me d ebate .
a. According to Tourisme Mo ntre al , w hat is th e myth su rro undin g th is pro m in ent feature of the ci ty? [2 ma rks] b. Other sources su ggest th at th e Mo nte re gia n H ills have a n o rig in th at is analogous to th e H aw aiia n isl ands and se amo unts.
i. Identif y th e isl and/se amo unt ch ain th at th e M onte re gia n H ills (in cl udin g Mount R oya l) are d eeme d to b e a p art o f. [1 m ark] ii. Briefly descri bed th e Pl ate T ect onic se ttin g r e quir e d fo r th e island/se amo unt ch ain o rig in . [2 ma rks] iii. Based o n th e isl and/se amo unt in te rp reta tio n fo r th e o rig in o f th e Monte re gia n H ills, d escri be p la te mo tio n a nd a ges in r e la tive te rm s. [4 marks] c. Does Eby’s gra in -si ze d ata , fo r th is fe atu re ’s ig neous ro cks, e nco ura ge o r discourage b elie f in th is myt h? Exp la in . [3 ma rks] d. Eby claims th at a faile d a u la co gen a llo w s fo r an in te rp re ta tio n th at is m ore consistent w it h th e g eolo gica l/ g eoch ronolo gica l e vi dence .
i. Defin e th is te rm and p ro vide a ske tch o f it s Pla te T ect onic co nte xt . [4 marks] ii. In statin g “. .. n ote th e a ppro xima te ly 120° a ngle b etw een th e [Monte re gia n H ills] a nd yo unger [W hit e Mo unta in ] p lu to ns ...” d ra w s our attentio n to th e sp atia l a ppeara nce o f th ese in tr u si ons. B y annota tin g Eby’s Fig ure 1 , a re yo u a ble to co nfirm th e a ngula r r e la tio nsh ip b etw een these se rie s of p lu to ns? [3 ma rks] iii. Is this in te rp reta tio n co nsi st ent w it h th e T ourism e M ontr e al m yth? E xp la in .
[3 ma rks] © L. I. Lumb - Sharing proh ibited. V iolat ors subject to legal and/or academ ic consequences. 3 [Marking: ● 1: 22 marks (+3 bonus) ● 2: 19 marks ● 3: 9 marks ● 4: 15 marks ● 5: 22 marks ● Total: 87 marks] Resources Bodycomb, V., FIELD TRI P 2: T H E IG NEO US, SED IMEN TAR Y AN D M ETA M ORPH IC HISTORY OF MOUNT R OYAL , http://transsexy.geophys.mcg ill. ca /~o livi a/U PE/ Fie ld _tri p s/ tri p 2.h tm l# geolo gy , 2 001.
(Plandowski’s geological map is re fe re nce d in th is re so urce .) Available from: Nelson Eby , Sep 15, 2015 https://www.researchgate.net/publication/281784303_GEOLOGY_AND_PETROLOGY_OF_THE_MONT_ROYAL_PLUT ON_MONTREAL_QUEBEC , DOI: 10.13140/RG.2.1.5022.8884 · © L. I. Lumb - Sharing proh ibited. V iolat ors subject to legal and/or academ ic consequences. 4
