a brief history of the lake iroquois shoreline in toronto (july 2012)

8/18/2019 A Brief History of the Lake Iroquois Shoreline in Toronto (July 2012)

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A brief history of the Lake Iroquois shoreline in Toronto

Posted by Chris Bateman / JULY 14, 2012

As we've mentioned in previous posts, Toronto is home to some m!in" ntur# $etures % the Toronto

&s#ndsnd the mi"hty on, (umber nd )ou"e rivers to nme $ew % but we hven't tou*hed on the

history o$ the most obvious nd in$#uenti# o$ them ##+ Le -ntrio.

ost Torontonins re $mi#ir with the windin" venport )od nd the bse o$ the steep in*#ine it

$o##ows, but not everyone nows tht the ro*y out*rop south o$ t. #ir mrs the $ormer shore#ine o$

Le &rouois, proto%version o$ Le -ntrio tht be"n to re*ede t the end o$ the #st i*e "e #evin"

behind the *rborou"h 3#u$$s nd other notb#e $etures o$ the *ity.

Le -ntrio, to use its *urrent nme, hs si"ni$i*nt#y $#u*tuted in si!e over the #st sever# thousnd

yers due to the s#ow retret o$ #obe o$ the Lurentide &*e heet, mssive *ontinent o$ i*e tht on*e

*overed most o$ nd nd prts o$ the United ttes. The #nd Toronto is bui#t on tody hs t vrioustimes been under 0 metres o$ wter nd strnded we## in#nd.

The utter#y vst, sprw#in" Lurentide % up to two mi#es thi* in prts o$ northern 5uebe* % p#u""ed the

int Lwren*e )iver v##ey nd *reted "int depressions in the "round. As the i*e be"n to retret in the

$*e o$ risin" "#ob# tempertures, me#twter % *hnne##ed by n*ient rivers % be*me trpped in "ret #nd

bsins nd $ormed #r"e #es, the most ester#y o$ whi*h ws Le &rouois.

http://www.blogto.com/author/chrisbatemanhttp://www.blogto.com/city/2012/05/how_a_long_sandy_beach_became_the_toronto_islands/http://www.blogto.com/city/2012/05/how_a_long_sandy_beach_became_the_toronto_islands/http://www.blogto.com/city/2012/04/that_time_when_the_don_river_was_straightened/http://en.wikipedia.org/wiki/Laurentide_ice_sheethttp://www.blogto.com/city/2012/05/how_a_long_sandy_beach_became_the_toronto_islands/http://www.blogto.com/city/2012/05/how_a_long_sandy_beach_became_the_toronto_islands/http://www.blogto.com/city/2012/04/that_time_when_the_don_river_was_straightened/http://en.wikipedia.org/wiki/Laurentide_ice_sheethttp://www.blogto.com/author/chrisbateman


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6iew Le &rouois hore#ine in #r"er mp+ https+//www."oo"#e.*om/mps/d/viewer7##849.:0:0;:[email protected]"u2

UBp?

https://maps.google.ca/maps/ms?ie=UTF8&hl=en&oe=UTF8&msa=0&msid=212826687826023083851.0004c4bd2f028fd565bfd&t=m&ll=43.707097,-79.377594&spn=0.173727,0.405121&z=11&source=embedhttps://maps.google.ca/maps/ms?ie=UTF8&hl=en&oe=UTF8&msa=0&msid=212826687826023083851.0004c4bd2f028fd565bfd&t=m&ll=43.707097,-79.377594&spn=0.173727,0.405121&z=11&source=embedhttps://maps.google.ca/maps/ms?ie=UTF8&hl=en&oe=UTF8&msa=0&msid=212826687826023083851.0004c4bd2f028fd565bfd&t=m&ll=43.707097,-79.377594&spn=0.173727,0.405121&z=11&source=embedhttps://www.google.com/maps/d/viewer?ll=43.707097%2C-79.377594&spn=0.173727%2C0.405121&hl=en&t=m&oe=UTF8&msa=0&z=11&source=embed&ie=UTF8&mid=zYxmJ0Aymn2M.khSgau2WUNp8https://www.google.com/maps/d/viewer?ll=43.707097%2C-79.377594&spn=0.173727%2C0.405121&hl=en&t=m&oe=UTF8&msa=0&z=11&source=embed&ie=UTF8&mid=zYxmJ0Aymn2M.khSgau2WUNp8https://www.google.com/maps/d/viewer?ll=43.707097%2C-79.377594&spn=0.173727%2C0.405121&hl=en&t=m&oe=UTF8&msa=0&z=11&source=embed&ie=UTF8&mid=zYxmJ0Aymn2M.khSgau2WUNp8https://www.google.com/maps/d/viewer?ll=43.707097%2C-79.377594&spn=0.173727%2C0.405121&hl=en&t=m&oe=UTF8&msa=0&z=11&source=embed&ie=UTF8&mid=zYxmJ0Aymn2M.khSgau2WUNp8https://maps.google.ca/maps/ms?ie=UTF8&hl=en&oe=UTF8&msa=0&msid=212826687826023083851.0004c4bd2f028fd565bfd&t=m&ll=43.707097,-79.377594&spn=0.173727,0.405121&z=11&source=embedhttps://www.google.com/maps/d/viewer?ll=43.707097%2C-79.377594&spn=0.173727%2C0.405121&hl=en&t=m&oe=UTF8&msa=0&z=11&source=embed&ie=UTF8&mid=zYxmJ0Aymn2M.khSgau2WUNp8https://www.google.com/maps/d/viewer?ll=43.707097%2C-79.377594&spn=0.173727%2C0.405121&hl=en&t=m&oe=UTF8&msa=0&z=11&source=embed&ie=UTF8&mid=zYxmJ0Aymn2M.khSgau2WUNp8https://www.google.com/maps/d/viewer?ll=43.707097%2C-79.377594&spn=0.173727%2C0.405121&hl=en&t=m&oe=UTF8&msa=0&z=11&source=embed&ie=UTF8&mid=zYxmJ0Aymn2M.khSgau2WUNp8


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&rouois ws, very rou"h#y, s*#ed up version o$ Le -ntrio. The shpe o$ the shore#ine, reve#ed by

vrious "eo#o"i*# surveys, ppro@imte#y mt*hes tht o$ tody's #e on#y with s#i"ht#y wider ed"es nd

#on" e@tension t its southest e@tremity into Bew Yor stte. This ws where &rouois drined % over

the Bi"r es*rpment nd down the ohw )iver % insted o$ vi the int Lwren*e s it does tody.

At Toronto, &rouois' wters #pped the bse o$ the hi## north o$ venport )od. Cverythin" south % the

entire downtown tht is % ws on*e t the bottom o$ the #e. A**ordin" to Btur# )esour*es nd, the

wter wou#d hve been deep enou"h to h#$%submer"e the )oy# Yor (ote#. pdin Avenue nd )od

wou#d #ter "et their *orrupted -Dibw nme % ishpadinaa menin" E hi"h hi## or sudden rise in the #ndE

% so *##ed $or the es*rpment #e$t behind by &rouois. s Lom owes its e@pnsive views to the sme

$eture.

>or the most prt, the route is re#tive#y esy to $o##ow. )unnin" west to est, the &rouois shore#ine

sweeps north $rom where unds treet *rosses Ctobi*oe ree to the 3#* ree underpss t the 401.

>rom this norther#y point, eston )od $o##ows the shore#ine b* south to venport )od, *ross the

*ity, to n re ner Pottery )od. A $in# in#nd sweep round Cst Yor ends with the *rborou"h

3#u$$s t the shore#ine Le -ntrio. The mp bove rou"h#y i##ustrtes this.

As the Lurentide &*e heet retreted north, it #e$t si"ni$i*nt depression in the erth's sur$*e ner the

northest *orner o$ Le &rouois. As resu#t, the thwed int Lwren*e v##ey be"n to ##ow #e

wter to es*pe into the At#nti* o*en. Lie sm## pun*ture in swimmin" poo#, the wter #eve# s#ow#y

but drmti*##y dropped in the #e, eventu##y eu#i!in" rou"h#y 20 metres #ower thn it is tody. This

http://www.geologyontario.mndm.gov.on.ca/mndmfiles/pub/data/imaging/P2204/p2204.pdfhttp://www.geologyontario.mndm.gov.on.ca/mndmfiles/pub/data/imaging/P2204/p2204.pdfhttp://www.nrcan.gc.ca/earth-sciences/products-services/mapping-product/geoscape/toronto/6340http://www.geologyontario.mndm.gov.on.ca/mndmfiles/pub/data/imaging/P2204/p2204.pdfhttp://www.geologyontario.mndm.gov.on.ca/mndmfiles/pub/data/imaging/P2204/p2204.pdfhttp://www.nrcan.gc.ca/earth-sciences/products-services/mapping-product/geoscape/toronto/6340


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new, sm##er #e ws nmed F#*i# Le Admir#ty nd "iven seprte identity to &rouois by

"eo#o"ists.

The shore#ine o$ this si"ni$i*nt#y sm##er **umu#tion o$ me#twter is sti## pprent underwter

nd, **ordin" to iipedi, is nown s the Toronto *rp to those who now the #e bed.

#ow#y, the on*e depressed #nd in the northwest tht he#ped drin Le &rouois be"n to rise b* in

#ine with the surroundin" re, stemmin" the outwrd $#ow o$ wter $rom Admir#ty nd *usin" the wter

#eve# to rise on*e "in. Le -ntrio is the end produ*t o$ tht $in# rise.

http://en.wikipedia.org/wiki/Glacial_Lake_Iroquoishttp://en.wikipedia.org/wiki/Glacial_Lake_Iroquoishttp://en.wikipedia.org/wiki/Glacial_Lake_Iroquois


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indin" its wy throu"h the *ity nd round the #e, the &rouois shore#ine is si"ni$i*nt "eo"rphi*#

$eture o$ Toronto, -ntrio nd the stte o$ Bew Yor, nd perhps our most *onspi*uous *onne*tion to

the n*ient #nds*pe tht e@isted be$ore the rriv# o$ humns. &t mi"ht hve been pun*tured nd

smoothed to ##ow "ent#er in*#ine $or sever# north%south streets, but the es*rpment sti## ho#ds swy

over the wy we "et round Toronto.

Photos: City of Toronto Archives

http+//www.b#o"to.*om/*ity/2012/0:/Gbrie$GhistoryGo$GtheG#eGirouoisGshore#ineGinGtoronto/
http://www.blogto.com/city/2012/07/a_brief_history_of_the_lake_iroquois_shoreline_in_toronto/http://www.blogto.com/city/2012/07/a_brief_history_of_the_lake_iroquois_shoreline_in_toronto/http://www.blogto.com/city/2012/07/a_brief_history_of_the_lake_iroquois_shoreline_in_toronto/

a brief history of the lake iroquois shoreline in toronto (july 2012)

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