Misplaced Pages

#395604

22-471: The Maumee Torrent , also known as the Maumee Megaflood , was a catastrophic draining of Lake Maumee , the ancestor of present-day Lake Erie , that occurred approximately 14,000 to 17,000 years ago during the late Wisconsin glaciation . It happened when the waters of Lake Maumee, possibly in response to an advance of the ice front at the eastern end of the lake, overtopped a " sag " or low spot in

44-896: A beach ridge is affected by wave size and energy. A fall in water level (or an uplift of land) can isolate a beach ridge from the body of water that created it. Isolated beach ridges may be found along dry lakes in the western United States and inland of the Great Lakes of North America , where they formed at the end of the last ice age when lake levels were much higher due to glacial melting and obstructed outflow caused by glacial ice. Some isolated beach ridges are found in parts of Scandinavia , where glacial melting relieved pressure on land masses and resulted in subsequent crustal lifting or post-glacial rebound . A rise in water level can submerge beach ridges created at an earlier stage, causing them to erode and become less distinct. Beach ridges can become routes for roads and trails, like in

66-614: A previously existing low-lying area that was the valley of an eastward-flowing river known as the Erigan River that probably emptied into the Atlantic Ocean following the route of today's Saint Lawrence River . Some geologists think that the Erigan could have been a downstream segment of the preglacial Teays River system. The glaciers destroyed or disturbed most of the preglacial drainage patterns and enlarged and deepened

88-541: A short time. The highest beach is 785 to 790 feet (239 to 241 m), near the Fort Wayne outlet, In Michigan it is about 800 feet (240 m)with areas in Lapeer county its nearly 850 feet (260 m). The Imlay outlet is 805 to 810 feet (245 to 247 m) above sea level or 50 feet (15 m) above the bed of the Fort Wayne outlet. This outlet flowed to the west, into a developing Lake Saginaw and thence into

110-480: Is a wave -swept or wave-deposited ridge running parallel to a shoreline. It is commonly composed of sand as well as sediment worked from underlying beach material. The movement of sediment by wave action is called littoral transport . Movement of material parallel to the shoreline is called longshore transport . Movement perpendicular to the shore is called on-offshore transport . A beach ridge may be capped by, or associated with, sand dunes . The height of

132-596: The Fort Wayne Moraine . The flood removed all earlier sediment and deepened the valley bottom by 20 feet (6.1 m). Lake Maumee had reached 800 feet (240 m) above sea level when the lake poured through a sag in the Fort Wayne Moraine into the ancestral Little River and then the Wabash River . There is some evidence that the final rise in lake level that caused it to overtop the moraine

154-1118: The Grand River in Michigan and into Glacial Lake Chicago , an ancestor of present-day Lake Michigan . Another advance of the ice blocked that outlet, raising the lake level to about 780 feet (240 m) ASL, the stage known as the Middle Maumee. A new outlet, the Imlay Outlet, formed that connected with an unobstructed segment of the Grand River farther west. There is enough uncertainty about this sequence that some authorities think that Middle Maumee might have preceded Lowest Maumee. Fluctuations in water level continued through more stages (Arkona, 695 feet (212 m); Whittlesey, 738 feet (225 m) ASL; Warren and Wayne, 660–685 feet (201–209 m) ASL; and Lundy, 590–640 feet (180–200 m) ASL. This see-saw pattern continued until an eastern outlet opened at Niagara , establishing

176-521: The Little River , is the largest topographical feature in Allen County, Indiana . As much as 30 feet of fine sand, silt and organic sediments were deposited in the channel before drainage reversed and was captured by the present-day Maumee River . U.S. Route 24 between Fort Wayne and Huntington follows the channel. Approximately 14,000 years before present, Lake Maumee overtopped

198-606: The Erigan basin. Lake Maumee is the first of a series of glacial lakes which occupied the Erie basin. It was preceded by a few small, disconnected lakes which lay between the ice margin and the southern divide of Erie basin. The name Lake Maumee was first applied in 1888 by G. R. Dryer of the Indiana Geological Survey in an official report on the geology of Allen County, Indiana. As the Erie Lobe retreated to

220-478: The Fort Wayne Moraine , which was a deposit of glacial debris that acted as a natural dam at the site of present-day Fort Wayne, Indiana . This unleashed a massive flow of water that scoured a one- to two-mile-wide outlet running southwest to the Wabash River known as the "Wabash-Erie Channel", which probably followed the course of earlier, less massive drainage. The channel, now a small stream called

242-491: The Grand River Channel (proto Maple and Lower Grand rivers). The highest beach is very irregular. The first or highest beach exposure to wave action that the other beaches do not reflect. The second beach is more regular, and on the whole somewhat stronger than the highest. There is a third beach, which is generally weak and in places difficult to trace. The third beach connects with well-defined deltas which

SECTION 10

#1732772080396

264-434: The beach is at 801 and 798 feet (244 and 243 m). The strong beach is generally above 800 feet (240 m)and at a few points rises to 810 and 812 feet (247 and 247 m). On the south side of Lake Maumee the highest beach 775 and 785 feet (236 and 239 m) from Fort Wayne to Cleveland . The maps show it to be 810 and 812 feet (247 and 247 m) from Delphos to Findlay . Beach ridge A beach ridge

286-567: The bed of Glacial Lake Maumee. Geologists call the former lake bottom the Maumee Lacustrine Plain . The altitude of the highest Maumee beach is 775 to 780 feet (236 to 238 m) at the head of the outlet in the vicinity of Fort Wayne and New Haven, Ind. To the northeast, 50 to 75 miles (80 to 121 km), along the Ohio and Michigan state line, it is 20 to 25 feet (6.1 to 7.6 m) higher. In West Unity and Fayette, Ohio ,

308-582: The case of the west coast in the Netherlands , where isolated beach ridges were formed early on in the Holocene , during the Atlanticum , behind newly formed dunes . The old and the new beach ridges are the only dry routes amidst wet peatland . Numerous settlements emerged here, some of them developed in large populous centers, like The Hague , Haarlem and Alkmaar . This geology article

330-513: The drainage pattern of modern Lake Erie (569 feet (173 m) ASL). This involved the reversal of drainage in what is now northeastern Indiana and northwestern Ohio as the Maumee River outlet developed by capturing streams that formerly drained into the Wabash. The Great Black Swamp that once occupied much of the land between Sandusky, Ohio , and New Haven, Indiana , was a remnant of

352-695: The higher levels do not have. The most notable are at the Raisin and the Huron rivers. The third beach is 20 feet (6.1 m) below the Imlay outlet. The outlet at that time may be across the "Thumb" in a lower passage a few miles north. The readvance of the ice sheet may have closed this outlet with a moraine closely bordering the Imlay outlet. The lake beaches, because of their sandy or gravelly constitution, form better lines for highways than neighboring clayey tracts. Thus, early roads followed these natural routes along

374-502: The lakes. The move to building roads on north and south and east and west lines has led to the abandonment of all or part of these ‘beach’ roads. Two later stages of Lake Maumee, (called the "Lowest" and the "Middle," in that order) had lower water levels because the retreating ice exposed an outlet lower than the Wabash-Erie Channel. The Lowest Maumee (elevation: about 760 ft (232 m) ASL) drained westward through

396-644: The length of the Wabash River. The limestone bedrock under the Little River Valley near Huntington created a sill, limiting the depth to which the Torrent and the future river could erode. The well-developed beach ridges in Ohio and eastern Allen County show a series of lower lake levels. Lake Maumee As the ice sheet retreated at the end of the last ice age , it left meltwater in

418-504: The northeast, it left large debris deposits called moraines running at right angles to its line of retreat. One of these, called the Fort Wayne Moraine , was left at the site of present-day Fort Wayne, Indiana , where it acted as a dam that held back the waters of the lake. When the water was at its highest point, about 800 feet ASL (244 m ASL, but as low as 210-224 masl in stable Maumee delta zones due to differential isostatic rebound of end moraines), it left beach ridges that later became

440-562: The routes of trails and highways. During this stage, the waters of the lake, possibly in response to an advance of the ice front at the lake's eastern end, overtopped a "sag" in the Fort Wayne Moraine. This caused a catastrophic drainage of the lake known as the Maumee Torrent that scoured a one- to two-mile-wide outlet running southwest to the Wabash River known as the Wabash-Erie Channel . The lake's initial outlet

462-473: Was at present day Fort Wayne, Indiana , the lowest place on the border of the basin. Its altitude seems to have been at first about 785 feet (239 m), or 212 feet (65 m) above the current level of Lake Erie, but during its life as an outlet, reduced to 760 feet (230 m). At its highest point, the lake used this single outlet. Later, after further ice melt a northerly outlet was reached near present-day Imlay City, Michigan , and lake had two outlets for

SECTION 20

#1732772080396

484-540: Was caused by a minor re-advance of the glacier further east in the basin. The soft till of the moraine was quickly eroded by the volume of water in the lake, releasing a massive volume of water. A second outlet opened at Six-Mile Creek into the St. Marys River and into the Little River Valley. The earlier sediments were removed in bulk, leaving only the Sand Point and a few gravel terraces on the valley walls. The flood scoured

#395604