Early Holocene Climate of Southwestern Alberta, Canada, Reconstructed from Lake Sediment Cores

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1997 Early holocene climate of southwestern Alberta, Canada, reconstructed from lake sediment cores

Beierle, Brandon Dennis

Beierle, B. D. (1997). Early holocene climate of southwestern Alberta, Canada, reconstructed from lake sediment cores (Unpublished master's thesis). University of Calgary, Calgary, AB. doi:10.11575/PRISM/13885 http://hdl.handle.net/1880/26787 master thesis

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Early Holoaae Climate of Soutbwmtrn Alkrt., Canada, Reconstructed From Lake Sediment Cores

Brandon Dennis Beierle

A THESIS SUBMITTED TO THE FACULTY OF GRADUATE STUDIES IN PARTIAL FULFlLLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE

DEPARTMENT OF GEOGRAPHY

CALGARY,ALBERTA JANUARY, 1997

0 Brandon Dennis Beierle 1997 National Library Biblioth4que nationale du Canada Acquisitions and Acquisiiions et Bibliographic Se~-ces services bibliographiques 39s warismet 395, rue Wdlington OltawaON KlAW -ON K1AW Canada Canada

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The author retains ownership of the L'auteur conserve la propri6t6 du copyright in his/her thesis. Neither droit d'auteur qui proege sa these. Ni the thesis nor substantial extracts la thbe ni des extraits substantiek de fiom it may be printed or otherwise celle-ci ne doivent &re imprim& ou reproduced with the author's autrement reproduits sans son permission. autorisatin, paiod,dimrSeddtunrtic9yd~pitrtio11~.Pnvi~~~memrchbu id~thiswum~howcv~ram~~'bsdhaeinhvcimprovcd dutiorrof~n811ak&~tbaipecadmQitymQity Sedinmt cores &om 3 gLd.pI-fibd -pine hka indicate that sedimentation in betweea l0,OOO ad 9400 BP, uggdng tht wspadal mdimcnt inaux tcnniruted in responac to inma@ climatic wrrmtb lad aridity which mused alpine gimers to wmpIetdy melt. Clerr water rcsuItiq .#?omt emination of suspended sediment influx allowed Ghc~-f'iingmolluscs to colonize lower Butrll Me, ad greuly inaucd organic productivity in dl three Wrcr through incrrued photosynthesis. Stable oxygen ud arbon isotope marurrmanr on o@c ud cubonate firctions of thcrt cores suggest ninimrl glrdJ ioauenct on subalpine Uu betwea~10,000 ud shortly &a 6734 BP. Additional rsdhnaot corn hm7 clodbash Was in the subalpine, montane MCI foothitls of southwestem Alksu suggest inaarcd warmth and aridity between 10,000 and sometime .fta 6734 BP. An erosional uncodormity Ldicatu that Cuhvright Lake had completely dried out by 6734 BP. Pat Mes in two other lakes also bdiute low wrta levels during the ariy Hdoocllt. The distance between the ullcddonnity ud peat ficies,mdmodanwua~uspsrtposriMt~od~wrtff1.MelowcMgof~ least 6.5 m. Strble omen nlwr from the organic Won of Sibbald Lake become propssivdy hervier rlta 10,000 BP, iadiclting r negative water balance existed for most of thc euty Holoccllc.

iii Acknowiodgm8~ PiIwauld Wa to thrnlrDr. DaJd Sndth Dcputmcrdof~hy,The UniVCISity of Calgary, bbr his @eace, @ante md Upthmqbm the rrrerreh ud-oftbirt&dr. IwauldbliketotMtDr.~Hillrfahisfiidship, critid~~idgaikrrtnildcolrddcnbkhdp. AMitionrltbrdoueowadb~~~ptwi~~~k fidd help, aitid review ud hovr ofgood convaptioa md dcbae. Doug Nethelped me both in the fidd ud with dihmohma oft& concepts her& I wouM dm like to thank rll of my otha fidd assistmts: Mike Getty, Julia Ciccqlione, Duncan Milne, Wff Sdunidtkr ud myone else I myhave forgotten. NdeVddhoen is owed a debt of gmthdt for putting up with my late nights udlongtrips, mdtkpcovidingnrcwahlo~drupponthnnr~thtlut5yan. Fn9y,IwouldliLetotMrypucntrudamilyforrllofdwirhdpud ='Ppo** Sueisotope rnJrses were completed with the genctous support of Dr. HR Kmuy Dcprnment of Physics ud Astronomy, The University of Clguy, and a debt of gntitude is owed to Dr. Kmuse for providing much ddadvice and instruction in prepamtion and intaprrtrtion of ruapkr ud 61.. Nenita Lozrmo, Jam Pontoy md Muir hGhducu are Jlo thrnked for their imnluable assistance in irb methods, sample prepontions 8nd dyses. Fwding for this rrseuch anr provided by m NSERC opating grant to Dr. Smith. Funding for coring, uvlyring and dating Karf Lake was gcncmudy provided by Syncde Clludr, Ltd. Summit Wre wu codwith the fbm5aI assistance of WItnton Nrtiod Park, with special thanks to Chief Superintendent Rob Wan for logistical support. Badnd Watmon Nrtid Pula. ud Krnrnulris Cauntry are rtw thanked for pvidbq coUection pamb fbr coring. Thnla ue dm due to the Deputmcnt of Geography, The University of Calgary, for use of field urd lab equipment, u well as providiig space for core uulysis and stowe. Table of Contents ...... * Approval Page ...11 Abstract ...... 111 Aclrnowiedgments ...... iv ...... Table of Contents ...v List of Figures ...... vlrl Equation List ...... xi .* Glossary of Terms ...... xu I . Introduction...... 1 2. Regional Setting...... 4 3 . Previous Research ...... 9 4. Methods ...... 14 4- 1 Field Site Selection...... 14 4.2 Coring Methods ...... 16 4.2.1 Vibracoring system ...... 16 4.2.2 Reasoner percussion coring system ...... -23 4.3 Laboratory Methods ...... 25 4.3.1 Assumptions ...... 25 4.3.1.1 Sedirnentolo~and WeProductivity ...... 25 4.3.1.2 Macrofossils ...... 26 4.3.1.3 Isotor~~...... 28 4.3 -2 Splitting Core ...... -29 4.3.3 Sieving, Sampling and Logging Core ...... 30 4 .3.4 Tepbra Identification ...... 31 4.3.5 Macrofossil Identification...... 32 4.3-6 Combustion Analyses ...... 33 4.3.7 Stable Isotopic Analyses ...... -33 4.3.7.1 Possible Sources of Error...... 34 4.3.7.2 Carbonate Fraction ...... 35 4.3.7.3 &panic Fraction ...-...... *...-...... *...... 36 4.3.7.3.1 Oxygen ...... 36 4.3.7.3.2 Carbon...... 37 4.3.7.3.3 Hydrogen...... -37 5 . Results ...... -38

5.1.2 hoqpnic sand. silt or clay ...... 39 5.1.3 Organic sand, silt or clay ...... 39 5.1.4 Marl ...... 39 5.1.5 Gyttja- ...... 39 5.1.6 Peat...... 39 5.1.7 Peaty Gyttja ...... 40 5.2 Alpine Lakes ...... -40 5.2.1 Open Basin Lakes ...... -40 5.2.1.l~~blpp...... 40 5.2.1.1.1 W ...... *...... 40 5.2. 1 .1.2 -on ...... 43 5.2.1.2- ...... -...-....*...... *...*...... 45 5.2.1.2.1 Rdts...... 45 s.2.1.2.2 jampmaion *...*...... 50 5.2.1.3-m ...... *...... 51 5.2.1.3.1 W ...... 51 5.2.1.3.2 Wmpmaio11...... 54 5.2.2 CldBasin f es ...... 55 5.2.2.1- ...*...... *...... *...... 55 5.2.2.1.1 Rdt~...... 55 5.2.2.1.2 -on...... 57 S.2.2.2lpbp100LIJIl ...... 58 5.2.2.2.1 Resuhs ...... *...... 58 5.2.2.2.2 Interpretation ...... 58 5.2.2.3- ...... 61 5.2.2.3.1 ...... 62 5 .2.2.3.2Interpdon ...... *...*...... *...... *...*...... *.*...... *...-65 5.3 Foothills Irku ...... 66 5.3.1 Fdaick rlfrc ...... 66 5.3.1.1Replltr ...... 5.3.1.2- ...... 70 5.3.2 Cutwright Wrc ...... 72 5.3.2.1- ...... 72 5.3.2.2lprprprarrinn ...... 76 5.3 -3 Sl'bbJd Lake ...... 76 5.3.3.1- ...... 77 5.3.3.2- ...... 81 6. Didon...,.. 1...... *...... *...... *...... 83 6.1 Alpine Wla ...... 83 6.1.1 OpenBuin Wtes...... 83 6.1.2 ClodBash Lakes ...... -. 89 6.2 Foothillr &ku ...... 91 6.3 Regional md 0lOb.l Correluio as ...... 95 7. Sumnuy ...... 101 8. CorrchuioM ...... 104 9. Rdkalm...... ,., ...... ,...... 105 10 . Appcadix 1 .Wrer with Sub-HoI~~~lltmco& ...... 110 0 B e ...... 110 10.2 Beaver Mines Me...... ,.,, ...... 110 10.2.1 Results ...... 110 10.2.2 htupdon...... 110 10.3 SibbrM Pur (BOB)...... 1 11 10.3.1 hhs...... ,...... 11 I

List of Figures Figure 2.1. Locations of lakes cored for this study (black). cored but not used (Appendix 1 ;green) and lakes fiom other studies summarized in this paper (red). Lakes are numbered in the order in which they appear in the text ...... 5 Figure 2.2. Morphology and topography of the Kananaskis Lake drainage basin ...... 6 Figure 2.3. Morphology and topography of the lower Burstall Lake drainage basin ...... 7 ~igure.24.Morphology and topography of the Lake louise drainage basin ...... 8 Figure 4.1. Vibracoring equipment being transported across a lake by sled ...... 15 Figure 4.2. Ice auger and hole drilled in lake ice in preparation for coring ...... 17 Figure 4.3. Schematic diagram of the vibracoring system used in this study . a) Core couplers. b) Core catcher. c) Winch and d) Winch clamp ...... 19 Figure 4.4. The 7.5 hp Briggs & Stratton gasoline engine used to power the vibrahead .20 Figure 4.5. 3: 1 Pulley reduction system for forcing the core tube into stiff lake sediments. Note that all vectors should be as close to vertical as possible to avoid bending core tube, and that this technique should not be used in water deeper than 3 pipe sxtions (18rn) ...... 22 Figure 4.6. a) SEM micrograph of a specimen of Gyruulis sp. b) SEM micrograph of a specimen of Pisidium sp ...... -.-....-..27 Figure 5.1. Upper Kananaskis Lake. looking south at Mt Lyautey ...... 41 Figure 5.2. Lithostratigraphy. TOC and stable isotope measurements From Upper Kananaskis Lake ...... 42 Figure 5.3. Lower Burstall Lake in the spring, coring site is in the middle left side of the lake ...... 46 Figure 5.4. The con LBSL2, from lower Burstall Lake. Note the radiocarbon date and Marama tephra ...... 47 Figure 5.5. Lithostratigraphy. macrofossils. TOC/TC and oxygen, cerbon and deuterium stable isotope data from lower Burstall Lake ...... 48 Figure 5.6. Lithostratigraphy. macrofossils and TOCTTC of Lake Louise ...... 52 Figure 5.7. Lithostratigraphy. macrofossil and TOC/TC data from Copper Lake. Radiocarbon ages from White and Osbom (1992) ...... 56 Figure 5.8. Lithostratigraphy of Johnson Lake ...... 59 Figure 5.9. Peat and tephra/slope wash interbeds in the post-Mazarna section of JOHNL I. tiom Johnson Lake ...... ,. ..*...... *...... 60

viii

Figure 6.5. Dates from lakes in mountain and foothills areas of Alberta, as well as fiom three lakes in Sweden amnged by sedimentology and age- Blue points indicate that the material dated was taken fiom an inorganic manix, pink fiom organic. Studies using bul t dates were excluded (see discussion for references)...... 96 Figure LO. I . Macrofossils, TOC/TC and 6 13cfiom Altrude Lake ...... -.. .. -.- -.-. - -- -. --- I 14 Equation List Equation I. I The equations used to calculate weight percent TOC, TIC and TC values- Where Nl and Mar represent bum 1 and bum 2, respectively. Mi represents initial weight including the crucible, and M, represents the . weight of the crucible- All results are expressed as percent dry weight... 33 Equation 1.2 The equation for calculating del (6) values relative to a standant Multiplying the result by 100 converts results to the per mil scale (46). 'I' represents the element, 'H' and 'LT represent heavy and-lightisotopic species, respectively-...... --.-..------. ------...-.-....---.-- -- .-.------..-.-.-..-...-.-... 34 =X - Chemial notation for m isotope, where XX h the atomic mass ud X is the dement. Deuterium could be axpressed as 'H, however this is not the convention and it is unully noted 8s D.

Calendar yeus Bt - Notation to tdiate that r &e is presented in actual dadu yeur (365 days), as opposed to less rcnvmc radiometric sales. Radiotubocl yun BP - Noation to difFcrc~ltiatedates fkom Rdiourbon methods hm crlardu dates- This b necmwy kcrue "C vuirtions through geologic time have made this time scale di@tly norrlinar. BP - Ycur More present (1950). unkrr othemise iadiuted, this noution ref- to Niiocubon yeus BP. TbeclhnrtcofthelrtcPkbroocncirchrnaaitalby~npidshifbinboth tcmpmtwe d mpiruion (M-, 11993). Nslr ?be end of the PWoccne the Y~~ctimrtiCiatanlhtb@ttobkhd8bnti0n0fpabrp~ 1,325 ysur (Aky et d.. 1993; hmgmd et J., 1969). Remtt work in the Cuudirn Rodry Manrrinr(RaRmsrd., 199))~thlt1mhlQt~rauhraceUSOCi1td with the Y- Drym may have dr l0.100 BP. Ednum oftha tmbtion of thcY~Dyu~bromDYE,GRSProdGISP?iacorrrtr&nfiornthe Gddice sheet sumat thaf climaic changes fmcn the extreme cold of the Younger hyu to wum~rconditions myhave occutred in as little as 10 yeus, with recent high resolution data tiom the GISP2 ice con su~~gas little as 3 years (Any ct d., 1993; D& D& a d, 1989). Tdonoftht Yourpr Dtyu odd paid .bout 10,000 BP is thought of u the and ofPkistocare ice age dhM+ md the fhul episode in late Pleistoene climue instability (Alley et d., 1993). Srrbk isotope md pdynoIogid studies of lrcuSIrine records 60m nosthem Europe indicrtt the 10,000 BP isochron was a time of rapid wlvmin8 d inaucd precipitation in muine-influenced eons (S. Bjmck, pcrr carnrr, 1995). Wamhg in the early HOWof the North American palooclimrrte record has bemt~thcHyp~AltitbamJorClimrtic~butmrnyofthadrt. supporting arty Holocene wtrmhy in North kncria am dariwd fiom p.leorols ud other low resolution direct proxy data (I(rrlstrom, 1990; Vrrdren, 1989). The pl40ClinUte ncord of the foothills adRocky Mountah has ka, largely badon reconstructions of alpine gkkl activity md the gwmorphic mnrinr of ice dvmca. events lave mom obvious gemnorphic md #dimaauy evidence thn do wum pgiods, consequaaly ~rphoIogiaUy~ncorwtructi01~ tmd to only mrdodd periods (bdanm ud 1979; Ohmmd Luckman, 1988; Rersoner a J., 1994). whik wum paidmy be lumped toaetk as non-glacial intds or missed dtogaha. An additional problem with these records is the poor dating control on thcti~mdduMionoftha~Hoboglewumpai~bothinglriJ.ad prleolinrndogkd records- Isolated ndioorrbon drtu @ommorrincr md glacier foddds u~~lbdJiabdnrmtdkyoadt&modcnr~~8000BP,~dany 1988)wbih~~ur~~~mdhved~ proybslrau#r'tohferchdc~arvuiayofthnr.Byohhhgnew ~OcubOndrtarona~suiteofoonriacousbtwarcnrAlbgyco~6tcsfiom otha-mRcadrkrsdonrPljrr~EdcrSdqll~md~ tcphrocbro-, thc thing of tbe onm&of the ariy Mdosaw amm pgiod can be more pfeciroly~. Pdeoblo~dwork on the early HoIoccllt in Alberta has identified changes in chute hrrd on changes in vliniy, or dirtom or @en asmb1agu (MacDoruld, 1989; Schwega md Hicknun, 1989; Vincc. I986a), but prlynokgy provides 8 ncord only of how plant communith mpnd to clinute change ntha drrn mtuurine rcaul climate change, while diatom md vlhrity data mtd only inm-buinrl changes in wrtu chemistry. Whib these mcthOd010gk uc VrlIUbIe, they .n indirra proxy drt.; rcc4xdin8 in r system which is &ktd by ludrcrpe change, which is in turn aftkted by climrte. By using more direct proxy sources such as suMc isotope analysis of organic ud arbowe Wce rtdimQd3 ad applying principies of rrdimcntology ud

SCQUCI~C~stratigraphy it is powile to reconstnrct the physiographic efEii of climate chmgeonthedrabge~~rir&.Thsougbuchdinaproxyd.ts precipitation klrncq dhmt input lad source, glrcirl dvity ud water table levds mybe deduced. Udin combidon with indirrn pro~rydru such as lake productivity ud tmcrofid adystq as well dotubon dning ud tep)Irochrodogy, thae methods promise to match tb hi@ resolution of Europan lake records wWis miming &om North American litcnfiutcnfiut Global circulrtion models predict -se warming in the nar hture which may be dmkto the wum mod in the arfy Holocene. Becaw present prlcoclimrtic ncorb lack dcicnt detail to cxtnpolate ldsupa change ud actual climatic conditions dwhg the Ho~ocaw,these bl. &t be used to pdctthe posdbk effkcts of global dg.If we are to prepue adequately for fiture climatic change, a thorough what were the pbyliogrpbic ud avbonnartrl atrkts of this wum period in the foothills UdRoclry Moudlhr, Of10uth~Abao Theobj&tivcrofthirhdyrarrbdoan: 1. TouaastbeluuI~~in~lUbertlcuradbytht euiy Holoocne wum mod. 2. To tcconstnrct the hyhIogic response in southwestem Alberta to the dyHolocene wum paid. 3 To Muundd the thin8 md duration of the early Holocene wwm paiod through docubon dating tephtochronology, d mctdltion with other reads.

F igm 2.2. Morphology and topography of the Upper Kananeskis Lake drainage basin. Figurn 2.3. Morphology and mpogmphy of the lower Buntall Lake drainage basin. Figure 2.4. Morphology and topography of the Lake Louise drainage basin. *h~tolaitionhthc~dnmaddoft&Y-Dyutothcwumth oftheeulyH~bubeen~~h~ddeof~unAlkN. ~onthe~ndregiorul~p~tanrthirchulgthrkcn~cdh dittkea ways* Worlr in Afiia (Wiia d, 1993) augpsts rising wrta lev& in qmue to inemad pdpitrtion a! Lake bh@, Kenya, beghhg at l0,OOO BP, bad onevidenceofCOmmrrrri~on~tbbuxlmdj~lakebuin.Asimhrprttan ofWrclevrl~rtthcH~P~bouaduy~inthcYu~~t Penbwla of Mdw (Leyden et 4.. I-), with cook oooditions (3 to 4.PC lower than prrsent dry) pteMiling until after 9000 BP when a wanner climate was established. In contrast, research in m~tdAlberta (Schweger and Hickman, 1989), indicates a warm,dypaiodktmcn9000uul6000BP. OtherworLarhavedsoshownthesrly Holocene to hvc been wum md dy on the Alberta plains md fwttrills. Macdonald (1989) sugeests uidity at Tobogsur Lake, in the BwCreek uer of Alknr, nrrting at l~OOOBPonthebuirofdenttdJphvuppam~linadthcpnscnceofmush vegetrtion in what is toby r 5 m deep lake The diffcrrnca betwem these studies are r reflection of the complexity of climatic systems in Mbrent po~n~hicucu In cwrJ sdngs, brnuod warmth in the early Hoioant Idto inacucd precipitation md humidity born oceanic c~pontion-den a d., 1994); S. Bj- Per& Carnrr, 1995), whik other marine ucu were inundated by cold mdtmtaborn mtmtkg Wmrwinrn ice sbats. In the case of the WofMacico, this resulted in a cod mdtwQter lais floating on top ofhavier dine ocean water (Leyden . 1994). which ded Wlters in the gulf of Mexico and resulted in cooler ternpmtum in rdjacent mrr, u wdl u M inaucd aridity due to lower c~pontion rates fiom cooler ocan water (COHMAP, 1988). Aras under the influam of an anti- cyclonic hi& above the L,u~rentide ice sheet, as existed in Alberta during the dy Holocay were isdated from moist Pacific ahuses by routhaly deflection of the jet stream -den et d., 1994), dtingm deuased amounts of precipitation. in addition to cWcficdb.dr mrchnism, orbital variations place the nrnrma solstice at the 10 perihciioa Wweat 10,400 BP md 8,200 BP, resulting in the grtrtest semcdhy of the bPbbmme\Wpaiod~,1993). ~~wauld~~ ~hrtbaunraarudrmchb~intbwiatar(J~1980). P~workinthcplrinr,~suulRockyMounEliarof~hr been dedout by many worken, with mcthodologim mging fiam large sale .atl photo~hicmapping (Hickm~md Schwelpr, 1993; Rcuoner et 1,1994; Schwqer ud HMnm, 1989; Vmcc, 1986q V~llcq1992) to pdeoml adysb (Kutrtmm, 1988) to Ppkolimndogy rad hke hm dbmt corn (Jackson, 1980; Karhmm, 1988; K.rldom, 1990; Luckman md Oabom 1979; 03ban md Luckman, 1988). The tht two ttcbniquts ue saedy limited in that they are only srprbk of large oocillrtians in climate, and do not yidd a constant record through time. Cross cutting relationships d supaposition dro work to the detriment of these techniques in that younpr events mydestroy the evidence of older ones. Mapping of aubcial deposits and

Mformr CM yidd vay complete rscoMrmdions of put events md climues, but is @n limited by the prrrantion potcntirl of a given bdscap.. Soil mJysis has been used to demonatrate paid of ubility between paiods of bdsqc change, but is not capable of reprodu- hi* molution, ooninuow records of put climrtm. Muy eeku at recotw~cuctingthe Qwtanuy climrte of southwestan Albau hinse upon these two methods (MacDotuld, 1982), dting in climatic chronologies which identi@ only relative changes in put environments. Paidof soil fonnrtion mycomhte to climatic strb'ity, ud monhdc rami~~my conduc to paiodr ofglacial advance, unfortunatelyp this mrdis not contiamus md ill- only ad msmkn of the climatic continuum. Laadmad rtudicr, though limitad by the time dncc Wte follnation. o&r the possibility of hi@-molution, wddrted ppkdoclimrtic teconstructio~~of the timin~ duntion ud physiohhic &iof clhnrte change. ~l0~CdYdued@c~cnhoMUnd ~CCO~N~O~S bl the pl8kS, foothills ad Roelcy Mounuinr of Alknr have become increuirrg common within the lut ten to sfteen yem. Wcihonrld (1982) m&ed dment cores 6om r bog in the Bow Valley, near Mt. Yunulq ud section arpod by the excavation of Wedge Lakep in Kuunultis Country. On the basis ofpollen, cubonate ud gnin size analysis, MacDonJd 11 su~ectrthrt~inthe~vJky~priorto10,40OBP, &by 9395 BP adequate pdogds hd dto Sow roilr UllfOgow to modun conditionrtodhh. Climrte~tow~nrftalO,400BPuntilimmadirtdy p~~Gl(rtrmrCine, w&n it dodinod hdo mod- MOIU 1989). AnJyd8 of cmr @omToboggan Lake (~1~)fficirlnune) wing pdynoIogyVtoul 0-e cubon (TOC), ud arbonue colllant (TIC) Ldicucr that climrte in the mdy Holocene mruiddof~wumthtbrntoday~d,1989).Onthckd,ofthe pmsenceofpollen~thcwetludtrrr~md~~ruldinf~r~thrt Urel~annlo~thninmodgatimcr,udthr~rho~~uw~opato colonintion by these #enera Chenqm&ceue and Ammznhaceoe (cheno-am) are aggr&ve colonizers of newly exposed mudflats and were dso present in the arly HoIoccne of Toboggan Lake. Water levels in Toboggan Lakt were infbrrd to be lower &om appmximatdy 9,500 BP to rhortly &a 8.000 BP (M&DonJd, 1989). Schweger md Hidtmrn (1989) ud Hicltmrn ud Wwepr (1993) sugeest that lakes in the plwof Abatr less than 8 m deep were dry until 7500 BP. Vuvr (1986) summarked adable data bmm pbWres md suggtstcd that climrte was warmer md drier than at present between 9000 ud 4000 BP. Vance (1992) also sugeest fluctuations in lake water levels prior to 6000 BP based on intakdded ddcatio-ked mud and deeper water #dhnans in Chappice lake, southeastern Alkm. Hurir Lake, dso in southwestern Saskatchewan, was investigated by Surchyn (1990)* who suggests wanner md driaclimrtepravrilcd~9l2Omd 7700 BP, whkthethne ofgrates aridity occumed immcdirtdy dkr 7700 BP. Data fhm southwestern Sahtchewur candrte wdl with those &om mtherstenr Saskatchewan, suggesting warn, dry conditions pmddkrwecn9000ud5000BPwchebosisofudimcrrtcacrfiomephcmcnl ponds in hurnmocIry monLw (Klucag 1994). hsthstudies at hke 0'- in Yoho National Park (Rsuoner ud Hickman, 1989) sum that atwtcn 8530 and 2400 BP, minimum @acid activity occurred in the Lake O'Hm region bued on total sedimentdon rates d the o@c lldhlre of lake sedhmts deposited durins this time. Oprbin Wre, which is upstream brom Lake 0'- was dominated by clastic input fiom $rid sources until 7000 BP, when Pinw md Abies pollen dosused to extraplate apparent elevations for each location in this study show that the Watchtower bash site was up to 150 m lower in apparent eldon between 8040 ud 6734 BP, while the Excelsior site was up to 200 m lower bawan 8450 md 6734 BP (Luchnm md Kumey, 1986). Corn fiom r anJl kettle lake in the MJigm Wn ucq dm in Jasper National Pp4 sumest low water levels in the dyHolocene badon a snrll pat Lrya to 7560 +/- 440 BP (Karney ud Luckman, 1987). The uppa ud lowa ends of the pea codof marl, which continues through 6734 BP, to beyond the 3400 BP St. Hdau Y set teph Cores diom Bow and Hector lakes contain TOC records indicating high orgmic sediiion prior to the Brid~eRiver tcph (2332 BP) (taond, 1986), however, the cores did not extend to

and indicate that organic deposition in this lake began prior to 6734 BP and continued until 2700 SP, when clrstic whenmion resumed. Luckman (1988). suggested lyp-sale glad donand increased tree Line elevation in the Co1wnbir Xa Fields amof Jasper Natiod Park occurnd prior to 8230 BP bued on ndiocubon dates bmwood fdabove the niddem treeline at the snout of the ~thbuu~lrdar. Luckman adOhm (1979) sugpest r pre 6800 BP Crowfoot Advance based on the presence of Murmr Tephn on glacial monhs. Ohmmd Luckman (1988) Gnha refine the date of the Crowfoot advance as occurring prior to 9200 BP based on dates of the Hypdt&nnJ wum paid plblirbod dadme. Amir mid Hd(1977) dm note r ~~forthissbdywmwkdcdhedonthmccrital:1)Wnta rcccrria2) Lake dcph ud 3) sating ud loation* wiata rod ltoat to mgeted blar anr aiticJ kcuue the viiwrin# equipment used to obtain core samples for this study weighs in excess of 300 kg and cannot be transported owr opar ground for long disturccssturccsAlthough the equipment is mountd in thedab to heilitua asy pulling ova mow md ice (Fig. 4.1), another imporunthetorhrccaribilityanrtktaninktwwatkrodudtheWa- Steephills or thick bnuh proved cldrrrndy difljcult ud d~gaorwfa towing r rkd. Consequently, only laka into which the vibmcoring equip- could be dely trarwponed were meted for ~0~8- Me depth becune m imporunt cwdddon after reval attempts to core shallow lakes (am) fiilcd. In these uses, only r short record could be obtained kawc the vibncom anr stopped by m impcwtnMe layer of dry. highly compacted (sun- baked?) mud. The uaunpion mde wu that these bpaiodidy dry aut, laving r hrrd pm which could not be pcllctntsd using the viblllcorin~systcm. An rdd'od co~poni~~Iufyhanlc~rrruofchefwthill&wuthtwowl.kashvc the potentid to have bem disturbed by ungulates wading into the lake to wrta themselves and u r mult would contain incomplete or rtntignphially disrupted records. The final aitaion for selecting COMB sites wrs the geognphic loation md setting oftbelake. T&pupocaof~~uto~climrte~eona~odsukmd lakes wen chosen to both maximhe the geographic range covered md sample within the range 8s ewnly as possible.

W& the exception of lower BuntJl Lake, rll Wre sed'urrmt cons in this study were obt.intd using r vibnooring system (Smith, -1992; Smith, in press) which, depending on the buin morphology was configured in revarl di&rrnb ways. Lower Burdl Lake

WU c0fd udne 8 mll~PWaUSkn corin# (Raao~,1986). n# hSOfW corer d the dplepc~llwltrtions of vibncorer used vc dded in the two foUowing sections.

Vibmcarhg works on the principle of liquefhction, whereby vibration induces water-saturated sedhna* to bmcliquded. Liqucaaion occun becurst vibrations incnr# pore fluid prrrurrr, which force individd stdiment gnins apart, d cause 8 loss of baring strength in the sed'umnt. Whcn an dwninrm irrigation pipe is vibnted with a concrete vikruw the rcdimcntr below the lading edge of the pipe ue liquefied, allowing the pipe to didc into the dimact. Only r thin layer of sediment uound the pipe is liquefied, minimizing ddonnrtion, a problem inhermt to other coring systems which utilize padonto drive the core tube into the Wrc bed. Coriq Wru with my coring system is most sdly rccornplished in the winter months when equipment cm be dytnwported acrom the tiozat lake surfhe. Fieen centimctra of lake ice thickness is usdy adequate for coring, unless the ice has mnned

8nd lost barring Srqth. An ice .uga is used to dd8 hok in the hke ice to access the water column (Fig. 4.2).

The MCequipmcllt in the system in t& Deputmcnt of Geography at the Univdty of Cdgpy (FIs.4.3) inchdu a 7 hp Brim md Stnttoa &uobpWCtdd en&e @ig. 4.4). 6tted to tunr cooer&r viklor bed (S- in press). The wior UfitainiacuatomcuurCn~,~u~toa7.62an(3in-)diwcta dwrrinum hiption pip. Aluminum pipe couplar (Fig. 4.3.) uc wed to join multiple sections of pipe if wrta ador dumtdq#& ex- the length of one pipe (62 m). Additioarlpipeu~uthe~~uloarscdintothsantawlwnnadlor viiiatotheWrebd. Whar~pipe~irvhtdwiththtcaacntviintor,it li~csCrthe~~owitmdridaL*otheUe~ottcnundaitrownWCi~.If dditiod might is needed, r pmsik din8 tied Mund the pipe anbe wed as r foothold, allowing r paron to place their fuU weight on the pipe md force it into more resistive sedits* Sditvibrated into the pipe are had in by a core catcher (Fig 4.3 b), consisting of r machined steel body ad teeth made of bnrc shim stack (Smith in pus). As the core is extracted ftwr the We bed, r putiJ vacuum under the core tube places downward pnswc on the core catcher, cloaiqo the teeth ud pmc&g loss of the sample. For lon~crcores (>I0 m), thicker shim nocL ir wed to pmmt the core catcher teah fiom Wing outwud under the weight of dhmt. Initially, are tubes were extracted hm the lake bed using r folw ladda with r mrchincd du- cap in conjunction with a ratchet chain hoist to pull on r loop of boa mooring Line tied in r prusik knot around the core tube. This method hr the disadvantage of p(line the core fiwn the top, which my (although it hu mr happened) pull r pipe out of the pipe caupk, resulting in tha loss of the lower sections of cam, pipe rad couplers. Another drawback ofthis mahod is that in dcepal&es, thcpipes~mrykrhortarthnthchkeisdeep, mdrrlippingp~ lolot q cause the 10s of r pipe slrin8 in to the We dtingin the loss ofthe con,pipe, couplers etc. To fix thew potential werbKllar. a hurddcd winch mounted on a h, which is in turn mounted on rkiq wu developed to extract the con by puliing fiom the bottom up (Fig. 4.3~). Braided steel rimrff able which is rtachcd to the winch is clamped to the bottom core tube 75 cm above the core catcher 4.3d), and can then

Figmrc 4.4. The 73bp B* & !hattom proUr mgbc ud to power tk vibrrbad. lo~d~o11rthedngitt.Corrrwbicbuetokkeptucappedwith3 l/8inch(7.9an)nviliqetukpClQ~avor1&doftbcpipZhddinpl.oa~dua tape* CoM h Mowlakes hr the advantage of requiring less pipe, ud generally leas work thnh deeper ones. Adaptations mde specifidly for circwnnures whm the lake watcrisleshm I8 mdeepindudetheuseofrahortclimbingro# two pulleysandan ice 3craw to build r 3:l pulley ductbn system dnilr to tkmountrinecring z-pulky usd in crrvucc maws (Fig. 4.5). The pScy systun b &red to m ice screw in the ice immsdirtdy beside the hok and crates r 3:l mschuricrl dwntage, allowing host 275 kg of force to be applied downward by m average person, forcing the pipe into the dimem. In boggy uac. or in kt rp@ conditions, the ice mybe strong enough to coreonbut thesudbhyersmay ktoowdctohold~icescrew, allowing it to pull out under tension. mdy,Sunli* hi* the top of the ice screw my warm it enou@~mdttk~icr,bsPuiqetkrcrrwtoplllout.Cllltionmurtk ~~~~intharc~torvoid~auwdbyictscr~brerldngloo~with high vdocity. In ciraMstraar whan Ior dame peat is penetnted, it mydquatdy plug the urn so r core catcher is not ded. In these circumstmcq paKtntion myk substanti@ inaared if r core catcher is not used, with no risk of losing the core. Additional pavtntion mybe obuind by shqmhg the end oftha pipe with a hlc. Vibmcorin~in deep lakes (>35 m) hu previously been probldc for several rswry lugdy becawc of the amount of pipe needed to core in deep water. worn the bottom of the core tube, d is clunped in place, pwsed'i loss. To apply this device, the coupler is unbolted, rpcd myopen and slid to below the joint. When the coupler is Jar of the joint, the upper pipe is tilted rli&tly to open up a space between the two pipes, md the shod blde on the damp is did in. The upper pipe is then did rll the way back into the shovd, ud the damp closed. The upper pipe can then be lowered to hOric0nt.l position md capped. Full details of vibnco~sin lakes ue summuid in Smith (1992; k pw).

4.2.2 Reasmar p~missfonCWI~~ system Beawe of the incccessibility of lower BudLake (5 km hmthe rod to the lake)? r Reasoner peradon corin8 system (Rasona. 1986) was used. The Rerwmr ~oncomirrrimpltw~~an,~&~kkdltboaputcr~lertmy hardware stom It is emtidy li-ght plrrric, ud may be backpwked in to remote !?ite!k Tk buic canftunion ofhibollg system dm of I ninfodPVC core hed, wbich rcrcwr an to 1 3 m of PVC oaanr pipe (Rasonu, 1986). d rddiDioaJpi~of~mykMka~~b~dephof6mAropeis fbtemd to 1& con bud, ud the pipe is lowed into the was. The only hitdon on wrta depth is the amount of rope adabk. The pipe is pounded into the WWbyrdrivg~hPVCpipeWrvitbcit&rrodLI(~~kon&e)or cana&udorppodatbochadr. AddirmcrapieceofPVCirmdownhnriddk ofthedriver, md bderrrrdriUediatbaaprtorllowthamrinrapotok~throu8h the center of driver (Reas~ner, 1986). A lighter wei* rope is rarhrd to the driver, which is lowered slowly down the main rope, until it contru the core head. Once the driver is in position, it is UAed ud dropped repeatedly to &Mncr the core tubes into the Mebed. The core is extracted by pulling on the main rope Usually r z-pulicy must be set up on the Wu ice to amrt the core. Thi, piny -em is mechuriaUy equivalent to the one wed in vi'bflcoring, but uses two ice screws, two pulleys ud the main rope atached to the core had, ud is set up horizontally on the lake ice rurfice. A section of pipe may be pldnext to the hole in the ice to pmmt the rope hmbinding on the edge of the hole. Once extracted, the core is left to fi#ze ovanight, ud a Ratrn trip is made to cut the core into stdl pieces (1.5 m) rad cay it out bmthe site. timitrti~~~of~Rtuoll~~y*cmurthcI~ofawawbichunkulr~ud the defonnrtion of -which an occur. T)uou@ QQerimmtrtion, it wu da~tfvta~tuk~hrtothcUekdmo~thrn6mo&ncrnnotk removed, tesuhing in loss of the core, core head, d possibly r donof rope. This limits the la@ ofcore which can be ~lccdbllyrtcovcfcd using this system. Because ' of the pandine udto drive the core into the lake bed, ~10th~problem is that sediments ue often med down by Eriction with the inside of the core tube, mhing in conid def'onnrtion of luninra (Rgy)ner, pa. Chum.) which make rccunte sampling diScuIt ad may tnnrlocae mraofods or srmctum. Prlearwironmentd intapcrrtionr made on the buis of stdimentology used two criteria to datamins the genesis of the sdhmts in question; 1) the organic content of the sediment and, 2) srmc~crpresent in the sediment. H%ry chic sedimenu arc considered to have rrarltal hmdtha mlirn or fluvial pmarras, during arid conditions in the arc of eulh &porition or wet!w periods in the case of fluvirl deposition. Sechxmts fiom them two mwccs were on the buis of in Mu macrofossil usanbhges which indid water depth md Wonrates. Fluvirl depoitiod conditions were usocbd with deep water brrcd on the assumption that high adimmt.tion rues in r fluvial envitonment would lad to b Wte bash filling to capacity with the wrta tht hitidy truw~ortedthe dmmt. Thercfbte, s4dimcrrts deposited in Wow water wnlitioar (dative to the apcicity of the hke basin) wac identified u beingofdoliurorigin. Stluccurrrwithincluticredimanrwaehdtointc~pret gumis. Orgrnic sedimentatioa in lrkm is intapretd to hrve mtd &om autochtho~)~~ 'ntnbuinrl) o@c productivity. In dl cws, the onset of organic SedjlMlltrtion h thought to hm madtal &om decmdaupaded sediment Idin Uewaters; whaeby dectud nabidity kcmad the Seahi depth, dowing incmd photosynthesis md therefore bad blre productivity. Organic vdiman results hnn the d- deposition of thc rrmrinr of photoynt&tic organisms. In the three glacier-fed lakes in this study, the hiatus in duic sedimauton is Mito indicate the absence of glacial ice in the aebasin occupied by the lake on the basis of the assumption that 4.3-1.z Macm- Muro~~ursd*~lPIlCllfiJimcrpntrti011werephnuily ~tomdhuoradclucorl.~mnlotbaypgwae~inirduedcua udue~~in~~~~)pCirteI~~an~.OdyebucorlgatathnS00 rnicrwrwuwuntd, dir~piavrilyumindicrSorfbrlodfo~h~(~~ CW????). Fmrtivitymdasspro~toaWrair~indiCItiveofthrre conditions: I) adequate fbel supply, 2) dry condoionswhich allowed &el to be cornbusted dilyand 3) r source of ignition. Of main interest to this study is the implication of dry condition4 which are used in wnjundon with scdimentuy and other autochthonous indicators to irrtcr pllooclinvtic Cdnditions. MoUusc macrofods sieved fiom lake &hunts were idmtified to grms level, ud usad to infa prlw wrditions in the exact coring location based on the ccologicJ niches of each genus identified. For the paposes of this study, only two ganen of mollusc were important: 1) Gutropod. 4-60) md 2) Pdcypod. (Fig. 4.6b). Gastropod molluscs (Runshorn mads) are, physiologiatly, lung breathing (pulmonate), ad fdby on suheqmt Md semi-mbmeqmt .purtic pb. Pdccypad moUuw (Pea duns) w giU brathing d fdthou& filtration of organic particles &om lake waters. Badon thue physiological the prrrcnee or absence of either of thue 8- can be weti to Ma!e conditions in the lake. Ihc presence of gastropod molluscs is infdto be indicative of Wowwater, possiibly littoral conditions with lbundrnt mrrophyte populations. The presence of pdccypodr is intetpreted to indicate Usconditions where there is adequate mgadc mrtcriai suspend~d in the nta and no impdimmt to eitha ~i8or reapintion. Conditions which could impede these pracar#r we a lack of dissolved oxygen, which would ledto uphylciuioq or the pmamof 1-e U~KWII~Uof aupendcd dit,which would rbnde both the f* structure md gill, ofpdecypod duscs. Figure 4.6. a) SEM micmgmph of r sptcircm of Gymdis sg. b)!SEM mkmgmph of aspecimofUsM~lg. GJmaQQM Stable isotope umsmmmU art utilid to mcrurr the degree to which GnYvOnmcntJ idlmum-m of vuioua irotopea of carrin el-. Is~tope~intbir*uby~aaC,OdYwitbclrbonb~bothmrrs13 ud 12,o~hrviagnur16mdl8,d~hviagcaur1md2(Jso~tors

chaium) isotopes. Each daneat u dkbd by 8 digi act of u&od vlri.bkr, md u stab comb'i wrga of w or more dewatr my allow complex mtmctioar to be decoupled md datal b.cL to c&mrtic or environmental change. Oxygen has Judally been used to mc~sumthevolume of global water which is trapped in continental ice masses, wherebythe oceans me assumed to be r fcsc~oirofacertain isotopic do,with ray net nnod of one spier of isotope (to storage in wntinentaf ice mwes) chmgbg tk do(e.g. D8nsg88rd, 1985; Alley, 1993). The delgee of isotopic fhctionation caused by evaporation is fiurtion of the tunpaatwe at which the evaporation took place, then ti,^^ the pdpitation rrsulting fmm this evaporation desr signatureofthetanparaueatwfdchitanpomtal,as wdl uthetunpcnture at whichit rr-condcnrcd (Fane, 1986; Fritz .ad Fontes, 1980). By muswing the oxygen isotope composition of ice acmdated ir hgt ice sh&Ss, it has been Jso been po~bleto reconstruct 'the other ridc of the coin', ud a~uurrthc isotopic composition of the portion of wua mnodborn the oceanic ruewok Oxysm isotopes were usui in tbis study with the intention of mevu- the imtopic cornpodtion of We umtera rr recorded in rutOChfhOnous o-c matter- avmgc mctdcprecipitation values bve nmrincd relatively constant throu* the- H~OCCIIC, excess cv~pontionadd be apected to ause lake water values become hervier (Fuut, 1986). Mumiaotopcr can k wed for ascntirlly the clmt purpose as oxygen (Fame, 1986; Fritz md Font- 1980). ~WCVCT,in uas whae urbollrte bedrock ud gtrdrl tilts are pcrcnt, omen values may be diluted by 'old oxygen' hmthe bedrock, CUI* equilibration with poko ocan values Mha than cantanponneous lake values. Because hydrogen is abmt &om cubonate melts, the use of deuterium stable irotope meuwcmtnts rhould be able to eiiminrte the 'noise' eom bedrock influences. 29

Cubon stable irotope dysiswu conducted in M attempt to diflienntirte otgrnic

Becurse of the high wata coin most k sedimmts d the inelasticity of duminwn, the corn cannot be fb#n or the resulting arpuuion of sediment may cause atwion out the ads of the core tube or splitting of the awe tube dong the sides. The potential lo= of dment is problamrtic. apacirlly if r core has been at into multiple pi-. However, the intd defiodon auwd by fiazing is a hr worse pmbtem bcuurc whole bab may be displaced by tau of canhnarrr u the core &ucr in towards the mid&. Bcaure conventiod diamond rock saw tachnologies cannot be uad on unfiozen sediments m rhcnutive method of splittin8 core hd to be developed. Rior to cuthg, oom are Wedon both sides, .ad orientation mows are dnwn dong the length of the tube. The con is then plwd in r jig mde of thee 2x4 boards, which keeps the core tube stationary md provider guidance for cutting. A SkiN saw with r mwnry or steel @ding disc is wtd to Nke r cut dong the length of the tube (Smith, in pccr). The core is rotated 1W ml the cut is repeated. A shup knife is used to an across the apr at either end, ud is then dnwn down the cuts to split the core into two picar. Ahhough the Me blade may wader duw cutting resulting in uneven halves of core, the rltdveof. pirno wire hu the didvmtqe of catchins on the bw lefk don8 the sides of the pipe by the cutting procar. Care must be taken to stop cuttine at ud cut Mund my tody branches or otba large itaM which may othawise be dragged through the ha d udyartroyjlcc~ltstratigraphy. On# the con is split into hlveq each half is double wrapped in plastic stretch wrap to pment desiccation which drsieving difticuh ud my bias stable isotope ~rrmpkanrcomp~andrd~tkupperrieve,w)richmrtben removed md the amtam cdogwd. Any spccimau too d for immahte idddmwere phd in gbr vials fbr later aunrinaion under a microscope. Abcmfods selected Eot AMS ndiocubon duing were Jump hurdled with twccscn, ud kept in dWkd wua in a dedglur vial until submitted for uulysis. After the uppa sieve M been catalogued, the lower sieve was inspected for clastic residue (6ne to dumd), ud any smaller mraofossils which had fUen thmugh the upper sien C.e. chphyte oogonir). Chudputicles fdin the lower sieve, if pment, mrr dytoo ntlnaau to icwifjr ad count with 8camcy. Chmphyteoogo~daotmdedto bevsynmvmurcindwmercconkdbucdsimplyon pnraa or rbwacc. u were C'w. Stems or am~atiom.Mdhue mraofod8 were~d~bygrur,arto~lsvawberepoaibkU&SSvirl8 ~0~mrcrofoodswaclrbd~hhddibkLJrwithcorruddeph~. ~~Cdmdn~ccoh8d~~ae~0n8pr~a~mrchine qmRulcedin 10antae~IsmdLid~thewretubc~~,prscam, 1994). Inthiswiy, ~dmwu~~ontotheprpa~~trpe.

were mdc for dl intends sicvcd, md listed on the tape by object found, number, and whether a sunpk was retinal for fiutha uulysis. A zero was entered where no ~ucrofodswere fd. Data &om the adding mrhine tapes were then entered into a spmd sheet, with sunpies for chemical adysa bein8 lo* in mn 10 an intends 0.e. 10,20,30,40 ...), md sieving samples logged in odd 10 an intcnnlr @e. 5, 10. 15, 2L)- Teplrrrorothawdimentuy~~whileri~thecomwacsunpld udloggalontheprpa~mrddnctlpe.Lithostmtignphic6ubornthetapesw~ diratty transposed into CordDRAMP at 1:l defor rcnvry to produa lithostntignphic logs, with irm proportiod reduction of the image to th on a page.

4.3.4 Tephn ldendilSC8~

Any suspected tcphns cllcow~jccddin r core were sunpied ud lamed. A d sub3unpIe was clCU14d in hot HCL, .ad mounted in Cmd. Bdsm on r petrographic slide. Pdrognphic iderrtificrtion of tcph was bucd on the presence of glass shards, which go dnct uada crosrcd poluiting fitten. If glrrs shards were pttscllt, thcir m~rpholo~yud optid mimnlogy was compared to ref- sunplcs using the criteria outlined by Reasoner ud Hsrly (1986). While glass durd morphology itself is not a highly accurate ma~of teph identification, suspected identities myofken be confinnad by d*s of the stratigraphic position ud thickness ofthe tqhn horizon. Four tepb ve pracnt in the study am:Glacier Pak, W u 11,300 BP (Meluin~err d., 1984); 32 dated at 6734 BP (HSa et d,-itled, 1996); St. HkWsY. dated at 3600 BP (Ldmm et d.. 1986); md Bd&pRiver, dadat 2332 BP (Leo- 1995).

could uurlly be idcntified as belonging to atha tarrnrirl or aquatic uxr bucd on cellular structure. Aqdc phtmrteriJ wu not uPcd for diocarbon dating to avoid old cubon amr(AhcDonrld at d., 1987).

Moflusc m~m,foSd~were idantifid using either 8 key (CIuke, 1981). or thmugh conruhrtion with Dr. L.V. HiJls, of the DepMmat of Gadow ud Geophysics. Spshms were idmtifid to the pnau levd, ud wen used primuily as m environmental indicator based on genur Idtraits of fftding md respintion, therefore more complete identification wu umcesmy. TaraseiJ plat rm~~fbssilswere idmtided using sevd keys to modem plants (MacKinnon et d., 1992; PaClidcr ud PGCrides, 1992; Wldtnay, 1985). Where possible, rccognimbte components of r plant were idamtihi to the 8-s Id. TarrariJ plrnt rrrminr were ~~ fhm 4dcplmt rrmrinr by cdlulu structure (M. Gdty, ps.c~arnnr. 1995), or by morphologid churcteristics whae possible. Seeds were identitid by Dr. L.V. Hills. ChreorlLcd nmrhu wae identified by the texture of the spcdmen-

Total oqanic md inorganic carbon wen measured by cornburtion in r finace at 550T md lOWC, mpdvdy(Bmgtsson ud Enull, 1986). and calculation of mass loss weighing the CNQ~subsequent ddbe pdbnned on multiple srmpks

below mamumble levds. Masu-rtr were logged on datashats, which wac

Spmddmt ulEu).lions for weight parcent detcnnjllltiom wae performed as

Quatiom 4.1 'Re tqutiou wed to c8kPlrte wdgt percent TOC, TIC and TC vdaa. WLcrr Mw and Mu rcpmemt barn 1 udbum 2, ~~pedvdy. lV& repmenta initid weight iaduding the db&, and repccwntr the weight of the crud& rcrdts are uprewed 8# percent dry weight %TOC = (Ah1-(Mi - Mm))l (Mi - Mi) 100 %TIC=(Mb2- Mbl)l(Mi- Mcr)*lOO %TC= %TOC+%TIC

Stable isotope mdyses wme pdormed only on conr which rppared to contain m dntanipted .rdimcntuy record, free brom unconfbnnitiu or rppucot sediment dispkmmts. Ddta (8) "0, U~ ud HD mewmmm were pcrfonned on organic muter bmUppa Kuunrskis Lake, lower Burstdl Me, SiWpld Lake, md Frederick

Wewere Jlo mde. Organic carbon isotope mcrarremcnts were conducted in 10 an (Stradrrd Man 0- Wlta). Became aaithcr of these rtrndudr m commonly milrbk, V-PDB md V-SMOW rcrkr ~WWb ref- es cbnJltalbythe~oMIAtadc~~,inViAurrrir,hsnccthcV

Equatioa 4.2 The quatho for crkuhting dd (6) vduu rrlrtive to 8 standard. MrWplybg the result by 1000 converts rcrrlta to the per mil #.k (w.). $1' rcprrrcllts tbc tkmeot, 'H* and 'L' repmen! bavy and

~Possibk,Sourwsnt&mc As in dl dps,thae is conridarble potentid for error when ~CQ~LI~Wstable isotopes. Daily d'bntioli ofthe IMSS sptmrneters used in oxygen ud arbon uulyres indicates chttheirprshioais~.2 %, and< 1.5 JC with thedeuteriummu:)rinc. Given thtmo~oftha~ri~&rcautio1~indwnrbki~0toptdrahr~~d thercamrtanr,mur~m~~~ondoarmtscantokafictor.Sincedl smpla were prrpurd ud uulyrad in radom order, systematic aron were unlilrdy to be inboduced. Panod communications with other worken (Krislinimurthy, ppars Canrm., 1996) have suggmed tht bulk-owe mta~urementsof danerium isotopes can oAen be rffied by waters of hydration in &yr, ud unless o@c matter is w-ed fiom clutic muaiJ there may be contmkmion &om these sources Because the deuterium isotope drt. pmtdhae ofken fluchutar dally, md doas not rhow changes sympathetic to other isotopes, this drtr must k regarded as questionable md deuterium data presented here will only be described md not used in interpretations at this 4.3.7.2 Fmdbn AnJyris of the arbonate haion of Uercdimats was crrricd out on 20 mg ovcn-drid ~~bsunpIcs.Erh runpk wu pMin r, y-tube rppurau with pure phosphoric atid -41, whae the sample sat in one fork dthe acid in the other- Tht y-tube was eVICUlted to rpproximrtdy SO microns of mrary (p Hg) and sealed. The tube wrr then tilted, allowing the rid to nrct with the sample materid. The samples were left to react fot 12 burr, &a which C& evolved dur* the Wonwas nlased into m emmated emironmart md froten with liquid nitrogen. The system wu evacuated again to ranow noddlegwr. the liquid nitragen was removed md a dry ice ad Jcobl mixture ptin its ph. By keeping the system hzen with dry ice and dcohd, water is kept bzen while C& is dowed to cvlponteCA glur tube connected to the system wu hzcn in Liquid nitro~en, the C& p in the glus tube. The Isot~~~mtuwanen~ofoxygeqarboa~~mrykmdeono~c mrtta, though each dcmau rc~oircrclifkmt prrpuuion techniques. Samples for .U three masutemerrw amc pntr;trted with 6 N phosphoric acid for 24 hours, foUowaf by two cycles of catrifir@g ud washing to remove the scid. Pretreated samples were then fieuedricd for 5 drys to mmve dl water. Freeze drying was utilised inned of oven drying to avoid ngow opeudc reins which may have been prrrcnt in the samples.

4.3.7.3.1 Oxygen Oxygen is extracted from organic matter using the nickel pyrolysis method (Edwuds a al., 1994). Nickd bombs were filled with between 100 and 400 milligram of

fieemdried sample, ded with 8 llickd dirc in a nitrogen abnosphere to avoid contuninrtion with atmospheric oxygen ud baked at 105O.C for 25 minutes. A gCllCtJitdd chanicd fonnuL hr oqpk rmtariJ may be written u GOBHIr thercfm wbcn organic mataid is hatdin a ded, oxygen ba envitonma~t,oxidation of or@c cubon occun with oxyecn hrn the organic matter. Hydrogen relased in the -on cm dambdy thgh the nickd 4sof the bombs, while the larger CO md C@ moldes cannot pass through the cryrrJline lattice of the nickel. In a complete reaction, dl hydrogen hu diffused brom the bomb, laving CO ud CO, gma. An incomplhte ruction i8 hdicad by the presence of water in thc sample .Rcr baking, which ~thtJIhydros~didnot~outofthebanbudum~oq~iraillbowdin Wef. After baking, each bomb was plwd in m eedbrass tube, the nickel disc dngthe bomb was punctured, and the vmpk gasses were released into a heated glass coil under hi@ vacuum. The sample wu held in the glass coil for 5 minutes, where nickel Carbon isotope rnrlyris is the simplest operation of any detailed here because of the complete computer control system driving the mrss spectrometer md peripknl devices. Sdmounts (50 mg) of rwpk were placed in smJl tin cups, which wae folded uowd the vlnpk ud placed in one dot of a 50 place mgazb connected to 1 bmcc. Samples we budin the rurnrt in r stream of plrified oxygen at 850.C to fonn C& gas, which was conducted into r mass spectrometer whac mcwmmts were made by computer ud output to the attachd printer.

Rcp.ntion for hydrogen isotope adysis requires the combustion of sample in m tVlCUIted glw tube in the parcnce of cuptic oxide (CuO). 100 mg ofvmple is waghed into (1 glass tube dong with 2 g ofcupric oxide. Care must be taken not to ustoo much sample or the rrrulting gases evolved mycaw the gluc tube to explode. The tube is eedUd cut .nl ddwith r blow torch. The dedtubes are baked for 12 houn at 55=, wfiiJl oMithe sample using oxygen fiom both the aupric oxide and the orpnic matter. The products of this donm water (Ha),cubon dioxide (Ca), cubon molloxide (CO), coppa (Cu) rad copper oxides (CuO ud Cus). The glur tubes are than broken into m enautcd systan, where the water is hzen with r dry ice ud alcohd mixaVq ud the runahin8 gurcs are pimped way. The dty ice ad alcohol mixture is taken awry, ud wed to ti&zc the end of r glass tube filled with 2 g of elemental zinc. The @ass tube is thm cut ud rakd with a blow torch. The zinc in the tube reacts with the water to fonn zinc oxide and molecular hydrogen. The tube is then broken into r mass spectrometer, whe the hydrogen gu is raJyled tbr its isotopic compo8itk.

5.1 Fades m8c*dkn Fivcbcisrdaoriptiomhrvcbrpplkdto~~~adintbirra~dy~ on dhmt tamue, dimentolow, cubon coatca ud p&nt ~fossils. Dirtincriwtnvdeue~routopovidc~onsbetweenodytho~~~ chmcterigia which are significant to tba rrlplmcnu witbin this study. Subdividing beyond this led was avoided in orda to limit aa~eousinfomation, Jthough more detailed descriptions of hder in indiviu corn will be provided if occcssrry. The following sections daril the critcrir used to usip uch Bcie- It is important to note that whik .U Meshave gdcimplications, the exact cirarmstu1ct3unda which they form (i.e. climrtidly-forced, gwmorphologiully-forced dc.) mry wry.

5. 1.2 Inwgatak sad, adt or day Tbir bcicr is ddbd u luninrtad or massive mad, silt. or day. Ocusionrl pebble-- cluu mybe present, but ue uwmd to be ice-rafted. The source of the sediment myk eolian, or flu*.

5.1.3 01p8nksend, JnlYorday

This ficicr is de(ined rr king rud, silt or day, with laminated or massive structure, ud antlining 8 snull amount of organic urban (more thn background levels, Put consistr of mndecompocd fibrous plant material with low ckstic sediment content. Peat is mmal to occur aJy in Mowwater (elm), where emergent dsemi- emergat plants can grow. It ir dm urumtd that the peat is growing in contact with the Webed, udirnotflortbrs.

5.1.7 m&GyQb P~~aisdcb#duurint~~thcPl~rad~aMa.Itis ddhdU COn~88 denidant Mounr of &kour mrtu(*A), but with 8 ItUWk of orpic mud. Peaty ayttja is uaully massively structured, and my contain mollusc mrctofods. w Ulmc-bsa Upper Kumukh Lake is a luge, glacier-fd h&, which lies in the rubalpine of Itrnurulds Country at m devation of 1740 m a.s.1. (Fig. 2.1, 2.2). At its deepest, the lake is in excess of 50 but has been mdby 10 m during thc summer months as a dtof 8 hy&oelCCtric dun An 1I m cac (UKANLI)was attracted &om r depth of 48 m in the distalmost of two basins (Fig 5.1). Afk splitting the corn it was discovered that the Holocene record wu contained entidy within the top 2 m of core. Mer sieving the

lower pottion 0thcare ud find@ no mraofods, it was decided that only the upper 2 m of core would be mdymd lad pmentd, in order to reduce lab costs md time (Rg. 5.2).

5.2- 1. 1.1 Results The .rdirnmtoIogy of UKANLl contains fbur hder (Fig- 5.2). The lower 55 an of core consists brgdsandy dt with occuiond thin wd interbeds- Sieving yielded ocariodhpso~whieJlwara~u&on~buisofthehct~thywae found in ochawir fine grainal (sandy dlt) Wu. At 55 an, an abrupt ad

Upper Kananaskis Lake

4B CI t

Figure 5.2. Lithoatrrwphy, TOC adstable botope masumentr from Upper buomkia Lake. coafonnrbk contact between the uadatyine vady silt and Md nvrloccuraFrom 55 to 65 an,1&~m~ofbPdcdmrl,vhichamt8insno~~ordrapsto~~At 65un,themrlrkuptydungut0Mcliva~r,wbiobcoatinvrt094an,amaCitia insetnrptalbyr2cmthickbadof~tephra.Frocn%canto thttopoftkcaa (200 an), there is r pdationrl him Gbrngc from gyttja to inotsrrjc siit. The post- lbhzam eondthe cum is mrdy ad coataim no rrnQOfissiJr. TOCduumg. 5.2) bamathekw ofthecored 50 an m below 7 96. Fmm60to70~vrLwrrhcto21~~~17%untJ160cn,~thty d~to9%udrrrmiaklow12%totbrtopoft&corr(2Wcn). ~kl'bdues masaued fiam organic muter (Fig. 5.2) am 14.6 % af 0 cm, but rise to 18.2 fC by 20 cm. From 20 to 40 an, dues dacline to 15.6 %, then rise to 16.8 SC at 60 an. Values decrruc by 5% 60 ud 100 an, then rrnvin constant at -12 % to I20 cm. Vdues increw to 17.6 % tt 140 can, then decnue rhuply to 6.9 % at 160 cm kmsbgagain to 19.4% at 18Oun. the topmost sample. Cubon rtlbk isotope data of the organic firction of scdimmt f'iom UKANLl (Fig 5.2) ny dc9yover the length of the core. n#re is r gsnarl tdtowards lighter dues &om -26.2 % at 20 cm to -33 L at 90 cm. From 90 an to the top of the con, dues vary in 30 an period flucturtions of about 3 L. These values myhvc been altered by the bet that the samples used were air drkd prior to mJys# where samples hmother corn were pmoarrcd wa md ikmhied. Deuterium Iubk isotope nkKI ny wide ktwcar -23 ud -266 k (Fig. 5.2). pahpsduetothe~oIlddporribilityCoroo~on.VJwrinauctiom- 266% rt thchu~ftb~to -49% at 8Out1, dtcrushgto -238 %a between SO ud 120 an, Mowed by m incnrcc to -23 k rt 160 un, the uppennos sample in this sties.

5.2.1.1-2 inteipretation On the bosir of cornhion bawem the inorganic rudy silt to mul hdts change ad ndiocubon data fiom bum BdLake (this paper), Crowfoot Lake (Reasoner ct d.. 1994). ud Me 0'- (Reuonar ud Hickmur, 1989). the record fiom Upper Kuunulrir Ute at& through the entire Holoana. 44 Scdhncnu60mthtlowa55cmofUKANLl ~mlilcdy~~ uulYauaguhylr~on.Atthetammaam oftbeYoungerDyu,8trbwt 10,000 BP @uueurd a 4.. 1989; Reucmer et rl., 1994), a rhup, COI&XI&I~ ECI change to marl suggest8 that drctic cadhrunt supply to tbe Wn cewd u thu time. Sieving of this intend yiddtd m drcanw @mi aoDionJ lag, oonsequmtly chirhpthder~dognotiadiataa~m~o~BaaueUppar KuunuldrWrc~MluEch/bystdJ#~rea,a~ducti~ninaedimentsupply wrlikdyauredbythetamrartloo. ofgkid raawPa input (Fig 2.2). 'Lh tamidon of thir input pobrMy indiatcs cocapbte cbbtion ofthe glreiar the Wu, resulting from rapid climuic wundng and incnued aridity. Based on comlations to other similar lrauaine records, this ablation rppcrn to hvc been complete by about 10,000 BP. Clutic salimmt influx in the bprJ section of the core ends ud is replacat by r mul Mes at 55 an. Inaeu+d o@c arbon content and Jlmsa in oqgcrr isotope nluu sugeest that the Wr of gl.ciJ adbnant influx led to inmad water duity, which allowed indphotosynthaic productivity md kihted the prrcipitation of mul through photosynthetic rqintiotl. It is also poorie that based uidity caused evaporative conditions in the Wre. auiching lake waters in dissolved solids ud aiding in the precipitation o€C.CQ. Oxygen isotope nkKs churp at this intend in response to dissolved CQ in the Wte equilibrating with difkm oxygen raravoin. As cabcue glrirl sediment influx w ~BursteiW~ Lowar Bunt.U Lake (F8. 5.3), at 1980 m ~s.1.in the subalpine urn (Fis 2.1, 2.3), is fbd host arckuvdy by the Robatron Glacier. A 2.8 m paaurion core, LBSL2 @is. 5.4), wutrlrsnfiom 8 mwrtachpctS aarthemiddltofthe Wrc Lowa BunuU Wre is diMEmoot (dative to the m)of three Urn in the Bunull Pass UQ. Figure 5.3. Lower Barsbll Wrc im tk spriog, cohg site b in the middle kll: dde of tbbke.

W. until 270 an, which is the upparmost mmple in this SCtjes. Cubon stable isotope data (Fig- 5.5) from organic matter ny bemeen -25 d - 33%. Fmmthabucofthecorr.VrLKl~rr-26)C,dropto-29%~lOctn,thcn climb to -27 W, at 20 an. From 20 to 80 dues undergo a more or less steady decline to-32%. &tmar80ud 140~n,vJwrrrmrinnLtivayconrtunbetween3Oud32

%. An increase to -26 WI occurs at 150 can, followed by (I draeur to 33 %O at 160. This sawtooth pman of fluawing nlwr continuts to the top of the core, with values ranging ktwan -32 d -26 % over r paid of about 30 an. Deuterium dkisotope 61. (Fig. 5.5) mde on organic matter born LBSL2 do notvly~w~uthorchUKANLl,butmutrtink~du~onthe buisoftheypllnenumdeinthemahodrsection. Vduuathebrreofthcoomrrr- 210 %, but clitnb to 60 WI rt 40 an. The sunplt fiom 60 an did not yidd enough hydrogen to macurr. The next 8 D mgaremcnt, at 80 can, is -144 %, rising to -56 %D at 100 cm,then declining again to -122 k at 120 an. Samples 140, 160 and 180 were dm too sr~Uto uvlyra. The musured vJut at 220 cm is -28 %, which drops to -61 % at 5.2.1 -2.2 Interpretation Bued on an AMS ndiocubdn date hrn the 49 cm intend of lower Burstdl Lake, ud cod8ti0~to Cmwfoot Lake (Rcuoner et d., 1994), ud meO'h (Raroner ud Hickman, 1989). the recod Eiom Iowa BdLake Jso rpyu the emin Holooau. Scdhmts ffom the lowa 47 cm of LBSLI, thedore, probably represent d~mdYoungerDyu~011.Anrkupfidachmgetomulat47an indicates duddutic rdimcnt influx, nd kcuur no lag deposits were fdwhile sieving this section, it is ammd to be nanaosiod. This transition is limited in age to errlies thur 9180 +I- 60 BP by an AMS radiocubon date born 2 an above the contact. Because lower Buntrll Weis fd Jmost entirdy by the Robauan Glrrcier, cdonof clutic dimat input to the lake indicates that the Roknron Glrcier hdentinly melted prior to 9180 BP, probably at abut 10,000 BP (Fig. 2.3). This dti~was like due to npid &matic w8rming d inaused aridity which au#d the glacier to mter 8 negative mru klrncc until the ice bd completeIy mdted. The donof CWCsediment idux is dadby the deporition of r mul hdcr between 47 ud 57 an, in which orec urbon content rapidly increurtr, oxygen isotope values decline ud Pisidurn q. pdecypocb first colonize the lake. k cldc dllll~ntinput declined, hcdwater clarity allowed incrrwd macmphyte growth, causing both the precipitation of mul and increased TOC values, while allowing gill breathing. filter fdgbivalve moUuscs to hmbedrock to atmorphaic at about l0,OOO BP, mmhing in cquilibriwn with the

5.2.1.3 mm Wrc Louise is a deep (>SO m), glad mdtwrtcr-kl Ue, 1- in the subalpine at 1740 mrs.l., in the mrin ranger ofthe CMdirnRocky Mount.bu (Fig. 2.1, 2.4). Lake Loui~irftd~dybythcVcto~~er,witbulrnnrrlinpnr~m~wdtud mhfU. A9 rn long core (LLl) wu taken in 50 m ofwrta, in the didend of the lake. Isotope mcuvcm~nrrwac not mdc on U1 due to the lack of organic m~erirlin the middle ud late Hdaccm donsof the are.

5.2.1.3.1 Reub The 10~st300 an of Ul conrirrr of dicton, nrde of putidly sand, silt and clay mrtrbt-suppotted andu, striated Jurr to 6 cm I-axis la@ @g. 5.6). From 300 to 400 cm, the core coadsu of inorganic, ChrotiuUy bedded, chy, silt and sand with occasionrJ pcbbk-sized Jutr. Skvin# d runpling for d#lliul rnrlyres was began at Lake Louise

I I i I I I 1 I f 1

Clay-silt I Diamicton i Tephra j 1

-- 1 2 3 4 S 5 10152025 10 20 30 grainJ100 cc hrgt/lOO cc W%

Figure 3.6. Lithostratigraphy, macroforils and TOC/TC of Lake buk 53 400 an, with the aWhhmt of more dbnn dmentahn indicative of lower energy deporitionJ~dthwfe&cingtbt~of~~sition. Ssdbnanrr~400ud510ancaajtdmrdvay~~rilt~rady silt, wbioh wy btrbidiy bws mdt@ hnhigh dbmtaion hma ~VictorirG&cierordumpinOfiomt&~o€theka.At41505 a coUectjonofd(~1an)Dyzscp.lad Abwrp.lolvsrwaflb~~vffCdfromtheco~. Conansntiona ofcouw suul ud pdapeak be6mn 480 ud 510 cm, with dues ~~l.Sto5.SgdnJlOOoc.~nh#rJlopeakinthbM,~ vrlua of27.7 -100 cc. At 510 the iaorprdc dlt rkuphl changes to dvebrown which consinucr to 545 an. Sieviq this contact yielded abund~t chafed fi.lyaenu (5.5 fhgmcnts(l00 oc). as wdl 8s &nnules (5.5 graindl00 cc). Thc gyttja is intempted between 521 and 528 em by hhum teph At 545 an, wa abruptly *a back to inorganic silt, which continues to the top of the core (900 an). This upper hdes ia interrupted by the 1 an thick Bridge River tephn at 715 a. ChucorlcontcatincrrrvrknncnJ7Od78Ocm,withvrl~~~0.6tnd 6.1 -100 cc, to 27.7 Ihen#nr/100 cc at 790 an. Slnd ud gmvd Pprticlcs occur rpondially throughout the post-bhzum donof the core, with a pdc in rud of 2.7 gninzll00 cc ktwcan 860 and 880 cm. TOC values TI%.5.6) ut co~cnflylow throu@mut the core, rrmrining below 3% with the exception ofthe 510 to 540 an intend, where they peak at 14 %, cone3ponding to the hda. Tdcubon (TC) dues are dso nlrtiwly constant, ~rbo~t15~ktancn400d470~rftawhicbtheydeaerceto7 paan at 510 an in the gyttl-I Bdcr. TC nluer incmw to 18 94 at St0 cm, deck againto lO%rt54O,thminCrrUtto 19paccntat560an. TCvdutsr~lbove18 % until 780 an, where they drop to 11 %, rernrinin8 at that lewl until 800 an, whae they return to 18 96, then rise to 32 96 at 880 a From 880 to 900 an. dues decline to 24 %. Udy comqmnd to de&cid born thc dmof &her the Victoria GI- or Bow VIUy ice. h Lte Wscorwinrn ice retrea!ed firrther hmthe lake, more otdcrcd

- sedimentation bqm at the 400 an htdwith the deposition of rn inorganic sandy silt hcia. Sieving and sampling for rmclofbds and arbon uulyser began at this interval. An abrupt heies change to gytt~*aa! 510 an likely occurred as r result of the taminrtion of drrtic sahmt idux into WeLouise. Codation of this fircits change to MU ot sbnilu hci~ mt~10- ~unt~lme (thir prp~r), la 0,- ud 1989) ml Cmwfibot Wra (Reasoner a d., 1994) maest that it may have occunad at about 10.000 BP. Daxusd drrtic sediment influx to Lake Louise at this time hmd wtta duity in the Me, d allowed the establishmat of photorynthaic rmcr~phytes,causing insnucd TOC dues ud the abrupt ficies chge to m*a Bcclwe Lake Wse is fd mostly by the Victoria Glacier, tamhaion of

TOC muins hi~tfrought&w8~es,which actads tothe 545 an intend of the core, intu~~ptd 521 ud 528 an by the Mumu tephm (6734 BP). Through condltjons with other mrds, the 510 crn change is intad to luw ocwred at &out 10,000 BP, which dong with the occwcnoe ofthe 6734 BP hhama tephA 521 un, su- that total Holocent dhmt .ccurmlrtioa prior to 6734 BP is only I1 cm, giving M amage dimerrtrtion me for this time paid of only 0.034 mm/yr compared with 7.7 mrJyr in tht pod-Brid&~Riwr htdof con. Although the dy HoIocaw rate is CXttCmdy low, there b no evidm in the core of dumping or other processes which myhve removed dment fkom this intend. It is also important to 5.2.2 CbsalBssin Lakes Copper, Johnson md Summit lJra occur in wious biogwgnphid zones, with only Summit king truly alpine; the rest tie in the montane region, within the Rocky Mountains. M Wtu in this section we coruidcfed dosed bash, which is used in the context of having no panwat outlet, and daiviog JI water input born lpoundwlter, dope runoftot direct 2221 cQwsm!h Copper Wre lies on the floor of the Bow Valley near Eisenhower Junction (Hwys 93 ud 1) (Fig. 2.1), at I450 m rs.l., in BdNatiod Park. Copper Lake occupies a dmeltout deprusioq d has m pamnart inlets or outla. A 4.3 m vibtacore was taka near the cumof the We, in 9 m of wrta. Stable isotope d TC m~~~urcmcnts wac not canductad on this core kauw of itr inadvertent destruction Won samples could be tak.

From 0 to 40 an, Coppa Lake antaha gold-dod, &ve, inorgrnic Mds with isolated pebble-itrd cluu of limestone md quuttite (Fi8. 5.7). Bawc~n40 ud 148 an them is r Mes dune to grey, massive inorpnic dt-cIryy This core intanl con& no dropstones, but doa contain rbundurt chrophyte oogoai. ud chrophyte stem encwdons thmugh the upper 20 an. Molhua dlo mter the record in the uppa 20 cm of this Section of core, with concentrations between 5.5 and 6.6 vdvdlOO cc. Copper Lake

1020301050 10 305070 90 s)n1u100 cc wn Figure 5.7. Lithostratigraphy, macrofossil and TOClTC data from Copper Lake. Radiocarbon aga fmm White adOsbom (1992). SdCti~ofoorcmlaw~wtotb~uahnLwrob13.8nlvdlOOccrt19Ocng ~d3.8nlvrdlOOccat200ud210an.Abovs210aa,mm~nverofoailswac fwndudcbuophytcrmlimitdaltwyto~themulhcia. TOC values fbr Capper Lake m#.5.7) uc low (el0 96) bough the lower 180 a of core. TOC nlues increase to 53 % by 210 an, with the beghing of gynjma sedhentation, dropping to 25 % at 220 an, Mion hxdng to 68 % at 230 cm. TOC dues rrmrin in excess of 60 96 hm230 cm to the top of the con,with peaks of 82 % at 290d 410 cm-

5.2.2.1 -2 Interpretation The inorganic sradr ud rihr in the lower 148 cm of COPLl likdy cornspond to Jtdhncntr deposited by @acidmdtwrters -on of the Bow Vdq. At 148 cm, dmaitdon in Coppa Lake changes abruptly to ddly mul, corrtrinin8 abundant chrophyte mraofossils rad bio@cJlV precipitated carbonate Boa. Radiocubon dates fiom Wte md Osbom (1992) bracket the age ofthis tmmithn betwea~10,490 ud 9740 BP. The mul precipitation in Copper Lakt wu likely cawed by respintion ofchuophytt algae, but may have beat cnhncai by evaporative enrichnmt of dissolved sobin the lake waters. The pmof photosynthetic mvrophytcr ud abundant flltcr-fdig Pisidurn q. molkuc mcrofods indicates tht Wte wrtan were, by this the, he&om suspended dhmts. Although biological productivity began in earnat at this intend, TOC remins low dmthe llyrl BCiO kcYlaa of the rburrdurce of arbonut macerial. TOC dues increue rhuply at 180 in nrponrc to the onaet of diotr, which continues to the top of the core with moUw mrcrofossils leaving the record by the 210 an intanl of the core. The masons for the cessation of mul deposition ud the -on ofmollurun hnain this intend is unclear, although incnrdng eutrophication 5.2.2.2. t Results A 3.4 m core from Jobn hke (JOHNLI) wu ukcn in 4 m of water and is divided into 5 frda (Fig 5.8). Due to the iadvatant destruction of this core prior to s~pwfor My udyses or sievbq for rmccofo~oniy tithostrrtigrophic d8t8 ue prc~cntdhere. The W38an of JOHNLl consist3 of strucnud~inorganic sand. Sedhnts from 38 to 81 an condet of orgudc dysift, of ippt0~48% orpic carbon content. An AMS date on r wood &Ignent fiom 43 an yielded 9440 +/- 230 BP. At 81 cm,thgC h a Mia change to mui, wbicb continues to 124 un, where it is intempted by thc M&mm teph hhm~tcphn in tiis core is dmomuPy thick (I08 an), as ~~~~)thC1~eof10aninot&rawas,dkrcdonviaulhupcaionco~ .kudultchroorlprrrider.At232~hM.nautephn~e3Laoapat~t~(Fg. 5.91, which contains lema of dutic mrtdud dissmhted teph At 280 an, the Pm~udungcrtoim,~criltddry.whichis~~~instru~udcontinues to the top of the awe (340 an).

5.2.2.2.2 lntwpmtation JOWIILake foUows the rune uldimmtrtion putems across the Plustoccne- Holocene bouaduy 8s 8ll of the othef corn in this study. The bd38 cm of the core Johnson Lake

- # Peat Sand Tephra Radiocarbon age i

Figure 5.8. Lithostmtigraphy of Johnson Lake. Peat with tephrai slope wash interbeds

Mazama Tephra

L'6734 BP)

Figurr 5.9. Peat and tepldslope wash ioterkds in the post-Maamma section of JOLINLI, fmm Johlsor Lake. sA2aSummrtLgkQ Summit Lakc lies in the subrlpine zone of Wataton National Pulr, southwestem Alkry at 2000 m id. elevation, 5 km northwest of C~aanLake (Figs. 2.1; 5.10).

Summit Lake

Figure 5.11. Lithostratigrapby and stable hotope masuremenb from Summit Lake. &HoIocaw dmambn in Surrmit Lake is dominated by two distinct lithologies, probably &om two distinct sedhaat sources. The basal IS cm of SUMLl c0ruist.s of a dhmiaon fircia, likely deposited by oordiliemn ice during the late W~scoruinrn. Large pebbles are common in this &on of cote, md appar to be dominu*ly ugikscw siltstones, probably 60m the Belt Supergroup, which outcrops loully. From 15 to 38 an, m inom red rud 6cia Urdy represeaits dqlrcirl deposition of k-gmid qilbow mated. The inorganic red dty sud %es betwem 38 ud 250 an contljrw and luninations and relatively ibund.nt dropstones, suggestbq deposition by scdhncm ldar waters &om a more didgl.cirl position. At 250cm,depodtion~estoinofg~icriltygreyd.y.Thegr8inriccchuyreatthis intend indilrt~lra lower amgy dcpooitiod anironmatt, and the uddcn dirrppumce ofdistinctive red qillite sugeests udhnmc in this fhcies came &om r d8ctc1ltsource, a c~epahrpr~byrltd~put~uglrciJiccntrerted~mtk.rrr The grey clays of this Mes1\30 oxidize vay npidly when exposed to air, suaesting tlpt thy were deposited in an mxic cmimnmmt cucd by pasistent ice cover for most of the yew, rindlu to many uaic Wra (Cdqmd Rust, 1%8). Glacier Pclk tephm occurs at the 297 cm intend, &tin# degkkion u prior to 11,300 BP, and limiting the fhes change to gyttja at 305 an as yam~erthan that date. This is .Iso the hnhest north 5.3 mothlll* L8km Frederick Cutwri@t ud SibbJd Iaka JI tie in the foothills cast of the Canadian Rocky Mountains (kig. 2.1). AN ofthese Ucr w closed basins, having no permanent in or outflow.

5.3.1 FmtWLBb

ktcdetick hke 00ar@~8 Vdw bw wbt0fW f'idg~ the foothills of the Rocky MounElbu 50 km southwest ofCalgary, at 1370 m r.s.l. (Fig. 2.1). It is fcd by ephancnl streams, with both adr of the lake exlibit@ deltas and wethis. A 480 cm core born Frederick We(FREDLl) was talcat from the deepest put of the Ue(4 m).

5.3.1.1 Rew& From 0 to 47 an, FREDLl coroiU of dveinorganic sad, devoid of rmctofodr (Fig 5-12). At 47 an, there is a lrcu change to inorganic silty sand, dso with murive bcddiDg d wntinu* to 150 cm. Between 65 and 140 an, numerous unidcllfifidd bqophyte stems were cccovered, which rppar to haw ken moted into the parent silty slnd materid in growth position. A h$e spcchncn of Gymvls deflectus wu rccovccdd &om the 130 an intend. Bctwtcn 150 md 227 cm, sahnam become o@c srndysilt. Tha~in116rintcnnlwhtk~~ofputicle~mdho~ hcmdchnoJ nvaofouil contan (2.7 ~ts/lOOcc) at 170 an. At 227 arg sedhamtion in the lake changes to dvdy bcdded pat, which contained no organic eolian sMdy silt, with Gmq. mwmmrer0 at 250 (3.8 rbdWl00 cc) ud260cm(l.l rhdlJ100cc). Pammqptmq~~appeuinthe~rda240 cm (7-7 -1 00 a). 2SOcm (1 I. 1 ~100a), and 260 cm (I. 1 seeddl00 a). Muma tepbnoocun~270md298cm,md~ohmbeendilutedbyot&r ~becawe~fitsrbnonnrl~dthe~ofchucorlmdothtr mfdswithin the teph P-m q. rerb conthe to be abundant in this zone of the core, between 1.6 ud 3.8 ~100cc. Charcoal concentntions also incrruc in this intavrl, 8- 2 Iir(pnntd100 cc. At 298 can, otganic sedhentation resumes with the deposition ofr d. Potamrogctm sp. seeds continue thmugh the lower 20 cmofihisunit, withcancamrtMarof 1.1 vtdrllOOcc. ~fbdlrotbodrPi- p. md G-iis were fdin the upper IS an of the mul unit in collccntntions of 6.3 VJvdlOOccud 11.1 rhaWlOOcc, reqedvely. Themui~esauisat373an. changing to peaty -a, which conthues to the top of the core (480 a).This zone contains abundant mraafossil stems of CPror q.,as wdl u incnwing concmtntions of Pisidulll sp. valves (bctmcn .I and 31.6 VjVtS(lW cc) md durcoJ fiygnats (to a

TOC dues wi5.12)~~ lasthrn 5 96 klow 230- where they Jimb to 51 96, dropping hmdatdy above the pat to 4-7 96 ud mdning low unil the onset of partywa~trtionu380~ar5~thytormrrrLnumof55%at450 an. TC~~rrlrtivdyhi~throu~thccorr.Rmrinin~stadyfiwnthe base to 220 an at 12-16 %. TC nka rise rt 230 an in response to incmdorganic contaat in the pat hcim, becornin8 host' cpwl to the TWmemmmm~ from this htanl. TC nluudcdina above this paJc md mnrin Weat 20-25 K from 250 to 370 akloreincreruingto60 K~38Oan,in thepatygyttjr We, raminhgabove43 % to the top of the core (480 an). Organic oqgm isotope dts(Fig. 5.12) show d scale' edc vuiations through the kngth of the core, ranging between 15 and 20 W. through the Organic silt facies

Peat fac lies

rim5.13. Peat smd ovedyimg quir dlt hda bor the core FREDL1, born F~riclhLaTkr~tCf~8ttktopoftk~iru.rtiM oftkem#tiagproadamrrdomtLiram. 70

lower 230 cm ofthe con. A 3hup decline to 4 % at 240 an conapands to the pat hdcr. VJuobaMo260md440aa~arblebetweu1I2md II%, dropping to6 %rt160cmthainC€dngto l4%8t48oan8tthstopofthecore*

Oxy8m isotope mawanam made oa arbaute rmtaiJ from FREDLl (Fig- 5-16) vuy between -6.2 and -10.4 % with several pronounced trends companding to bowdari~.Batwosn 0 ud 40 a nlu~r khr#n -7.4 ud -7.7 %, ins- to -6.2 % at 60 cm with the chan~eto inorganic silty rud. Values art steady between 80 and 180 un, deeming to (1 mhimwn due of-8.5 % betwan 80 ad 140 an. but

MOW-7.8 % d200an, whae thy inrruc to 4.3 W. At 220 ~m,~UCS dccrrrr~to -7.9 %o, mgIOW thmugh the pert Mia. At 260 nlug incrrue to -5.7 %, C,g slighlly higher than the Iowa section of the con until 360 cm and ranging betwan -5.7 and -7 Y. At 380 an, values dcnerr~to -8.8 %, continuing to deckd 460 can, whac they nrch r minimum vrlw of -10.4 %. Values inaew sli@tly to -9.5 WI at the top ofthe core. Cubon irotope meuwumm mdt on carbonate matcrirl (Fig. 5.12) vmy between 0.3 ud 2.8 % &om the buc of the core to 220 an, Md inflection points in 6 13c fiom this section of the core do not wan to correspond with ficia bowduies or trends in other data sets. A sharp inaercc in b U~ dues a 240 an is followed by dccmad values of 1.2 % at 260 an, above which dues incnue consistently to 1.9 W at 360 an. Del "C values incfase rhuply to 7.0 fC u 380, 0,g betwan 6.5 ud 7.1 WI to the topmost in- of the core (480 an), whae they decline to 5.0 %.

5.3.1.z lntemmm nKbrsJino~csrndwuinkRUlLlaaenbto47cm,ud~likdy deposited as r dtof deghd mfF through the linuted topography in which FredJr Lake ties. The bcier chur~eto inorganic silty rrnd at 47 cm is condated to the 10,000 BP climatic shift &om cold Younger Dryu conditions to the wum uid condirtions precipitation. krmmd sbdl rmctofod ud Pwtm(pond wed) sd co~onsktmar 235 ud 270 ens immedirtdy rbove the pat ficies, support the hypothesis of wetter dtionsduring this intend. Above the peat, sedimentation rrtunu to organic Yndy silt. men ud arbon isotope mercunmnts on urbonuc from the p~~ don of the core fluctuate dally, ud may indicate changing pm~ofduticmdpr&i~urbonta.Thc~teplY.ent~thetd~~fd a270an,ndc6ntlbuanrllnwnbanofPdcwrogrtm#dqu~dluincrrrcrd ~ofchvcoJ.'IhrcsdrmdcbPcorlprrraffinthetephnnuyindicatethtit mr deposited by bah initial rirbU ud subsequent dope wuh. At 298 an, Wre sdmumion ion with the ddeporioon of mad in which cubonate 6 "0 ad 13clevels ue higher ud lower, rospsaivdy, than thnc intend of the core, sumestinj~that carbonates in this section of core were precipitated rather than detrital. Mad deposition vegetation for gnrine of mok. hmsing Na@acid wrta idsthrough the peaty ficies lad to imfdng mmks of Pisc'dym p., md the decline of shrllow mter ~rusuch as CIMI qp. ud G-I JP.thtough to thc top ofthe core.

5.3.2 Carhw@htLdcb Cammight Lake (unofficial nun) is a mall, unouncd kettle in pitted outanrh gravel on the Cutwright Rmch, located 30 km southwest of Longview r~g.2.1) md fodin r gkioddtric phwithin the foothills of southwestem Alberta (Rg.5.14). The lakt hu no pamrnan inlets or adktr. and is probably water trblolcdntn,IIed. A 4.1 m vii'bflcore hmCutWright Lake (CWLI) was taka in 3.5 m of wueu rppmximately mid-lake.

Lz?JRssurrs Bctwan 0 ud 5 cm, CWLl cagists of diunicton, ch@g to massive inorganic und between 5 md 39 an (Fig- 5.15). AMS radiocuban dyshof r wwd &qpmt fhm the 1 an intanl yielded a due of 15,670 +I- 960 BP. At 39 an, sedimentation ch8a to Wed mrrl. which cunthues to 92 an, wherr it ullconforrmbly contacts murive pmty gyttja (Fig 5.16). Sieving of the 92 an intend of the con yielded shell haah and abundant wood &Ignanr, which together with trunation of bedding in the marl hcies strongly supports the hypoWs tht this MCSbounduy represents ur erosional unconformity. Bctwan 92 d 102 an, clorc inrpection of the core rev& that disseminated Mazar~teph wu present in the matri~~of the peaty gyttja, thereby

Cartwright Lake

-0 Oiamicton +Radiocarbon Age

Figure 5.15. Lithostmtigntphie log from Carhight Lake Note the uneonformity in the em hrgement. Peaty gyttja facies

facies

Fiill6. EdyHa mcodorJh I. CWL1, fhm -t Llrc Note the mdbdcr kbr udpeatg gyttja 6ldcr above tk mmco.fom@, mdMamm(epLm~itto~tb.6'IJOBP. Sibbrld lake lia in r meitout depression in glrciodcltaic gmd outwash, probably fiom gLdrl Wre -s, at m ddonof 1464 m LS.~., alongside Sibbold Creek Td,60 km west ofcallpry (Fig. 2.1). The Ueis r dodhyih ud is r mocimun of 4 m deep. A 5.6 m vibnam (SIBLI) was taken tiom the aaac of the We in 4 m of Met. frcies. TOC values vlry untidy throughart the core (Re. 5.17). beghhg Wow 1.5 % trom 200 to 230, rising to 11 % a! 250 an in fcsponse to the onset of o@c

vJu~incrrrringdioln2O%rt43001to38%~530cm.Vduesrrmrinlbwe304Lto the top of the core. TC tndt tbolc of TOC throughout the core, indiea uniformlmlofarbocvteinthc~witbthcaccpti011o€~~inaucrint& nwifhcieawhichutattfi'butrbkto~cubolllt~WinthisintCNJ~Post hhama TC nkwr nmrhr rrlrtivsly atdy in comut to inmas@ TOC, indicating darruing arbonate kvdr in the uppa pottion ofthe core.

Oxyeen isotope maswemats muk on organic muter have initial values of 8 %D, climbing stdito a peak due of 21 K at 440 crn in the post-- sdon of thc core (Fig. 5.17). 440 a is &inflection pdn rbon which dues slowly decline to 17 %D at490an. At51O~~irotopenlwrd~rhrplyto9%,udmnrh,ktwcan 9 ud 10 % for the rrmrining 50 un of core. Cubon isotope dues fiom the or@c fhction of SlBLl are exmmdy consistent throughout the core, beghing at -21 k at 200 czn, ud imcming slightly to 20 % at 220 can (Fig. 5.17). At 230 crn, values hcause sbrrpiy to -14 %, declining again to -26 K by 240 an. From 240 a to the top of the core, VJuu vuy between -22 ud -27 %, md show no obvious trends. Danaiwn isotope dysb of adhmts bmm SIBLl mge between 44.3 ud 2227.8 %, sugpstiq once again tiut deutaiwn isotope mtwurcmcnts in 115 study my be inrccunte 5.17). There is diddy synum&d pattern to the values, with badb D memummu of 2215.4 % at 200 can, decrcuing shuply to 444.2 W at 220

cm, ud conthin8 to decline to 44.3 %B at 340 an. From 440 to 510 cm, dues inaerse fiom 158.4 to 484.7 %, but then jump in vJue to 908.8 )C at 530 an. at 2227.8 W.atSSOan n~1cdru~tokr@d~0ndrtionofdv6'bnngbut~sis probably spurious based on the poor quality of 6 D data fiam other cores in this study. firci~it138cmLcutbpothcd~rad~aotlppartokof%lciJori~butd onitsrrlrtionrhipto.djuxntfic#r~iiS.18)~ibr~is~tohvekcn depositdbym~Boodkm~WEC~arhichempI.l.rulunrorted wusepebbb, rrnddriltintheboaamofSibbrldLake. Sibkld Wrtfodinr meitout depdon on the surfhce of r valley fill deposited by gLcirl Lake Kammkis. Whcntbt~Wa~thanlhy-6Uwu~dtheWtc.~autoff~om active smun flow, causing the Wes change to inorganic dysilt at 220 an. The appamce of moUus~mrrofids md r rhup increase in 6 in the upper 5 an of this fhck suggest them myhvc kcn Qght lag between changes in climrtc, sahmt

chncta, Wre chanirty ud macrofods. C&mn isotope vdues at this point WH&C wall to accepted vrlu~for C4 plu*r, whik dues above ad Wow this spike bll in the nn~eof C3 plant mrtairl. It is hypothcJized that the inaacc h arbon isotope vducs indicate dcJining Melevels, which exposed shoreline uas to colonization by CCMJ~sp. and other C4 pluy diluting the omccubon ttsctvou of the lake with hervier cvbon. As algae d other pMdonic.W began to bloom in the Wrt md C3 vegetation began to estrblil on atpod rhorrliw ~u the arbon woirwas brought back to C3 levels. The inorprnic sudy gilt 6ciu mads to 239 TI where it Juneer to gyttja This Wes chmge is data! u old- than 9690 BP bwd on an AMS ndiocubon due &om 245 cm. The change in mollusc too tiom Pi* q+to GJvwIis q+at 239 cm likely Mates krmsiq amounts of quatic plunr, upon which GyrauIis md other grstropods fbl.

Oxygen imtope vJwr which are 8 WI a 220 nn climb to 21 %O a 440 an, immediately above the Ibhzam teph The t#cuiaq 6 'b vJwr uc interpreted to indicate gradual evaporative enrichman of the havy omen isotope in lake waters due to r ncgrtivc precipitation balance beghhgjust prior to 9690 BP d lastin8 until afh6734 BP. The app~nceof chu*orl heen290 md 320 an suggests m incnua in forest fire fhqucllcy, supporting the hypothesis of wmner, more wid conditions. The beginning of a mul hciu at 338 an may be indidve of high Idsof evaporation in the lake lading 82 to incmd collccnSnfions of dirrnlved mli& md more nrdy precipitation of CaCQ. Gy~ovhqb mrcmfbh which pak in macentdon in tbc mul hda may be indicative of brnrrod~phtrnilrbiliryin~toWrcInnlto~.'Thedfkh endrinthekLlMImrt37501. ~~~inSIBLlirdytbidr whichmy~~deporitiondurirythisthnc,~by~derardrtion duetodmu@radlah. The~~rbonthe~tepbncontrinrhrge numkn of GYIQY& qp. tnacrofbdh though the lower 30 an, fhm 425 to 455 cm hmdng nutnbcm of PIjimium above 455 an correspond to the iddon point in 6 "0 at wbich VJum start to decline, indicating r return to podivc precipitation bd-, and suggesting rising lake lev& inwead available Pisidlium sg. habitat. S 'b dues continuetodcclint, ruching9LatSlOan. Vrluum~inbetween9md 10%0thtough the~50ariofcorrThebuJ618~vrlwof8%, C,thetopmonvJuesof9 and 10 % comepond to nlum of meteoric water and suggest that thc lake was in equilibrium with atmospheric ptsdpitation in the pre-Holocene and Nco~aciaYmodern portions of the core. TkWopbuindpbra-LWdudy~dMnodlybyWglrciJ mdtwrta, bmm modan glaciers. Uppa tbuwkir d lower Bumtali Wres lie on opposite sidesofa binage divide, with 1oaraBunull ttd by the Robeman ~~t,~UppaKuvnJrisfbdbytwosLdqtbckgrrtofwbichirthc~g~~ which ties opposite of the Robatron. Me Louise ties dirraly dowmnlley horn the Victoria Glacier, ud is fkl mostly by glriJ mdtwlter. M three Ues lie in confinsd, d dninyle buinr, rod colwc~uantlydaive mch of thdr chic sediment from these rwces (Rg. 2.2.2.3.2.4). Cores fiom thecc three Irku ue strikhg in their rtniluity, with a& containing an abrupt, confonarbk fida change tiom clutic to organic sediion. In all three lakes, this frees chqeis proposed to have accumd irochro~~)~sly,at about 10,000 BP, on the buis of AMS ndiocubon dates hmlower Buntrll Wte (9180 +I- 60 BP) and comluion to radiocarbon dates of 10,070 ud 10,020 BP fiom Crowfoot Wre (Rcuoncr et d., 1994) ud 10,100 BP fiom Wre 0'- (Reasoner ad Hickman, 1989) which bracket the fhcies change mg. 6.1). Sedimentation prior to 10,000 BP in Upper Kuunrskis md lower Buntrll Muud Wu Louise consists of glaciogenic sad, silt and clay. The uppermost portion of these Mes were likely deposited duhg the Younger hyu @aciddnnoe (Rasom at J., 1994).

WSmd Hod(1977) U- 8 dvulct of thc VK~OMGl8Ck fl clbout 8800BP,~on~ruationthtthtLJcetouiccwudunncduound8800BPby a glad monine (upon which the Chateau Wte Louise hotel is constructed). The age detamhation was made for the Chtau Lake Larise moraine by correlating it with data that sum Uppet WItafowl Lake was dunmcd by the Noyts Creek fan at about 8800 BP (Huris ud Howell, 1977; Smith, 1975). The core trhn from Wre Louise in this study indicates that r date of8800 BP for the fodonof the lake is fir too young The lower Burstall take UPW Kananaskis Lake Dimicton Tephra --- - Lake Louise

Figure 6.1. Comparbon of litbostratigrapbiea from Cmwfwt Lake (Reasoner d QL, 1994), Lake OtHan(Reasoner and Hickman, 19B) and corn hmtbL study. Note that the 10,000 BP isocbran in Upper Kananasku Lab and Lake Louise is not dated, but is instead corre!ated on the basis of facks cbangcs fmm claatic to organic sediment. t c-c &om to o@c saheaWi01s dated to about 10,000 BP in otha lakes, is prrrnin1&b~wn,radtbrrum~~~ofagLcia ov~tba~rftatbirtimnWowthe 10,00OBPho&oa,therebroncmetre ridckLautrin3iltprdcleeuda&nba~o€ica~~01~mrtaiJ which prsbte 10,000 BP, arma&ingtht ice was in a didposition to the Uelong before thia time. Abovethe 10,000BPw~~on~tomulinlow~Bunullud Uppts Kuunulds Ua. Bad on the pmeace of dumphyte oo~oniain lowcr Bumdl Wrqwrldaporitio11rppavrtob.ve~~dby~eb~ofdgu,wtdch remove excess dissolved C4&om the water column, uusing an equilibrium reaction in lake watm to shift towards the ptoducts side and precipitate CaCa. Dramatidy incrsucd TOC values in this intdsuggest that dochthorous productivity in both lakes began at this time. Mul precipitation myJso have been aided by evaporative enrichment of Uewaters in dissoM rdib aurad by climatic warming. Sedimentation in Upper Kamdcis ud lower BdWrcr wmprscr wdl to that of Crowfoot Lake (Rcw,ner d, 1). Condrtions between the three corn in this study and Cmdwt Weue presented in Figure 6.1. Scdimartrtion in Lake Louise dro chrnses at apptoxhaately l0,OOO BP, but wa is dcporitcd ntha than 4. The reason for the differc~~cein sedimentation is not brown, but may have been caused by Wer dissolved solids in Lake Louise. The mrrl6ciu in both Upper Kamdcis ud Iowa Bunull Wtu is rban 10 cm,.bow which there is r bcics change to gyttj~Incread organic carbon content in all th~a~~s~ir~CIti~tofkogwdaupandtdsrdimartl&hchamta wlqdowing more ii@t to be mmmitted, incrwsing photosynthesis ud thedore productivity. Abu&nt PZrid~vnrw. macrofossils in the mul Mesin lower Burstall We dm dect dccmacd sucpaded sahcnt lodr, as members of this genus are both filter f-g ud gill brathing .nd wiU mt live in CllVirOnmen~with high swpended sediment loads. The low mounts of suspended clutic sediment in the arfy Holocene portions of these cores su8gest that the alpine glaciers farding each lake hd completely mdted, whik the sharp nature of the bder change fiom dutic to organic setlimntation u 10,000 BP with rrmorphaic Ca. Prior to 10,000 BP, cubate lbdJ mdhwm cnmhg the Ue system dissolved, ud Ulmugh isotope cxchmge maions eqdiibnted dissolved C& with the 6 'b dues of the rumwding btdlOEk When glrciJ sediment supplies were cut oft. Co2 diddin Uewaters was no longer in coma with bedrock carbonates, and became equilibrated with atmospheric C&. OxyBa isotope merrswemerrts made on clutic carbonates fhm LBSLZ cormpond to pre-10,000 BP vrluu in organic oxygen isotope wtrile post 10,000 BP on o@c matter eomrpond to rtmoqhnic C@ dues IS 6.2). Cubon isotope wuunman~ron organic ud cubonate merial hrnlower Buntrll Lake dmthe same trends, with pre-10,000 BP organic 8 U~ dues in equilibrium with arbowe sources and post-10,000 BP dues cocqmnding to atmoqhaic 6 U~ (Fig. 6.3). Fluctwtiom in C and 0 isotope values in the port-bhama section of LBSU ur utriited to mewed activity in the Neo~rlud nryine proportions of mn~sphaicud balm& inputs. wid OlrdJ mcdon at the beghing of the Hotocuw indicates thrt climate warmed -ply at this time, with inemad tanpmture ud deamd precipitation lcldingtorncgrti~fmur~htheglriarf~glcdimemtothcsel&~.The &hemtology hm-crowfoot Lake (Raroner et d., 1994), ud Lake OBHm(Reasoner d Hi- 1989) ir my dn6Lt to the thee corm in this mdy, qgesting that the Crowfoot, Oprbin and Otrr glaciers hddm mdted by this time. A sericr of rdiocubon data on wood taken &om the hnt of the Athrbasca Glacier indicate that not only hd the &cier rematad wdl byand its present terminus, '" (SMOW)

Figure 6.2. Comparison of bedrock and atmospheric "0valua with changes in organic "0in lower BuntaU Lake. - - -- I 4 -9 -14 -19 -24 -29 -34 '3C (PDB) Figure &3. Comparbon of bedrock and atiospheric6"C values with changes in organic 8*C in lower BurstaU Lake. Black ban indicate variation between atmospheric and bedrock6 UC,aad the degree of change in organic 6 U~, C.vc,neu~eguud~~theCalumbLIceF~indicrtartbrtthehrendof theave, whkhcadruadertheiafidd, [email protected]. Fod,prs canm, 1996), uggdng that the Wmbh I= Fdd bd lowed in Umee dention by atkrrt25U)m. Tbaedruuppat~tiornlraurriDcrrcocdrwhichsuglprt dveglrd.l~iathcarlyH;obcsnt. Organic lsdimcnttion in them oontirrues until jurt .fta the 6734 BP

6.1.2 Clbsed8asin Lakes Sadhemion in the kul scdms ofcopper, Jobnwd Summit Wm consists ofinorgrnic sediments which were likay deposited during recession oflut Wwconsinur mountain ice, unda pm&chl coaditionr. All MUu appear to have been heof gJdice prior to 10,000 BP, ud contain 10w-ata-g~inowc Lcwtrine silts rad clays immedirtdy prior to the 10,000 BP isochron, u which the, rll dvct Uesundqo an abrupt fkia change to organic sedii. Summit Lake, which is the southctnm~stlake in this study, contains Gluier Peak tephm immediately Mow the infend 10,000 BP contact, indicating that the cbge in -on occun &er 11,300 BP. An AMS mdiocubon date born imtnubdy above the contact in Johnson Lake limits the change in -on to dder than 9440 +I- 230 BP, while AMS dates by White md Oaborn (1992) Wet the change in Copper Wte to between 10,490 ud 9740 BP. Though their record did not atmd through the HoIdccnt, Luclanur and Ksur#y (1986) rhow tht organic -on in a bog in the Watchtower Bash, Mgnc Range, Jasper National Park hh commamd by 9500 BP, ud thu by 8770 BP, timkrliner were u least 100 m hiehadun present. Or@c productivity in Coppa Lakt begins at about 10,000 BP Jta m abrupt fkies chnge &om inorganic tilt-clry dimants. Chuophyte oogonia d Pisidim q. mocrofo~sindicate that We men were mostly ficc from suspended ditand conditions, md fadita!ed the fodonof part. Assuming that pert forms only in Wow w~a,thtdi~~~~~WreuaCadtbebrccofthcpat~~in JOHNtl indicates the appxhtemount of We Idhcmm since deposition of the peat. In JohnLake, this crlcukkm sum that Uekvds immedirtdy der 6734 BP were as much u 5 m lower than rt preaent, resulting from severe drought conditions at that time. Chute change in the f& of muhmtan Alknr ir mfkdin the LLc rscordmnsdrt&umcw8yuinrlpiwuaa* ~8nd~~~e upthcburlportioaof~foo~~wbidrco~8~Hd~~d.At rppro~10,000 BP, in rrrpoau to &nap clinrtic wm@ orpic ptoductivity atutdmlrhriatbbthills,withhciu~topIyltj.inSjWJdmdCuhnipbt Wres,mdto~rudmF~Lake-Onthe~ofanAMSdOCUbOndrtc fromSibb8ldWrt,thuechgtsocansdpiorto969OBP,rduswhkbrlp#swith drterfiromothahLaiathissardy,~thacdnmrticch8nge8indhnrteocaaral at about 10,000 BP. The Wes changes in foothills Wres in this study, and dates amdated with them ue supported by llwmtous other studies on lakes and bogs in the fe.Bra&* docubon of 10,400 ud 9395 BP on wood fbm Wedge Me, Kuwrulcis Country, Alkry date a amrition across which mollusc mrerofosdls inaeue in &dance by more tha 40 shdls/S cc to appm~dyl0,OOO BP (M.cDodd, 1982). MaDodd (1989). in a dimat core hmTobo~grn Lake (unofficial name), nar Bnge CeAkCa, obuincd 8 bte of 10,400 BP immedirtdy

Wow bdes chnge born inorganic lake sediment and diunict to ~CIVCOUSorganic dhcnt. In both paps, MaeDonrld su~estsdut the climue during the dyHolocene wu thn in modem times, nd that cool@ began somaims .fta the 6734 BP Muma tephm. On the krir of r raiar of ndiebtu on the 4Ultic moss ~e~~ cmsicas&tw, ChJmar Bog ir rugscrtad by Mott ud Jdn(1982) to hve ached for ova 18,000 BP, at one time ocarpyin~the ice hrc comdor. Subsequent reseaah has illustrated that old cubon anr in aquatic pLnu &om areas with carbonate badrock myaue dates to be up to 6000 yam too old (M.cDodd r J., 1987). Given the Guncwork of dates d hda pmgmssions ftom othu lakes pmented in this study, it raanr u though r hest Plastocarc/dy Holocene for the oldest portion of this record would be mom appropriate. Polk data fiorn Chlmas Bog are within the fhmework of wht would be expected under the pmgkid conditions of the ice-fk comdor watt ud Jackson, 1982). Upon re-impdon of the dUr, the abrupt increase in pollen influx rates and the deposition of shdly marl appears to comlatc with the 10,000 the 10,000 BP isochron, while pollen assemblages viewed as arctic tundra should probably be reinterpreted as grassland communities which would likely have dominated a drought-stricken southern Alberta A late phase of Glacial Lake Calgary was proposed to have deposited shelly, organic sediments into an ice-dammed Bow Valley at about 9650 BP (Harris and Ciccone, 1983). A rebuttal of this argument suggests that these lake sediments were in fm deposited in a small lake on the former floor of Lake Calgary, sometime after it had drained (Jackson, 1986). The mollusc, carbollate and charophyte macrofossil data match almost exactly that of Frederick Lake (Fig 6.4), which lies less than 20 Ian fiom the site in question, and Hanis and Ciccone's (1983) date of 9650 BP occurs in a stratigraphic context which is very similar to dates fiom Sibbald and Johnson Lakes. Based on the similarity of data between this lake and others in this study, it is suggested that Jackson's interpretation of the cucumstances of this paI-lake are correct, and that Harris and Ciccone (1983) document a transition from Younger Dryas conditions, ending at 10.000 BP, to increased aridity and warmth in the early Holocene. Clastic sediments immediately above the 9650 BP date which Hanis aad Ciccone (1983) suggest were deposited by phases of iceberg grouding are interpreted to be eolian materials which were transported into the lake basin during low water st-. These materials are interpreted to be eolian rather than ice rafted on the basis of the adjacent organic fkcies, which are not consistent with the hypothesis of proximal glacial activity, as well as regional climate data from other lakes in this study which suggest that climate immediately a&r 9500 BP was in fact warm and arid A similar clastic facie which is approximately the same age was identified in Frederick Lake* and determined to be eolian on the basis of mactorofossil assemblages contained therein. The resurgence of aquatic molluscs and ostracodes abow the 'iceberg debris' facies may correlate to the period of fkshening identified in Frederick Lake. Assuming that Manma tephra was not present in this record, it seems as though the lake basin had entirely infilled prior to 6734 BP. Comparisons of the -graphy between Toboggan Lake (MacDonalld, 1989)' the section detailed in Harris and Ciccane (1983), and other foothitls lakes &om this study are presented in Fig 6.4. Toboggan Lake / Lake I Frederick Lake 10,000 BPI Lake Calgary lsochron Section Lake Figure 6.4. Comparison of lithostratigrapby of Toboggan Lake (MacDonald, 1989), the Lake Calgary section (Harris and Ciccone, 1983) and the foothills lakes from this study. Note that the 10,000 BP isochron in Frederick and Cartwright bkes b not AMS dated, but instead correlations are made on the basis of facics sequences. S~oninFddckWrcvuappm@y~by~wuhud~~tiur proccrwrthtoughthedofthe~tothedyHdacmqmdthadricr~ u l0,WO BP is not u obvious as in otha b.In Si'bbJd We, rsdbnenution after l0,OOO BP consis&s of -8 with vuybg COjlCCllftlfi01~of molluscs. Sueoxy~ isotope adysb of or@c dhmta &om SWWre Mate tht climate during the arlyHd~ccnt~~wunaudmoreuidtbraapmt,udthar~vewua b.l.nca existed in SIWLake @om l0,OOO BP unail bmdhdy dkthe 6734 BP hrlrnmrtepln Thesunc~vewrtabrlrncecvlsedC~ghtLdcetodryout entinly, cutting m unconfbnnity into the mad. Cutwriw Medad immediately prior to 6734 BP on the buis of dbnbted Mam~teph in the peaty gyttja immediaely above the unconfonaiy. Frederick Wte was likely dry or only ephemeraUy wet du~g the pre-mperiod, with the exception of r thin peat Ges, which is bounded on the upper side by organic eolian sandy silt which is immedirtdy Mow the Mamm teph Butd on the numbem ofPol~ttcnq. (pond weed) seeds md the rppamce of aquatic mUwc rmctofocpilr, this environment is interpreted as a Wow water environment. The ficdwnine ofFrederick Wa in the pmMizunr record may correIate to the resurgence of 4dcrmcrofodr in Huris ud Ciocone's (1983) WIe Cll~uy don. The retum to eolian -on in Ffcdack Wee immedirtdy prior to the ~t~phn~yindiatctht~ralcMbdccliardrft~8bricfhighMnddh8pgt deposition, but in light of the continued praence of qwtic rmcr~fod~through this f&es it seem more likdy that this chaqp indimes re-advation of mliur ptocessts in the area. The post-Aham section of SWMe consists entirely of gyt?ja with .bundmt shdl mrcrofods. Changing populatio1~of pulmonate md gill brathing moUua a! the top of SIBLl suggest wtltinued hsknhs ud &ling of lake waters into the Neogkd md Little Ice Age. Sadimcntrtion above the unconfonnity in c.mmi@ht Wrc is ddyshelly &a, with rkrndrnt a~lplaof lqu phonate ~OUUSCSsuch as Fossmta q, SkqpiCrOIb JP. d 0thAlthough the ddly gyttjr Gcies continues for 3.2 m to the top of the core, the deporitionJ environment does not seem to change, i.e. deposition of which dm~esin cubonate oxyeca ud arbon iwtope values indicate accurrsd by wpitrti~nntha thn ~OCWOIWUS-onn Thc ruto~hthol~~~s precipitation of CaCa in the nurl frees indicates that that must bm been water present in the basin at this time, dthargh pahrps only ephanarlly- Above the mul, sedimentation chnges to pcuy gyttja which continua to the top of the core, indicating r return to wetter conditions in the Neogkirl. Cubonate oxygen nd carbon stable isotope values rise ud decline, rrspccDivJy, rt this thn+ to nhKs comlrtive with bedtoclq ugsestiag the ad of autochhomw precipitation, ud tM arbonate idux in this fhies was through detritJ processes.

fhe main focus ofthis study is to rrconrtruct past climate changes in southwestern Alknr; however, the hdhgs conelated ktw#n Wrtr in the study maalso cornlate to work outside the study in southerwtetn md northan Alkrtr, the Gn+nlud ice corn ud northem Europe. Brrcd on the strength of them condrtions, the .uly Holocene wmpdod md the 10,000 BP-isochron will k ddresd in the tiunewodc of r hemisphwide mmt bqhing with the tcrminrtion ofthe Younger Dryu wid paid at about 10,000 BP (Fie- 6.9. A bad date hm Huris Lake, in the Cypm Hills of southerstem AlkitJsdclthwestern Sukrtchew~indicates that organic sedimentation in this lakt commenced prior to 9120 BP (Smchyn, 1990). Although this study docs nat contain evidence for the hpttmdion to organic sedimentation at 10,000 BP, climrtt Crowfoot - wA Crowfoot 7- O'Hara i- Burstall + C Johnson f C Copper 7 Copper C Watchtower i

-I Sibbald t- I Toboggan f Wdge C Wdge k Lake Calgary ' Kearl i * Hams Madjarn(Swe) + t Madjam(Swe) ;

I Torteberga(Swe) - 1 10.8 10.4 103 9.6 9.2 Radiocarbon ka BP Figure 6.5. Data from lakes in mountain and foothills areas of Alberta, as well as from three lakes in Sweden arranged by sedimentology and age. Blue points indicate that the material dated was taken from aa inorganic matrix, pink from organic Stud* using bulk data were excluded (see discussion for rdereoca). betw~~19120ud4500BPisinfinsdtobc~~tudwumathurmod~111time)u.cAon pdlm~wbichtdi~bw~of~~on,radrrlrtiwly ~rtrub.odhgb~o~(~1990). Ahnldrtcof7325 BPhm Chappice Wre. in southstan Abar, b again yamea tbrt the 10,000 BP isochmn (VUIC~,1992). On the buir ofrhaeline fhrcturtions ud nvcrafosdlr of srit-toknnt ud intolarntsptci~clhMe~~Wmd4400BPirindarrdtohvrkcnwuma~ dfiu thn at prrrcnt, with Sasonrl Water-kvel flucturtiom md hi& rrlinity prior to 6000 BP. At6000BP~thchirtipp.rraly~paennirUym~,bW~rrlinauntil 4400 BPSwhen hdophyte hdhW of Wlt antas (V- 1992). Vure (1986b) presents data fiom EqgfCIlCSt Lake, mrthwest of Fort McMunry, in the Birch Mountains, which su~geststhat organic sedimentation commenced in this area by 10,740 BP. A gastropod zone hmdhtdy prior to the gyttja Mesprobably famlates to the 10,000 BP isochron diddsewhere in this study (Vane, 1986b). but qpurs to k too old to be considered put ofthe rune event. The 8gc di- between the Eaglenest Lake ncord and otha dated chronologies myrtan hmthe het that there are bituminous deposits in the vicinity of the lake which myhave contributed old cubon to the bulk sediment samples submittal for dating. Derpitt attempts to ranove the bitumen with dous organic solvents (Vmce, 1986b), it is possible that isotope achngc ractions between bianen and other organic moIccules may hve contributed enough ded cub011to the sunptes to rada the dates intecunte. On the bosir of this potential aror,itisprobrblythrcucthao@cWon~in~errejtWre~ 10.000 BP as is indicated in other studies. Karl WEq approximately 55 km mrth of Fort McMumy, was coral by the wthor (kicrle, 1996) ad fdto have r record exta&g back to degkhtion. AMS docubon analysis of r churrd needle fiygnan from immediately Mow r fida dwse hminorganic We sediment3 to gyttja yidded date of 10,lOO BP (Fig. 6.5). sugsesting that the npand drte at Eaglenest Lake may in fi* be erroneous. Although organic productivity in Karl Lake muins high throughout the

Holocaw, 8 shelly mad Micr &d to 5430 BP suggests that lake levels myhaw fluctuated during the mid& HOIOOCIY.Studies on Gddeye ud Moore lakes, louted in ccntnl Albcontain dirtom dlageswhich m used to distinguish between saline ud fieah WItCR @&knm and -, 1993). Tbc bulk rulimn chto~fjOmOdrhycWreis,bytheuthm'~suspectdwtothep~ ofdinth6~md~onrlorrbonrte~udtiu~~udS~~u, 1993). On the bash of 600 yew arar oa ndioarboa dates ofBridge River (2350 BP), St. Hdau Y (3600 BP), ud Mham (6734 BP) tephs, dry enhate that old cubon anwurbart600~dthrt~tlilalyt&old~a~~CddimSodof~ dater. AlPpc~h~diulmtrrqdthc~adinctionof~cr spcci~oocunduringt&ine~ItbeydrttubetweeaM,SW ud 11,400BP (Hicbnur md Schwqer, 1993). Cornpad to strati- ud PJcoclhnue rrcorwtluctions fram 10 lakes in this study, u well u mother 7 tiom other sources, it seems a more reasonable choice to attribute dine diatom species inatucr to the dyHOIOCCIIC, Rtha thn the Youngm Dryu ud older. Rdiocubon ages fhm Moore Wre (Hiclanur d Scma, 1993). Jthough rlro using bulk rcdhnar samples, scan less dccted by old arbon. Once again on the buic of rrlin ud hhaterdirtom counts, Hickmur ud Schweeg (1993) note m htdof dodrma by vlinc trg dthaugh the docubon ctvondogy in Moore Wre suggest that this intavJ oaamd ktwan 10,200 ud 5850 BP, with some dtlucnutions until 4470 BP. A dim phrt in Moore Weheen 10,200 ud 5850 BP cornsponds wdl with other rrudia in the Alknr, which dso suggest low water studs during the arty H~OCCIIC,ud m inception due of 10,200 BP is wdl within error of the 10,000 BP bochron. Hutton et ol. (1994) suggest dut chute in the Muin Wresre&no€cmtd~southofFonMcMumy, wu morerrid~9000 ud5000BP,bwdon~di~udl~m1p~of~sp. spores. Inacr#d TOC daiwith the 10,000 BP irochran in other Alberta lakes appem to occur in Uuirnr .meat about the sune the (Hutton a J., 1994), ud Jthoueh bulk doarbon dating wu employed rt hhh~We, the chronology presented is consistent with ot&r Wra in this study. The excellent codation between tk riter studied in this pqm ud those of otha wohsuggests that abrupt climrtc change rt l0,OOO BP is r ubiquitous phenomenon in Alkrtl, ud that inaued productivity in tams of TOC, mrcn,fossils, dihoms ud polkn at the 10,000 BP irochron mybe reiiably used to comlue lrarsbine records throughout Albatr Oyson~pemsuurrmcm~ftanthcDYE-3OrcaJladioccoreindiate clLrvtiedynec~rt.bous10,WOBP,inwbid,~inarvdbyu much u fC in 50 yam ~~et J., 1989). Alley et d (1993) &tha dncd theae c3timrta in the GISP-2 core, sugecnine that the lcturl paiod of dimate ch~ewu as liak u 3 years, d h bted at about 11,640 dcndlv yam BP (-10,000 radiocubon yan BP). Both ice casr point to md rbnrpt ctimuic wmhg at 10,000 docubonyaurBP. ~timingir&rrhgminondinEuropcrnWcersco~whichue inmany uses mom reiined than thoainNofth Amaiq mdconuiar identical putem of climate change acrm the l0,OOO BP bamduy. Eumpan teminoIogy ditfers fhm North American, ud what has kar previously diedto as the early HOI~warm paid is dmed to in Empan studies as the Prrboreal. A Klies of 50 AMS ndiocubon dates from three Swedish Ues, indicate that haeases in TOC similar to tho& obrcmd in Abau occunrd between 10,145 and 9875 BP in Wrc Tom l0,OBS ud 9900 in Wre Mjrllq@n wd 10,060 ad 9990 in Lake AWtjun (Fig 6.5) (Bjorck ct d., 1996). Bjorck et cJ. (1996) Jlo note tht the flicies change at this time uswllyocounoverktwear 1 ud5~oonl~~m~~g~tbc~echagcin Eumpe wu as rapid as in Alberta. Stable isotope dues, rmcl~fossilsmd pollen counts also change abruptly at &out 10,000 BP (BjonL et d., 19%). abmwtions which dso much mrds &om Mbatr. Thnwgh condatt'on of Swedish and Ciarmn tree ~g chrondogia, lrurtriac mcords barn POWdeep oorrn uwcr &om the North Sea md ice corm bm BjOlFJE et d! (1996) sum that npid warmin# occumd at l0,OOO BP throughout mdmn Ewope. Comlrtion of muitiple independent dcndticrUy dated records such u ice coreq tree rinm ud vwe chromlogier is important in dngthe u~uncyof radiocubon mtwumnents which, becue the ndiocubdn plateau at 10,000 di~nyanBPisrlmost600crlendu~wide~dd~~tby600yeu~butstill hvc the sunc ndiocuboll age (Stuiw a J., 1993). Lake records conel.ted to the Swedish vwe dwndogy indicate that dhwc chmgd tiom the ddof the Younger DrYu to wuma Prrbod conditiotu at hut 10,800 Swedish Tihe Sale Yevr BP (STSYrBP), or .bout 10,000 docubon yam BP, resulting in bdes changer &om inorganic clay to organic gynja with abundant shell macrofods, much the same as in 100 Alh(S. Bj- prrs cam.. 1995;(- 1995). Rdioarbon dwr fhm tbe Gazuwe, Swittalvd dm phce the cad oftk Y-u Dryu at 10.000 BP (Rundpag 1995). In the hose Fkdn Dmdr, TOC values rise by 35 % at the YverDryas- Prc-Boreal bounduy indhhg immd poduceivity, while pdkn ~~eschange to rektwumr dinrtc dwhg the ariy Holocme (Sehwrlb a J., 1995). Investigation of rn Iodrndic Wte (nrmt not m)by lludprrn (1995). indiatu that productivity in thatWrc~~rt99(30BP,Jaqltwith~pdknrccumrbtion~1~ and d&rl microfbssi&. Funhcr inmaam in orpvlic carbon content md algae cows u 9400BPsu~thtclimrtehdwunod~morrby~timc,lcdiqetoincrrwd periods of open water ad the establirhmcnt of ddshrub species in the area around the lake (Mom ud WSin. 1977): In Lake Neuchatel, Switzerland, organic arbon content inaerccr and chrneing &om I.rmrh&ges muk the truuition fiom Younger Dryu to warmer Pre-Bod conditiory again at rbaa 10,000 BP (Reasoner md Hickman, 1989; Reasoner et J., 1994), ud oysca isotope on mad from Wte Ting#de Trask, in Gotland, Sden indicate that 6 'b dues decline by almost 4 %W between 10,100 md 9910 BP (Wbitc ud Osbom, 1992) in response to &apt CWCwuming. The &apt change in climue at about 10,000 BP which is murified in rll 10 lakes in this study as well u in the work of others appe~to be synchronous throughout Alberta md the Northan Hemiqbue. khmtaion in all Urn in Usstudy as well as those in others dynllcr fbm &tic to organic rppmcbtdy 10,000 BP (Fig. 5.6). fhec~esindimrteaurcdinaeucduiditydwumbbawan10,OOOBPmd about 6734 BP, read- in the complete rbtrtion of alpine glrdas and lowering of the water ubk by up to 6 m in dowd kria~arin Ahem Studies fiom sites dsewhefe in the northan hanisphen &ow the ume tnnsjtion at 10,000 BP ud sugeest that this phenomenon is global in de,md that the ariy Holocene warm paid had significant envitonmntd &kts worldwide. CommoNhiesmrcdimmtrtioamdhdcr~~Wrainthis3hdy and OMindicatetbrtr wid, high Mgaicudc-e indiwta at the end ofthe Y~~cddpaiod~dmvtic~~inWurintherwtbanCuvdirn Rocky Mantriar and Cwtbills. Aimapt Gfinvtic warming ud dammed precipitation d8lW@W~kluraia~jJbCbd~wlldricadiddr,Whkh compktaydtedmdutabli~~~on~in~downstremof thun. Ssdimaddogy ia Uppa Kumukh md lower Buotrll lakes, ud Lake Louise indicate that glacial recession was vuy rapid, with the change &om clastic to o@c sedimentation ocauring-inkss than 1 an of core. Stable oxygen and arbon isotope

valuer of O@C mhent &om lowe Butall ud Upper KuvnuLis lakes change dnstiuUyrthir~mbouobry,mo~hm~ibriumwithkdmcLCdOsources to rtrm,sphaic C& indicating the tamindon of intcncb'ons between kbock dgived UrbOnrtcsahentsmdUewrten. BscurethescWreslieinooofined~c~ ud are fd almost entirdy by meltwater ud precipitation, dunges of this nature indicate that *em fdgUpper Kuvnulcis ud lower Buntlll Wres hd completely melted. Complete ghhI ablation is supported by the onset of organic productivity, which requires cl-, dhmt-he wrtcr to tnnanit enough Mllight to pen& phot~synthesi~. Pidcdium q- mamfdin lower Bunrrll Me dm bdiatc rku water, u this gaw of mollusc is both filter ud gill bmthing and will not live in envitotments where there b aupaded rcdima* in the water column. An AMS ndiocubon date of 9180 +/- 60 BP from organic sediments in lower Bunt.U Lake Mates that this change in sedimentation hd occumd prior to that time, while r series of AMS dates bmLake O'hud Cdmt Wre indicate tht the taminuion of glacial sed'untnt influx occumd at about 10,100 BP (Rcuollctud H&m, 1989; ~nuutd.,1994) Closed basin Wres in the Footbills ud Ro& Mountains Jso contain an abrupt fhcs chur~efkom clutic to organic sediment. Copper, Sibbdd md Summit lakes JI switch born inor@c sediment to o@c gyttjr ud/ot mad over the space of less than r centbe. This truwition is bracketed between 11,300 BP by Glacier PC& tephn, which 102 acc~nimmedirtdy Wow the hdar coa~stin Suamdt Me, and %W BP in SlWd Lake by m AMS ndiocubon hmdbdy above tbe coarrct. Rdioarbon dam fmm Copper Wre Metthe corrtrct betwem 10,490 md 9740 BP (White md 1993). Comhionr to data of 10,400 BP 6mn Wdge Pond @bDodd, 1982) ud Toboggan Lakt @hDom@IMO), md %SO BP ban an uMund f- We nar Cocbnne (Hamis d Cine, 1983), dl in the &odd&,atppoct a date of rpproximudy 10,000 BP for the aawt of orpic adbmmi011. In Sibbeld md Summit Wnr. sdmmtion runah unchanged throughout the Holocent, but stable oxygen isotope ~tsono~cnrnahmSibkld~ehwrsrrahvdueuntiljwtrftatbe 6734 BP Maarm tephm, when they begin to deckwith the onset of the Ncoglacial. 6 "0 vJwr in tha p~H01~dNd~gMd hrtds of Sibbrld Wre -8 ad -9 U., rsspcctivdy, rugsartine blre watan were in apdiium with mnosphgic precipitation at thue times, while heavier nlua tbmugh much of the Holocene indicate evaporative enrichment of the We in 'b due to r ne@w water hlmcs. Declining 6 'b vduu just rtta 6734 BP indicate hawing pcdpitation until mnawlly lake waters equilibrate with atmospheric precipitation. A Ad-rich mul kies immediately above the l0,OOO BP contact in Copper Wesuggests possible evaporative enrichment of lake waters in dissolved solids, 1- to precipitation ofCaC0, in response to mwrophyte respintion. Frederick. Johnson md Mghtlakes were Wow during the arty Holoccnt that a ne@ve wrta brlvloe W to the complete dessication of these lakes, ud the emplwmcnt of Wow-water peat WCSud wlconformities. An AMS docubon due of 9440 +/- 230 BP immediately rboM the onset of organic sedimentation in Johnson Lake data the tnnsitjon as prior to tiis time, in agmment with the 109000BP date su~utedhr dndlrt changes in other Wrer in this study. Frederick Lake appears to have been infW by eolian wd ud silt &posit& into M ephanml pond, with r paid of ~~btfore6734BPw&napatheierwrrdepoSited.Sealsborn Potomogctmq- @nd weed) Mate r Wowwrta enviro~nmtpersisted in Fdaick Lake until Jter 6734 BP. The period of fdmhg in the pft-lblazam section of Frederick Lake myCocrclrte to r shell-rich orpic dry Ma described by Huris md Ciccone (1983) ud a period of dcacued tanperature at about 8000 BP noted in the The co~onof dater ad conditions between the 10 lakes detriled in this study An isahnour Meschnge bion elastic to organic sedimentation at about 10,OOO BP lppurs to k ubiquitocw thtou#mt Alkrtr, rod possibly the Northern Hunisphcre, UKI is ru~estedu r mgnphic muLa bed for use in Gsun lakt studies. rUky,RB.,Meue,D.A, S~C.A,Gow.AJ.,T~,G.C.,Omotg.P.M., whim, J.W.C., Rrag FD.. W- ED.. A&pw&i, PA,OdZidimki, GA, 1993, . AkupwinOrrnlrndSaoWrcouaJltioDit~mdoftheY~Dyu evmt: Nature (London). v. 362, p. 527429. Beiede, B.D., 1996, Put ~~ of the KdLake Am: Wpy, Syncrude camd& Ltd.

Baqpmb L., d Ed,M., 1986, Chcldal hdysb, in Bwglund, BE., ed., d..k

of Holooene P~~ECOIOB~and Phydrology: - - Chichester, John Wdey & Sons, Ltd., p. 423-451. Bjorck, S., Kromer, B., Johnsen, S.. Badce, 0.. Hmmdund, D., LandrN. G., Po~at.G.. Ramumq T.L., WowB., Hum#, C.U., ud Splrk, M., 19%. Synchronized Ternmid-Atmospheric WrlRecords Around the North Atlantic: Science, v. 274, p. 1155-1 160. C)uiwU.W., 1995, PrlynoIow ud Sdhmt~logyof the Amorc B- Daunuk - An InvcStjgation of Late wcichrdiur ud HOI& Luwtrinc Scdimmts, Fm

Clultc, AH., 1981, Thc Fdnmtat Mdwa of c.Ndr: Ottrm Ndod Museum of Sciences, 446 p.

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Ed- T.W.D., Buhry, W.M., Elgood, RJ., md TiH.B.. 1994, An Improved N-tube Pyrolysis Method br Oxygen lrotope AnJyris of Orgrnic Matter and WmChdd Gdogy, v. 1 14, p. 17% 183.

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Jackmn, L.E., 1980, OLdJ Hirtoy rad Stntjpaphy of the Alberta Portion of the KuunuldrWraPortionof~~hka~~:cuudi.aJoumJof Euth S~~CIIC~S,v. 17, p. 459477.

Jackson, L.E., 1986, Comments on "P~10gyud PJwogeognphy New Cochnn. Al- Cuudr, Just After tht Lut w~rHigh Stud of Ghdrl Lake Calgary": Prlrmgeognphy, P~limrtolow,Pdu!oew1ogy, v. 55, p. 79-94.

Kul~m,E.T., 1988, Soil Devdopmerrt in Qwtenury Olrctl Deposits, Waterton Park a Southwesrem Alberta: Geognphie Physique d Qurtenrrire, v. 42, p. 147- 162, Korlsbom, E.T., 1990, Rclict PdplreiJ Futures East of Wuaton-Glrcier Parks, Alberta and Montuy urd Their PJ wchatk Significance: Pmnrhrost ad Paiglrcial V. 1, p. 221-234. Kw,MS., ud Lucbnm. B.H., 1987, A MId-Hoicxene Vegetational and Climatic Record From the Subalpine Zone of the Wgm Valley, Jasper National Puk,

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Wrlliun#,n, D., Trieb, M., Dtnnrti, B., Icok. M,and Thoumy, N., 1993, Equuorhl adendon of the Younger Dyu Em:Rock magdc evidence fiom Lake bhpdi (Km): Olokl d PmCbgq v. 7. p. 235-242. 10.2.1 ResuItS A vibncore taken fiom Beaver Mina Me, located in the fbothills of southern Albertr at 1464 m as.1.. 20 km swthwat of the town of BumMina mg. 2.1) was acunined in the field ud, bucd on the absam ofh(rtunr teph deemed too young to be of interest to this study.

10.2.2 lnterpn,t8tb Thtcmhm~~~ewunoto~cnat~tok~hthis~, andbeauscnogLcirl~wacencaunaal,itcmrotkhrrwnwithcauintyif the entire We recod wu obtrincd, However, the rbrerrc of Mamma teph in the core sugoertr that the lakt may not have foduntil the middle Holocene, when inaewd precipitation in the NeuglaciPl began to aggpde the alluvial bn which dams the lake. An alternative acpluution for the absence of Mrpunr tqhn is that the lake simply dried out in the crrfy Holocate, forming hrdpm which stopped the vibflco~gsystem and pmented coUection of the entire Holmrecord.. 10.3.1 RBsuIYS Tbrrtcorrrwgatrk~11Iiomvrriau~01umr~~.inthcfloorofthe eut and of Sibkld Pur, Kanumk Count~~a! -1400 m rrl. (Fig. 2.1). Two ofthe ~~acr~enthalyof~mdhdmtnocofthe~tephra,whikr tbirdaorr,t~it~nokfrtrrn~~insombMino@cd in the lower 20 an of Cole.

NOW of du tlvac CO~COII~~ h.wn the bogs in the base of Sibbdd PUS contrind bhama tephrr. rugeenL,g the bogs are younger than 6734 BP. The late fodonofdwr bogs myba rttrikrtrbk to middle or late Holocene rllgndaion of du Powdafbce Creek alluvial fhn, located at the urnad of the pur, which appeur to k blocking these wehds. If nta wat dlowod to flow unimpeded through Sibbdd Cndr, what is now r bog would have simply beem a stmm bed prior to damming by the fhn, r su~estionsupported by the prrrarce of rud in the base of one of the three corn.

Pilot Me is r small, 3 m deep lake Wedin tk montane eca-region on the north side of tht Bow VSsy. 4 km muhast of Jdndon Crnyon (Fie. 2.1). ford in a depression in r luge arth8ow. Multiple wincorn were taken fkom various sites in the UC,ud tJe 10- core -1) wm split ad lomd This care ends immediately Wow the M&ZUMteplua, provim r hihgage for the formation of the lobe of the arth Bow upon which Pilot Wre is loatd, but rot addigBr enough back in time to be of interest in this study.

10.4.1 Results The core which wu adyd(PLLI) contains dvegynja hmthe base to the top of the con (355 an), with Mam~tephn located 10 an above the base of the core. Although the ma b actmndy shdl-rich, oo muxofioaril aunts war conducted on this core, nor were TOC, TC or my isotope rarlywr.

~the~femfd~PElotWuoalyUKtGndrlkokto~dy pre-~time,thecmeisnotofL*aa*tothbQdy. Tbc~ofhzmu t~h.llarr~~ofthacaadog,ho*rava,ravttoplres1~&eof6734BP on the a,ge of~~ofthelakeand palPpr dm ontherdivityofthe earth flow in wfiichitisfm. Becawenon-ku&nesedimenr~not~itc~latb said with that thc age ofthe lake is close to that ofthe Maunr tephn, however 1 corn taken in Pilot Wra seemed to encounter large pebble or cobble sized materid where puutmtionhdted.

Hakrt Lake is loated in the bottom of the Bow VJky. at 1617 m ad.. 10 bn northwest of Wre Louise Junction wig 2.1). Six attanpa were mde to obtain r core, however dwiq the bnt 5 attempts, the vi'bncore tube hit bedrock immediateIy upon hvration through the hole in the lake ice. By moving to r vuiety of sita in the lake, a 5 m con was amtdlyartmaad from 8 m of wWr @ERBLI).

10.5.2 intwpmtatbn Although the record fmm Herkit Lake was not lone enough to be used in this study, the oumaws encounters with large mck in the base ofthe lake before a core was 10.6 LVYnrck Lake Altnde I& lies. at 1647 m, in the subalpine zone of Vmnilion Pass (Fig. 2.1). A 1.8 m vibllcoft (ALT1) was ukar in 3 m of water, born the appmrdmrte center of the 3d lowest Wre in r chain of 6 Ma. Two other corn were Wen, but covered r shorter paid oftime than ALTI md were not mrlyrcd.

10.6.1 ResuIYs Though the cure prrrancd in this aection had the longest record of the three corn t9ken,~r~~0doo~in~~onlyadandrufuuimmedirt~pact-~timc (Fig. 10.1). The mire con (0-180an) codsb ofgvnia intempted fian 7 to 12 an by the Mamma tcphn and &om 85 to 86 cm by the Bridge River teph R~Y~9- macrofouilsada throughmost ofthe core, with hcfead valve uMtr 8t 10 an (11.1 VdvdlOO a), 50 an (1 1.1 vrlvdl00 cc) ud 140 an (1 1.1 nlvcr/100 cc). W~thtwoaCcpions,TOCvrl~dimb~~12%uthebucofthecore to 3Wh rt the top (Fig. 10.1). Tbac are slight inarw in TOC at 90 tnd 140 cm to 55 and 46 96, mpmively. TC values rednsteady throu#hout the core, hcreashg slightly &om 45 9i rt the but to SO 96 at the top. There ue two spikes in TC, comesponding to inctused TOC in inteMls 90 ud 140 an. Carbon isotope data (Fig. 10.1) were memad on the orpudc Wonof the core horn the base to the top, however since this core does not mend into tkPleistocene, there is no pre-Holocene standard with which to compare, consequently these data will not be hnapmed or desuibed beyond the gnphicrl reprercntrtion in Fim10.1. Altrude Lake

Figure 10.1. Macrof(~sUs,TOC/TC and 6 '% from Altrude Lake.