Misplaced Pages

#249750

48-630: Grand Portage State Park is on the Minnesota side of the bay, and Pigeon River is on the Ontario side of the bay. This article related to a river in Ontario , Canada is a stub . You can help Misplaced Pages by expanding it . This article about a location in Cook County, Minnesota is a stub . You can help Misplaced Pages by expanding it . This article related to a river or creek in Minnesota

96-515: A cover of till. Interpreting the glacial history of landforms can be difficult due to the tendency of overprinting landforms on top of each other. As a glacier melts, large amounts of till are eroded and become a source of sediments for reworked glacial drift deposits. These include glaciofluvial deposits , such as outwash in sandurs , and as glaciolacustrine and glaciomarine deposits, such as varves (annual layers) in any proglacial lakes which may form. Erosion of till may take place even in

144-476: A deep gorge through the shale and greywacke of the Rove Formation. The U.S. Geological Survey estimated that 3,200 US gallons (12,000 L) of water flow over High Falls every second. On sunny days rainbows are often visible in the falls' mist. In winter ice can form on the falls 10 to 20 feet (3 to 6 m) thick, but water continues to flow underneath. A mixed hardwood forest covers most of

192-466: A higher water content behave more fluidly, and thus are more susceptible to flow. There are three main types of flows, which are listed below. In cases where till has been indurated or lithified by subsequent burial into solid rock, it is known as the sedimentary rock tillite . Matching beds of ancient tillites on opposite sides of the south Atlantic Ocean provided early evidence for continental drift . The same tillites also provide some support to

240-483: A historically important portage on a fur trade route between the Great Lakes and inland Canada. This 8.5-mile (13.7 km) path as well as the sites of historic forts at either end are preserved in nearby Grand Portage National Monument . The state park, held by the surrounding Grand Portage Indian Reservation and leased to the state of Minnesota for $ 1 a year, is the only U.S. state park jointly managed by

288-476: A later event formed northwest-to-southeast trending dikes . Together they are known as the Logan Intrusions after Canadian geologist William Edmond Logan . From 2 million years ago to 10,000 years ago a series of glacial periods repeatedly covered the region with ice, scouring the bedrock and scooping out a great basin. The hard diabase intrusions were more resistant to the ice and survived as

336-525: A network of ridges. At the end of the last glacial period the basin filled with meltwater, forming Glacial Lake Minong , Lake Superior's precursor. Freed from the weight of the glaciers, the surrounding land gradually rose. This post-glacial rebound plus draining of the lake caused the shoreline to recede, first exposing the ridges of the park as islands, then leaving the entire area above water. The stages of shoreline recession are revealed by lake terraces composed of beach gravels. The sharp drop from

384-558: A state and a Native American band. It is also the only Minnesota state park not owned by the state. During the Paleoproterozoic era from 2.2 to 1.9 billion years ago, mud and muddy sand accumulated on the bed of a shallow sea. These sediments compacted into layers of shale and graywacke . Dubbed the Rove Formation , they are among the oldest unmetamorphosed sedimentary rock on earth. 1.1 billion years ago

432-560: A state and an Indian tribe, and the only Minnesota state park not owned by the state. Since the land was within the Grand Portage Indian Reservation, the state park bill was drafted with several provisions establishing a novel collaboration. Legislation establishing the park passed unanimously in both houses of the Minnesota Legislature in 1989. The Parks and Trails Council sold the land to

480-400: Is unsorted glacial sediment . Till is derived from the erosion and entrainment of material by the moving ice of a glacier . It is deposited some distance down-ice to form terminal , lateral , medial and ground moraines . Till is classified into primary deposits, laid down directly by glaciers, and secondary deposits, reworked by fluvial transport and other processes. Till

528-595: Is a stub . You can help Misplaced Pages by expanding it . Grand Portage State Park Grand Portage State Park is a state park at the northeastern tip of the U.S. state of Minnesota , on the Canada–United States border . It contains a 120-foot (37 m) waterfall , the tallest in the state (though it is on the border with Canada and thus partially in Ontario ), on the Pigeon River . The High Falls and other waterfalls and rapids upstream necessitated

SECTION 10

#1732771915250

576-510: Is a form of glacial drift , which is rock material transported by a glacier and deposited directly from the ice or from running water emerging from the ice. It is distinguished from other forms of drift in that it is deposited directly by glaciers without being reworked by meltwater. Till is characteristically unsorted and unstratified , and is not usually consolidated . Most till consists predominantly of clay, silt , and sand , but with pebbles, cobbles, and boulders scattered through

624-417: Is likely eroded from bedrock rather than being created by glacial processes. The sediments carried by a glacier will eventually be deposited some distance down-ice from its source. This takes place in the ablation zone , which is the part of the glacier where the rate of ablation (removal of ice by evaporation, melting, or other processes) exceeds the rate of accumulation of new ice from snowfall. As ice

672-705: Is removed, debris are left behind as till. The deposition of glacial till is not uniform, and a single till plain can contain a wide variety of different types of tills due to the various erosional mechanisms and location of till with respect to the transporting glacier. The different types of till can be categorized between subglacial (beneath) and supraglacial (surface) deposits. Subglacial deposits include lodgement, subglacial meltout, and deformation tills. Supraglacial deposits include supraglacial meltout and flow till. Supraglacial deposits and landforms are widespread in areas of glacial downwasting (vertical thinning of glaciers, as opposed to ice-retreat. They typically sit at

720-556: The North American Plate began to crack in the middle, and lava flowed out of this Midcontinent Rift System creating the distinctive basalt of Lake Superior 's North Shore (and Interstate Park to the south). In what is now Grand Portage State Park, upwelling magma did not reach the surface but intruded into fractures in the Rove Formation, cooling more slowly into diabase rather than basalt. One set of intrusions formed northeast-to-southwest trending sills while

768-563: The Precambrian Snowball Earth glaciation event hypothesis. Tills sometimes contain placer deposits of valuable minerals such as gold. Diamonds have been found in glacial till in the north-central United States and in Canada. Till prospecting is a method of prospecting in which tills are sampled over a wide area to determine if they contain valuable minerals, such as gold, uranium, silver, nickel, or diamonds, and

816-512: The U.S. Forest Service to help create Superior National Forest and the Boundary Waters Canoe Area Wilderness , agreed to sell 178 acres (72 ha) and donate a further 129 acres (52 ha). The Parks and Trails Council raised Johnson's asking price of $ 250,000 through contributions from individuals and foundations and completed the sale in 1988. The park is the only one in the country co-managed by

864-434: The entrainment by the moving ice of previously available unconsolidated sediments. Bedrock can be eroded through the action of glacial plucking and abrasion , and the resulting clasts of various sizes will be incorporated to the glacier's bed. Glacial abrasion is the weathering of bedrock below a flowing glacier by fragmented rock on the basal layer of the glacier. The two mechanisms of glacial abrasion are striation of

912-580: The 1890s the Alger, Smith and Company began logging on both sides of the border. In 1899 a series of sluices, dams, and flumes were built to float the logs safely around the waterfalls and gorges; remains of the wooden timber slide around the High Falls are still visible on the Canadian side. The Pigeon River Lumber Company began operations in 1900 and within a few years the two companies had stripped

960-555: The Grand Portage Band. The state park is located at the northern terminus of scenic Minnesota Highway 61 . The park's seasonal visitor center was replaced in September 2010 with a 5,800-square-foot (540 m ) combination visitor center, state travel information center, and highway rest area . It is staffed by Grand Portage Band members and contains exhibits interpreting Ojibwe life. The new facility complements

1008-847: The Grand Portage and along routes in the interior, the future Grand Portage State Park remained largely undeveloped. The region was claimed by the French, then passed to the British following the French and Indian War under the 1763 Treaty of Paris . Following the independence of the United States the Arrowhead Region of Minnesota was disputed with British Canada. In 1842 the Webster–Ashburton Treaty finally settled

SECTION 20

#1732771915250

1056-623: The Minnesota Department of Natural Resources (DNR) for $ 316,000, an amount well under its appraised value. The DNR then began the complicated process of transferring the land to the Bureau of Indian Affairs , which would hold it in trust for the Grand Portage Band of Chippewa, who in turn would lease the park back to the DNR for $ 1 a year. Grand Portage State Park finally opened to the public in September 1994. It took so long to finalize

1104-464: The Pigeon River as the international border. When the U.S. began negotiating the 1854 Treaty of La Pointe with the region's Ojibwe, hard-bargaining Grand Portage band leaders such as Adikoons secured a reservation within their traditional territory instead of being displaced west. The future state park was originally part of the reservation, but became tax-forfeit and was bought by whites. In

1152-556: The Webster-Ashburton Treaty. In winter all of the trails are open for snowshoeing. Grand Portage State Park is developed for day-use only. The closest camping is in Ontario's adjacent Pigeon River Provincial Park or in the unincorporated community of Grand Portage, Minnesota . The park emphasizes interpretation of Ojibwe cultural heritage, as a counterpoint to fur trade and natural history interpretation at nearby parks. Many park employees have been members of

1200-692: The area, expanding as middlemen in the fur trade with the French. The Pigeon River, an otherwise useful route from the Great Lakes to inland Canada, was impassable over its last 22 miles (35 km) due to the waterfalls and rapids. To avoid this stretch early native inhabitants developed a footpath known as Kitchi Onigaming in the Ojibwe language , a name translated by French commercial explorers as Grand Portage , or "the Great Carrying Place." While busy outposts sprang up at either end of

1248-450: The bedrock by coarse grains moved by the glacier, thus gouging the rock below, and polishing of the bedrock by smaller grains such as silts. Glacial plucking is the removal of large blocks from the bed of a glacier. Much of the silt in till is produced by glacial grinding, and the longer the till remains at the ice-bedrock interface, the more thoroughly it is crushed. However, the crushing process appears to stop with fine silt. Clay in till

1296-498: The clasts dipping upstream. Though till is generally unstratified, till high in clay may show lamination due to compaction under the weight of overlying ice. Till may also contain lenses of sand or gravel , indicating minor and local reworking by water transitional to non-till glacial drift. The term till comes from an old Scottish name for coarse, rocky soil. It was first used to describe primary glacial deposits by Archibald Geikie in 1863. Early researchers tended to prefer

1344-413: The difficulties in accurately classifying different tills, which are often based on inferences of the physical setting of the till rather than detailed analysis of the till fabric or particle size. Subglacial lodgement tills are deposits beneath the glacier that are forced, or "lodged" into the bed below. As glaciers advance or retreat, the clasts that are deposited by the ice may have a lower velocity than

1392-424: The end of a gentle 0.5-mile (0.8 km) paved trail and boardwalk. Three wooden decks provide different angles to view the falls. A further 3.5 miles (5.6 km) of hiking trail leads to the 30-foot (9 m) Middle Falls and provides distant views of Lake Superior and Isle Royale from hilltops. A 0.2-mile (0.3 km) path leads from the park office through the picnic area to a historic marker commemorating

1440-410: The glacier. Many of the clasts are faceted, striated, or polished, all signs of glacial abrasion . The sand and silt grains are typically angular to subangular rather than rounded. It has been known since the careful statistic work by geologist Chauncey D. Holmes in 1941 that elongated clasts in tills tend to align with the direction of ice flow. Clasts in till may also show slight imbrication , with

1488-411: The glacier. Since the rate of deposition is controlled by the rate of basal melting, it is worth considering the factors that contribute to melting. These can be the geothermal heat flux, frictional heat generated by sliding, ice thickness, and ice-surface temperature gradients. Subglacial deformation tills refer to the homogenization of glacial sediments that occur when the stresses and shear forces from

Pigeon Bay - Misplaced Pages Continue

1536-401: The glacier. These consist of clasts and debris that become exposed due to melting via solar radiation. These debris are either just debris that have a high relative position on the glacier, or clasts that have been transported up from the base of the glacier. Debris accumulation has a feedback-loop relationship with melting. Initially, the darker colored debris absorb more heat and thus accelerate

1584-403: The ice itself. When the friction between the clast and the bed exceeds the forces of the ice flowing above and around it, the clast will cease to move, and it will become a lodgement till. Subglacial meltout tills are tills that are deposited via the melting of the ice lobe. Clasts are transported to the base of the glacier over time, and as basal melting continues, they are slowly deposited below

1632-595: The land deal that another entire Minnesota state park, Glendalough , had been authorized, developed, and dedicated in the meantime. As a result of the COVID-19 pandemic in the United States , the Minnesota Department of Natural Resources temporarily closed Grand Portage State Park on April 10, 2020 at the request of the Grand Portage Band of Lake Superior Chippewa . The High Falls is at

1680-578: The land of salable timber and moved away, leaving the area afflicted with unemployment, forest fires, and poor hunting. In the early twentieth century a remote fishing resort was located within the future park. In the 1930s plans were made to route Highway 61 across the Pigeon River at the High Falls, but conservation groups like the Izaak Walton League opposed the plan and the bridge and border crossing were ultimately built farther downstream in 1966. The land adjoining High and Middle Falls

1728-483: The large travel center in Gooseberry Falls State Park , bookending the eight state parks along Minnesota's North Shore. Grand Portage State Park follows two miles (3.2 km) of the Pigeon River, which marks the Canada – United States border. The U.S. Customs border checkpoint is visible from the park entrance and in fact sits within the park's authorized boundaries. In September 2008

1776-650: The melting process. After a significant amount of melting has occurred, the thickness of the till insulates the ice sheet and slows the melting process. Supraglacial meltout tills typically end up forming moraines. Supraglacial flow tills refer to tills that are subject to a dense concentration of clasts and debris from meltout. These debris localities are then subsequently affected by ablation . Due to their unstable nature, they are subject to downslope flow, and thus named "flow till." Properties of flow tills vary, and can depend on factors such as water content, surface gradient, and debris characteristics. Generally, flow tills with

1824-470: The moving glacier rework the topography of the bed. These contain preglacial sediments (non glacial or earlier glacial sediments), which have been run over and thus deformed by meltout processes or lodgement. The constant reworking of these deposited tills leads to a highly homogenized till. Supraglacial meltout tills are similar to subglacial meltout tills. Rather than being the product of basal melting, however, supraglacial meltout tills are imposed on top of

1872-415: The occasional coyote and timber wolf . Waterfowl and raptors such as osprey frequent the Pigeon River, which also attracts walleye , northern pike , and rainbow smelt for their spring spawning . At the beginning of historical times Grand Portage and the Pigeon River lay along the border between Dakota land to the south and Cree to the north. By the early eighteenth century Ojibwe arrived in

1920-411: The park's rugged terrain defeated a rare illegal border crossing . Two Eastern Europeans were dropped off by a paid accomplice on the Canadian side of the border and waded across the Pigeon River near Middle Falls. They were supposed to hike through the park and rejoin their accomplice—who drove around through the checkpoint—in the parking lot. Instead the rough terrain exhausted them and they fled from

1968-655: The park, chiefly paper birch and quaking aspen with occasional white spruce , eastern white pine , balsam fir , northern white cedar , poplar, and black ash . A more boreal forest appears on ridges and slopes, with black spruce joining the previously listed conifers intermixed with additional birch and aspen. Bottomlands near the river support black and green ash as well as white cedar, white spruce, and yellow birch . Mammalian species of this park include white-tailed deer , moose , Canadian lynx , black bear , red fox , porcupine , pine marten , river otter , beaver , snowshoe hare , skunk , and red squirrel with

Pigeon Bay - Misplaced Pages Continue

2016-464: The subglacial environment, such as in tunnel valleys . There are various types of classifying tills: Traditionally (e.g. Dreimanis , 1988 ) a further set of divisions has been made to primary deposits, based upon the method of deposition. Van der Meer et al. 2003 have suggested that these till classifications are outdated and should instead be replaced with only one classification, that of deformation till. The reasons behind this are largely down to

2064-539: The surrounding land to the lake produces the numerous waterfalls for which the North Shore is famous. The Pigeon River cut its course through soft sediments and glacial till . However it intersected two erosion-resistant dikes which created the High Falls and farther upstream the Middle Falls, which cascades 10 feet (3 m) then drops a further 20 feet (6 m). Below the High Falls the river has carved

2112-412: The term boulder clay for the same kind of sediments, but this has fallen into disfavor. Where it is unclear whether a poorly sorted, unconsolidated glacial deposit was deposited directly from glaciers, it is described as diamict or (when lithified ) as diamictite . Tillite is a sedimentary rock formed by lithification of till. Glacial till is mostly derived from subglacial erosion and from

2160-491: The till. The abundance of clay demonstrates lack of reworking by turbulent flow, which otherwise would winnow the clay. Typically, the distribution of particle sizes shows two peaks (it is bimodal ) with pebbles predominating in the coarser peak. The larger clasts (rock fragments) in till typically show a diverse composition, often including rock types from outcrops hundreds of kilometers away. Some clasts may be rounded, and these are thought to be stream pebbles entrained by

2208-413: The top of the stratigraphic sediment sequence, which has a major influence on land usage. Till is deposited as the terminal moraine , along the lateral and medial moraines and in the ground moraine of a glacier, and moraine is often conflated with till in older writings. Till may also be deposited as drumlins and flutes , though some drumlins consist of a core of stratified sediments with only

2256-565: The woods toward a nearby duty-free shop in front of Border Patrol officers, who took them into custody and alerted other agents who arrested the waiting driver. Since the High Falls of the Pigeon River is shared with Ontario, the 70-foot (21 m) High Falls on the Baptism River in Tettegouche State Park is often touted as "the highest waterfall entirely within Minnesota." Till Till or glacial till

2304-464: Was purchased as a possible commercial property by Lloyd K. Johnson, a white attorney and land speculator from Duluth , who held onto it for decades. In 1985 a park advocacy group, the Minnesota Parks and Trails Council, suggested complementing Ontario's Pigeon River Provincial Park with a Minnesota state park. Johnson, who in the 1930s and 40s had sold hundreds of thousands of acres to

#249750