Voyageurs National Park

by Megan Saunders

http://www.nature.nps.gov/geology/inventory/publications/reports/voya_gre_rpt_view.pdf

Voyageurs National ParkVoyageurs National Park

Interest in protecting the area Interest in protecting the area since 1891since 1891

Established as Established as a national park a national park in 1975in 1975

Named for Named for historic French-historic French-Canadian Canadian voyageursvoyageurs

Location of VoyageursLocation of Voyageurs

http://nps.seeamerica.org/maps/mn.gifhttp://nps.seeamerica.org/maps/mn.gif

Voyageurs National ParkVoyageurs National Park

http://www.us-national-parks.net/images/voya.jpghttp://www.us-national-parks.net/images/voya.jpg

Geologic History of VoyageursGeologic History of Voyageurs

Contains some of the oldest rocks in Contains some of the oldest rocks in North America (Archean aged)North America (Archean aged)

Algoman OrogenyAlgoman Orogeny– Formed by repeated collisions of isolated Formed by repeated collisions of isolated

areas of crustareas of crust– Subduction created volcanic island arcsSubduction created volcanic island arcs– Later in Orogeny, intrusion of granitic Later in Orogeny, intrusion of granitic

plutonsplutons

Geologic History of Voyageurs Geologic History of Voyageurs

In the In the Proterozoic, Proterozoic, isolated crustal isolated crustal regions regions accreted into accreted into one large cratonone large craton

Voyageurs on Voyageurs on Canadian ShieldCanadian Shield

http://www.kettlefallshotel.com/aerilalake.jpg

Geologic History of VoyageursGeologic History of Voyageurs

Craton covered Craton covered by inland seas by inland seas in early in early PaleozoicPaleozoic

Exposure and Exposure and erosion during erosion during late Paleozoic, late Paleozoic, Mesozoic, and Mesozoic, and CenozoicCenozoic

http://www.destination360.com/north-america/us/minnesota/images/s/voyageurs-national-park.jpg

Geologic History of VoyageursGeologic History of Voyageurs

Glaciations in PleistoceneGlaciations in Pleistocene– Most recent ended about 10,000 years Most recent ended about 10,000 years

agoago Glacial scouring Glacial scouring

– Lake formationLake formation– Glacial striationsGlacial striations– PolishingPolishing

Glacial depositsGlacial deposits– Lake formationLake formation– Till and moraine depositsTill and moraine deposits

http://www.usatravelpal.com/images/states/minnesota/voyageurs-national-park.jpg

Stratigraphic Column of VoyageursStratigraphic Column of Voyageurs

http://www.ux1.eiu.edu/~cfrbj/parks/voya/Voyastarcol4.pdf

Archean

Current Geology of VoyageursCurrent Geology of Voyageurs

Superior ProvinceSuperior Province– Sub-provinces:Sub-provinces:

Wabigoon Sub-provinceWabigoon Sub-provinceQuetico Sub-provinceQuetico Sub-provinceWawa Sub-provinceWawa Sub-province

– Fault Zones:Fault Zones:Rainy Lake-Seine River Rainy Lake-Seine River

Fault ZoneFault ZoneVermillion Fault ZoneVermillion Fault Zone

http://www.nature.nps.gov/geology/inventory/publications/reports/voya_gre_rpt_view.pdf

Current Geology of VoyageursCurrent Geology of Voyageurs

Erosional and glacial evidenceErosional and glacial evidence– Flat landscapeFlat landscape– Thin soilsThin soils– Glacial erratics Glacial erratics

http://www.nps.gov/voya/index.htm

ReferencesReferences

American Park Network. American Park Network. http://americanparknetwork.com/voyageurs http://americanparknetwork.com/voyageurs

Geologic Resource Evaluations. Geologic Resource Evaluations. http://www2.nature.nps.gov/geology/inventory/gre_publicatihttp://www2.nature.nps.gov/geology/inventory/gre_publications.cfm ons.cfm

Harris, A. G., E. Tuttle, and S. D. Tuttle. 2004. Geology of Harris, A. G., E. Tuttle, and S. D. Tuttle. 2004. Geology of National Parks (6National Parks (6thth edition). Kendall Hunt Publishing edition). Kendall Hunt Publishing Company, Dubuque, IA, 882 p.Company, Dubuque, IA, 882 p.

Kiver, E. P. and D. V. Harris. 1999. Geology of U.S. Parklands Kiver, E. P. and D. V. Harris. 1999. Geology of U.S. Parklands (5(5thth edition). John Wiley and Sons, Inc., New York, NY, 902 edition). John Wiley and Sons, Inc., New York, NY, 902 p.p.

NPS Explore Geology. NPS Explore Geology. http://www2.nature.nps.gov/geology/tour/http://www2.nature.nps.gov/geology/tour/

USGS Geology of National Parks. USGS Geology of National Parks. http://wrgis.wr.usgs.gov/parkshttp://wrgis.wr.usgs.gov/parks

Rocky Mountain Rocky Mountain National ParkNational Park

Emily VanWykEmily VanWyk

Rocky Mountain Rocky Mountain National Park National Park (ROMO) was (ROMO) was established established January 26, January 26, 1915 with the 1915 with the passing of the passing of the Rocky Mountain Rocky Mountain National Park National Park ActAct

In 1976 the In 1976 the park was park was designated a designated a biosphere biosphere reservereserve

ROMO is located in the North-Central part of ROMO is located in the North-Central part of Colorado on the Front RangeColorado on the Front Range

The Front Range is on the Continental Divide, The Front Range is on the Continental Divide, and is the furthest east part of the Rockiesand is the furthest east part of the Rockies

Called the “roof” of theCalled the “roof” of the

Rockies, as the some of the Rockies, as the some of the

highest peaks in the Rockies highest peaks in the Rockies

are found here, including a are found here, including a

Handful over 14,000 feet aboveHandful over 14,000 feet above

sea level.sea level.

Basement Crystalline RocksBasement Crystalline RocksPrecambrianPrecambrian

The oldest rocks are Precambrian, deposited approximately The oldest rocks are Precambrian, deposited approximately 1800 million years ago in a marine environment.1800 million years ago in a marine environment.

Shale, sandstone, and carbonates, were interbedded with Shale, sandstone, and carbonates, were interbedded with volcanics.volcanics.

Once lithified, these were metamorphosed into crystalline Once lithified, these were metamorphosed into crystalline schists and gneisses which were intruded by massive schists and gneisses which were intruded by massive granitic magma during mountain building.granitic magma during mountain building.

Late Precambrian was a long, intense period of mountain Late Precambrian was a long, intense period of mountain building and regional metamorphism from intrusions building and regional metamorphism from intrusions

Silver Plume GraniteSilver Plume GranitePrecambrianPrecambrian

A huge batholith, 30 miles across, emplaced itself within A huge batholith, 30 miles across, emplaced itself within these gneisses and schists. This is the Silver Plume granite, these gneisses and schists. This is the Silver Plume granite, and outcrops in much of the eastern side of the park.and outcrops in much of the eastern side of the park.

This granitic batholith contains radioactive materials which This granitic batholith contains radioactive materials which allow for precise dating. The formation was intruded 1450 allow for precise dating. The formation was intruded 1450 million years before present.million years before present.

http://www.cliffshade.com/colorado/rmnp/rmnp01.jpghttp://www.cliffshade.com/colorado/rmnp/rmnp01.jpg

Creation of Ancestral RockiesCreation of Ancestral Rockies The PaleozoicThe Paleozoic

Precambrian uplands were eroded, and Precambrian uplands were eroded, and Paleozoic seas moved over what is now Paleozoic seas moved over what is now the park. Marine sediments were laid the park. Marine sediments were laid down.down.

The region uplifted in the Pennsylvanian, The region uplifted in the Pennsylvanian, creating the Ancestral Rockies.creating the Ancestral Rockies.

These were soon leveled by erosion in the These were soon leveled by erosion in the Mesozoic when seas transgress.Mesozoic when seas transgress.

Laramide OrogenyLaramide OrogenyCretaceousCretaceous

The Cretaceous marks the last The Cretaceous marks the last time the sea advanced on the land time the sea advanced on the land in the park. in the park.

North America plate and Pacific North America plate and Pacific plate collided at the end of the plate collided at the end of the Cretaceous, leading to differential Cretaceous, leading to differential compression, fault blocks, and compression, fault blocks, and thrust-faulting.thrust-faulting.

Creation of the Front Range Creation of the Front Range TertiaryTertiary

More uplift, erosion, and volcanism. More uplift, erosion, and volcanism. Uplifts primarily along old faults, elevation Uplifts primarily along old faults, elevation

increased. Front Range rises as a series of increased. Front Range rises as a series of stepssteps

Movement possibly due to isostatic Movement possibly due to isostatic compensation.compensation.

By Quaternary, the Front Range as we By Quaternary, the Front Range as we know it in height was in place.know it in height was in place.

The Front Range illustrates thrust faulting and folding, as well as The Front Range illustrates thrust faulting and folding, as well as huge, faulted anticline mountains. High angle thrust faults huge, faulted anticline mountains. High angle thrust faults created these features, along with isostatic adjustment. There created these features, along with isostatic adjustment. There are major faults on both sides of the range. Extensive activity are major faults on both sides of the range. Extensive activity shows the park is found on the leading edge of the continent.shows the park is found on the leading edge of the continent.

It is hard to understand the formation of the Rockies, as they are It is hard to understand the formation of the Rockies, as they are located far inland, far from the tectonic boundary. located far inland, far from the tectonic boundary.

Most geologists think they were created by an extremely low Most geologists think they were created by an extremely low angle subduction, which let crust push under the continental angle subduction, which let crust push under the continental crust all the way inland to push up the mountains.crust all the way inland to push up the mountains.

Extensive thrusting built up the huge mountains.Extensive thrusting built up the huge mountains.

GlaciationGlaciationPleistocenePleistocene

Early glaciation included two main Early glaciation included two main advances 1.2 million years ago.advances 1.2 million years ago.

Most traces of these glacial advances Most traces of these glacial advances were destroyed by later glacial were destroyed by later glacial periods. The oldest evidence can be periods. The oldest evidence can be found on the eastern boundary of the found on the eastern boundary of the park.park.

GlaciationGlaciationPleistocenePleistocene

Bull Lake Glaciation, brutal and long lasting, Bull Lake Glaciation, brutal and long lasting, occurred between 300,000 ybp and occurred between 300,000 ybp and 130,000 ybp. 130,000 ybp.

This glacial period deepened basins created This glacial period deepened basins created by earlier glacial periods, and left by earlier glacial periods, and left prominent moraines.prominent moraines.

These moraines are very close together, These moraines are very close together, indicating a slow retreat speed. They are indicating a slow retreat speed. They are similar in size, shape, and type of material.similar in size, shape, and type of material.

Can be found near Shadow Mountain Lake, Can be found near Shadow Mountain Lake, Beaver Meadows, and Moraine Park. Beaver Meadows, and Moraine Park.

GlaciationGlaciationPleistocenePleistocene

Pinedale Glaciation occurred during Pinedale Glaciation occurred during Wisconsonian time. This included three Wisconsonian time. This included three episodes which reached their maximum episodes which reached their maximum approximately 20,000 to 18,000 years ago.approximately 20,000 to 18,000 years ago.

Sculptured the mountains as we know Sculptured the mountains as we know them, making strong ridges and steep them, making strong ridges and steep drop offs. This period is responsible for the drop offs. This period is responsible for the nearly vertical east face of Longs Peak.nearly vertical east face of Longs Peak.

This period was much less intense.This period was much less intense. The last Pleistocene Glacier disappeared The last Pleistocene Glacier disappeared

about 10,000 years ago.about 10,000 years ago.

Post Pleistocene GlaciationPost Pleistocene Glaciation

Neoglaciation began about 3,800 Neoglaciation began about 3,800 ybp.ybp.

Two major advance/retreat series Two major advance/retreat series known.known.

Currently, there is little more than Currently, there is little more than perennial snowfields and glacierets. perennial snowfields and glacierets. These have recently increased in sizeThese have recently increased in size

Glacial FeaturesGlacial Features

Rock-Basin Lake - Cub Lake, East InletRock-Basin Lake - Cub Lake, East Inlet Moraines - Moraine ParkMoraines - Moraine Park Roche Montonnee - Glacial KnobsRoche Montonnee - Glacial Knobs Glacial Pavement - North InletGlacial Pavement - North Inlet U valleys - Fall RiverU valleys - Fall River CirqueCirque Hanging Valley - Hanging ValleyHanging Valley - Hanging Valley

SourcesSources

usgs.gov/parksusgs.gov/parks