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35-752: The Oxtongue River is a channel of a former spillway that formed when glacial waters from the Algonquin Highlands melted and flowed to proglacial Lake Algonquin . The Oxtongue River springs inside Algonquin Provincial Park . After this park, the river enters the Oxtongue River-Ragged Falls Provincial Park, where it flows over 2 major waterfalls, the High Falls and Ragged Falls. Then it is crossed by Highway 60 and enters Oxtongue Lake. After

70-492: A Crown Reserve. In the 1960s, it was considered to add this area to the perimeter recreation system program of Algonquin Provincial Park. In 1985, the park was officially created with an original area of 382 hectares (940 acres), and enlarged in 1995 to 507 hectares (1,250 acres) by the addition of 125 hectares (310 acres) around the Oxtongue River Bog Forest. The Oxtongue River-Ragged Falls Provincial Park

105-399: A glacial overspill channel created when the water of a proglacial lake rose high enough to breach the lowest point in the containing watershed. Moraine A moraine is any accumulation of unconsolidated debris ( regolith and rock ), sometimes referred to as glacial till , that occurs in both currently and formerly glaciated regions, and that has been previously carried along by

140-409: A glacier or ice sheet. It may consist of partly rounded particles ranging in size from boulders (in which case it is often referred to as boulder clay) down to gravel and sand, in a groundmass of finely-divided clayey material sometimes called glacial flour . Lateral moraines are those formed at the side of the ice flow, and terminal moraines are those formed at the foot, marking the maximum advance of

175-498: A hazard for zones below. Many natural dams (usually moraines ) containing the lake water have been reinforced with safety dams. Some 34 such dams have been built in the Cordillera Blanca to contain proglacial lakes. Several proglacial lakes have also formed in recent decades at the end of glaciers on the eastern side of New Zealand's Southern Alps . The most accessible, Lake Tasman , hosts boat trips for tourists. On

210-417: A long moraine bank marking the ice margin. Several processes may combine to form and rework a single moraine, and most moraines record a continuum of processes. Reworking of moraines may lead to the formation of placer deposits of gold as is the case of southernmost Chile . Moraines can be classified either by origin, location with respect to a glacier or former glacier, or by shape. The first approach

245-404: A smaller scale, a mountain glacier may excavate a depression forming a cirque , which may contain a mountain lake, called a tarn , upon the melting of the glacial ice. The movement of a glacier may flow down a valley to a confluence where the other branch carries an unfrozen river. The glacier blocks the river, which backs up into a proglacial lake, which eventually overflows or undermines

280-428: A terminal moraine. They form perpendicular to the lateral moraines that they reside between and are composed of unconsolidated debris deposited by the glacier. They are created during temporary halts in a glacier's retreat. In permafrost areas an advancing glacier may push up thick layers of frozen sediments at its front. An arctic push moraine will then be formed. A medial moraine is a ridge of moraine that runs down

315-569: Is 26.5 cubic metres per second (940 cu ft/s). Record maximum flow was 49.2 cubic metres per second (1,740 cu ft/s) in April 2019, while record minimum flow was 0.711 cubic metres per second (25.1 cu ft/s) in July 1991. Its discharge is affected by the Tea Lake Dam, about 35 kilometres (22 mi) upstream. The Oxtongue River subwatershed , dominated by mixed forest ,

350-517: Is about 35 kilometres (22 mi) east of Huntsville, Ontario , protecting a 6.7 kilometres (4.2 mi) long section of the Oxtongue River from the west boundary of Algonquin Provincial Park to Highway 60. The park includes two notable waterfalls: The area has been recognized for its recreational value since the 1950s. In 1953 and 1959, the Crown land surrounding Ragged Falls was made into

385-472: Is an operating park, meaning that permits are needed for day use. Amenities include parking lot, trails, and washroom. Permitted activities are boating, canoeing, hiking, snowshoeing, hunting, and fishing. Proglacial lake In geology, a proglacial lake is a lake formed either by the damming action of a moraine during the retreat of a melting glacier , a glacial ice dam, or by meltwater trapped against an ice sheet due to isostatic depression of

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420-402: Is controlled by four dams, at Burnt Island, Joe Lake, Tea Lake, and Ragged Lake. Its basin is almost entirely undeveloped, consisting of 28% Crown land and 69% protected in various provincial parks and conservation areas. The river valley has been designated as a Muskoka Heritage Area. Today, the Oxtongue River is used for recreational canoeing . The Oxtongue River-Ragged Falls Provincial Park

455-450: Is home to moose, bear, and other mammal species. The coniferous forest in the Oxtongue River valley is inhabited by various bird species, such as black-backed woodpecker , winter wren , northern saw-whet owl , boreal chickadee , spruce grouse , and various warbler species (including northern parula ). Historically, it was a canoe route for indigenous people . In 1837, surveyor and cartographer David Thompson traveled across

490-450: Is suitable for moraines associated with contemporary glaciers—but more difficult to apply to old moraines , which are defined by their particular morphology, since their origin is debated. Some moraine types are known only from ancient glaciers, while medial moraines of valley glaciers are poorly preserved and difficult to distinguish after the retreat or melting of the glacier. Lateral moraines are parallel ridges of debris deposited along

525-608: The Cordilleran Ice Sheet crept southward into the Idaho Panhandle , forming a large ice dam that blocked the mouth of the Clark Fork River , creating a massive lake 2,000 feet (600 m) deep and containing more than 500 cubic miles (2,000 km ) of water. Finally this Glacial Lake Missoula burst through the ice dam and exploded downstream, flowing at a rate 10 times the combined flow of all

560-821: The Lake of Bays and up the Oxtongue River to reach Canoe Lake, later traveling down the Madawaska River . The Canadian painter Tom Thomson and the Group of Seven painted landscapes along the river. In the late 19th century, the Gilmour Lumber Company used the river for log driving of timber from the Canoe Lake area to their mill in Trenton via the Muskoka and Trent River systems. The river

595-707: The Perito Moreno Glacier , located in Patagonia . Roughly every four years the glacier forms an ice dam against the rocky coast, causing the waters of the Lago Argentino to rise. When the water pressure is too high, then the giant bridge collapses in what has become a major tourist attraction. This sequence occurred last on 4 March 2012, the previous having taken place four years before, in July 2008. About 13,000 years ago in North America,

630-461: The bridge of Highway 35 , there is Marsh's Falls, protected in the 69 ha (170 acres) Marsh's Falls Nature Reserve. From there, the lower Oxtongue River meanders for 4.5 km (2.8 mi) to its mouth at Dwight Bay of Lake of Bays. Over the period 1981 to 2022, the Oxtongue River has a mean flow of 10.9 cubic metres per second (380 cu ft/s). Mean minimal flow is 2.84 cubic metres per second (100 cu ft/s) and mean maximum flow

665-603: The center of a valley floor. It forms when two glaciers meet and the debris on the edges of the adjacent valley sides join and are carried on top of the enlarged glacier. As the glacier melts or retreats, the debris is deposited and a ridge down the middle of the valley floor is created. The Kaskawulsh Glacier in the Kluane National Park , Yukon , has a ridge of medial moraine 1 km wide. Supraglacial moraines are created by debris accumulated on top of glacial ice. This debris can accumulate due to ice flow toward

700-433: The crust around the ice. At the end of the last ice age about 10,000 years ago, large proglacial lakes were a widespread feature in the northern hemisphere. The receding glaciers of the tropical Andes have formed a number of proglacial lakes, especially in the Cordillera Blanca of Peru, where 70% of all tropical glaciers are. Several such lakes have formed rapidly during the 20th century. These lakes may burst, creating

735-511: The glacier has melted. Moraines may form through a number of processes, depending on the characteristics of sediment, the dynamics on the ice, and the location on the glacier in which the moraine is formed. Moraine forming processes may be loosely divided into passive and active . Passive processes involve the placing of chaotic supraglacial sediments onto the landscape with limited reworking, typically forming hummocky moraines. These moraines are composed of supraglacial sediments from

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770-428: The glacier margin (up to 80 degrees) than further away (where slopes are typically 29 to 36 degrees. Ground moraines are till-covered areas with irregular topography and no ridges, often forming gently rolling hills or plains, with relief of less than 10 meters (33 ft). Ground moraine is accumulated at the base of the ice as lodgment till with a thin and discontinuous upper layer of supraglacial till deposited as

805-544: The glacier retreats. It typically is found in the areas between end moraines. Rogen moraines or ribbed moraines are a type of basal moraines that form a series of ribs perpendicular to the ice flow in an ice sheet . The depressions between the ribs are sometimes filled with water, making the Rogen moraines look like tigerstripes on aerial photographs . Rogen moraines are named after Lake Rogen in Härjedalen , Sweden ,

840-578: The glacier. Other types of moraine include ground moraines ( till -covered areas forming sheets on flat or irregular topography ) and medial moraines (moraines formed where two glaciers meet). The word moraine is borrowed from French moraine [mɔ.ʁɛn] , which in turn is derived from the Savoyard Italian morena ('mound of earth'). Morena in this case was derived from Provençal morre ('snout'), itself from Vulgar Latin * murrum ('rounded object'). The term

875-531: The ice dam, suddenly releasing the impounded water in a glacial lake outburst flood also known by its Icelandic name a jökulhlaup . Some of the largest glacial floods in North American history were from Lake Agassiz . In modern times, the Hubbard Glacier regularly blocks the mouth of Russell Fjord at 60° north on the coast of Alaska. A similar event takes place after irregular periods in

910-415: The ice surface. Active processes form or rework moraine sediment directly by the movement of ice, known as glaciotectonism. These form push moraines and thrust-block moraines, which are often composed of till and reworked proglacial sediment. Moraine may also form by the accumulation of sand and gravel deposits from glacial streams emanating from the ice margin. These fan deposits may coalesce to form

945-503: The landform's type locality. Closely related to Rogen moraines, de Geer moraines are till ridges up to 5m high and 10–50m wide running perpendicular to the ice flow. They occur in large groups in low-lying areas. Named for Gerard De Geer , who first described them in 1889, these moraines may have developed from crevasses underneath the ice sheet. The Kvarken has a very high density of de Geer moraines. End moraines, or terminal moraines , are ridges of unconsolidated debris deposited at

980-411: The moraine. There are two types of end moraines: terminal and recessional. Terminal moraines mark the maximum advance of the glacier. Recessional moraines are small ridges left as a glacier pauses during its retreat. After a glacier retreats, the end moraine may be destroyed by postglacial erosion. Recessional moraines are often observed as a series of transverse ridges running across a valley behind

1015-563: The rapid and catastrophic release of dammed water resulting in the formation of gorges and other structures downstream from the former lake. Good examples of these structures can be found in the Channeled Scablands of eastern Washington, an area heavily eroded by the Missoula Floods . The following table is a partial list of rivers that had glacial ice dams. The retreating glaciers of the last ice age, both depressed

1050-562: The rivers of the world. Because such ice dams can re-form, these Missoula Floods happened at least 59 times, carving Dry Falls below Grand Coulee . In some cases, such lakes gradually evaporated during the warming period after the Quaternary ice age. In other cases, such as Glacial Lake Missoula and Glacial Lake Wisconsin in the United States, the sudden rupturing of the supporting dam caused glacial lake outburst floods ,

1085-454: The sides of a glacier. The unconsolidated debris can be deposited on top of the glacier by frost shattering of the valley walls or from tributary streams flowing into the valley, or may be subglacial debris carried to the surface of the glacier, melted out, and transported to the glacier margin. Lateral moraines can rise up to 140 meters (460 ft) over the valley floor, can be up to 3 kilometers (1.9 mi) long, and are steeper close to

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1120-427: The snout or end of the glacier. They usually reflect the shape of the glacier's terminus . Glaciers act much like a conveyor belt, carrying debris from the top of the glacier to the bottom where it deposits it in end moraines. End moraine size and shape are determined by whether the glacier is advancing, receding or at equilibrium. The longer the terminus of the glacier stays in one place, the more debris accumulate in

1155-419: The surface in the ablation zone , melting of surface ice or from debris that falls onto the glacier from valley sidewalls. Washboard moraines , also known as minor or corrugated moraines , are low-amplitude geomorphic features caused by glaciers. They consist of low-relief ridges, 1 to 2 meters (3 ft 3 in to 6 ft 7 in) in height and around 100 meters (330 ft) apart, accumulated at

1190-730: The terrain with their mass and provided a source of meltwater that was confined against the ice mass. Lake Algonquin is an example of a proglacial lake that existed in east-central North America at the time of the last ice age . Parts of the former lake are now Lake Huron , Georgian Bay , Lake Superior , Lake Michigan and inland portions of northern Michigan. Examples in Great Britain include Lake Lapworth , Lake Harrison and Lake Pickering . Ironbridge Gorge in Shropshire and Hubbard's Hills in Lincolnshire are examples of

1225-467: Was introduced into geology by Horace Bénédict de Saussure in 1779. Moraines are landforms composed of glacial till deposited primarily by glacial ice. Glacial till, in turn, is unstratified and unsorted debris ranging in size from silt -sized glacial flour to large boulders. The individual rock fragments are typically sub-angular to rounded in shape. Moraines may be found on the glacier's surface or deposited as piles or sheets of debris where

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