Geology of Ontario hiking trails takes you back in time.

Test Post Jasper

-Maligne Valley south of Jasper is a glaciated U-shaped valley 58 km long and 1.5-6.5 km wide
-lake was dammed in northend by end moraine of Pleistocene glacier that flowed from SE to NW
-highest peaks are south end of Maligne Lake (Mt. Brazeau 3470 m, Mt. Monkhead 3211 m), all Ordovician to Devonian 350-600 mya
-east side of valley is steeply dipping limestone Devonian to Mississippian forming sawtooth mountains called Colin Range
-west side is Cambrian & Precambrian quartzite and shales, which are more rounded due to glacier flowing over them

>500 mya: oldest rocks are Precambrian Miette Group, mainly sandstone, quartzite, shales, altered or metamorphosed
-Miette rocks extend from Maligne Lk to north of Jasper

500-600 mya: Gog Fm. sandstone with some conglomerate overlie Miette strata, forming huge cliffs south half of Maligne Lk.
-Gog rocks weather to reddish brown rubble (eg. peak north end of Maligne Lk)
-other Fm. from bottom to top, Titkana, Pika, Arctomys, Lynx, mainly shales and limestones
-limestone forms cliffs while shales are recessive or form benches (Monkhead & Llysfran on southend of lake)
-Pika Fm very colourful red, brown, green shale (Mt. Mary Vaux, Coronet Creek)

450-500 mya: shallow sea with deposits of limestone during late Cambrian early Ordovician
-Chushina Fm forms bench, Sarbach Fm forms 800 ft high cliffs (Maligne Mt. above Mt. Paul SW side of Samson Narrows)

400 mya: uplift and subsequent erosion during Devonian created unconformity, no trace of rocks from late Ordovician or Silurian

375 mya: Late Devonian fossiliferous marine limestones & shales of Fairholme Group
-form rubbly slopes & cliffs on west flank of Maligne Mt and north ridge leading to Mt. Unwin & Charlton
-Fairholme Gr. overlain by lighter coloured Palliser Fm limestone which forms massive cliffs and peaks (Samson Peak, Colin Ridge)

360 mya: Mississippian marine carbonate rocks (Leah Peak, ridge flanking Medicine Lake and Roche Bonhomme)
-lower Banff Fm is dark, shaly and recessive
-upper Rundle Gr is light coloured and cliff forming

250-360 mya: near shore sediments deposited when region was slightly above and slightly below sea level (Pensylvannia to Permian)
-represented by whitish chert and sandstone of the Rocky Mountain Fm

Please follow and like us:

Leave a comment

Your email address will not be published. Required fields are marked *