Northwest Ohio is famous for its history of The Great Black Swamp. Although the area is primarily flat there are a few sandy ridges in the area.
This Earth cache is to educate you on how they were formed and to bring you to one of the highest in the Defiance county area. As you approach this area it will look really unusual because of its height.
The ridges in this area vary in the material they are made of. Some are a red soil with a gravel/sand mixture while others are a clay/lome mix with gravel and then there are some that have only fine beach like sand.
Great Black Swamp
The Great Black Swamp, or simply Black Swamp, was a glacially caused wetland in northwest Ohio, United States, extending into extreme northeastern Indiana, that existed from the end of the Wisconsin glaciation until the late 19th century.
It comprised extensive swamps and marshes, with some higher, drier ground interspersed, and occupied what was formerly the southwestern part of Glacial Lake Maumee, a holocene precursor to Lake Erie. It was gradually drained and settled in the second half of the 19th century and is now highly productive farm land.
Its historical boundaries lie primarily within the watersheds of the Maumee, Auglaize, and Portage rivers in northwest Ohio. The boundary was determined primarily by ancient sandy beach ridges formed on the shores of Lakes Maumee and Whittlesey, after glacial retreat several thousand years ago. It stretched roughly from New Haven, Indiana in the west, to Toledo and Sandusky Ohio on the east. Additional watersheds partly or wholly within its former boundary include the Sandusky, Ottawa, Tiffin, and Blanchard rivers
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The area was not continuous swamp, but rather characterized by a variety of vegetation types. In the lowest, flattest areas, prone to permanent inundation, deciduous swamp forests predominated, characterized especially by species of ash, elm, cottonwood and sycamore. In slightly higher areas with some topographic relief and better drainage, beech, maples, basswood, tuliptree and other more mesic species were dominant.
On elevated beach ridges and moraines with good to excessive drainage, more xeric species, especially of oak and hickory, were dominant. Unlike other swampy areas of the Great Lakes, such as northern Minnesota, there were no conifers. There were also non-forested wetlands, particularly marsh and wet prairies, with marshes being particularly extensive along the Lake Erie shoreline between Toledo and Sandusky. Some of these exist today in modified form in state and federal wildlife refuges, such as Ottawa National Wildlife Refuge.
Glacier Left Black Swamp
The history of Northwest Ohio has been shaped by geology. How and when it was settled and by whom were the direct results of events occurring thousands of years ago. In that period, beginning a million years ago, great sheets of ice began to move southward into the United States.
These glaciers gouged soils and rocks, carried with them great quantities of clay, mud, sand, gravel and boulders frozen into the ice. As they receded, they buried the low hills of western Ohio under thick layers of glacial till, a mixture of sand, clay, gravel and boulders. The melting glaciers formed lakes which left several different shorelines recognizable as ridges.
The last glacier, passing through the region 10,000 years ago, deposited its glacial till in layers one to 90 feet thick. As the glacier melted, a broad river valley filled up with water, becoming Lake Erie. The outlet for glacial Lake Erie's water was frozen, and consequently the waters overflowed, forming a large backwater lake.
The waters, having to find another outlet, cut new streams to the Mississippi River drainage system; the Maumee River flowed over the water divide to join the Wabash River in Indiana. Into glacial Lake Erie came the soil eroded by the cutting actions of many streams. The silts and clays deposited a heavy layer of material over the impermeable glacial till. Deposited directly below was the sand; in some areas of Lucas county, sand is 15 to 30 feet thick
When the glacier left Northwest Ohio, its legacy was the Black Swamp, 30 miles wide and extending southwestward from Lake Erie to New Haven, Ind. Elm and ash trees quickly sprouted in this moist soil, eventually forming a dense forest. Standing water predominated. Even in the dry areas, water oozed out of the ground when stepped upon. Interspersed among the trees were wet prairies characterized by rushes, grasses and the high- bush cranberry
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Ohio's Five Physiographic Regions
LAKE PLAINS
• Once the bottom of a much larger ancient lake known as Lake Maumee, this region is an extremely flat plain
• A narrow strip of land along the Lake Erie coast in northeastern Ohio, it broadens significantly west of Cleveland
• As water levels rose and fell, sandy beach ridges and dunes formed along the shore
• The northwestern area of the region was called the Great Black Swamp - marked by rich, black soils and poor drainage
GLACIATED APPALACHIAN PLATEAU
• Carved by glaciers and ancient streams, this region is less hilly and lacks the rugged quality of the unglaciated landscape
• Following glaciation, many streams reversed their flow, cutting new paths throughout the region
• Evidence of the region's glacial past includes bogs, kettle lakes, and a landscape marked by small hills of sand and gravel called "kames"
• Today, the area is marked by smaller tracts of forests, ranging from a few acres to hundreds of acres
TILL PLAINS
• This fertile region located south of the Lake Plains is not as flat and is characterized by gently rolling hills
• Most hills are a series of moraines, which are glacier-created mounds of rock and soil that are up to 100 feet high and 6 miles wide
• A hilly belt of bedrock in Bellefontaine rises 1,549 feet above sea level - the highest point in the state, called Campbell's Hill
• Glaciers created terraces along valley sides and new drainage patterns including today's Ohio River
UNGLACIATED APPALACHIAN PLATEAU
• Untouched by glaciers, this southeastern Ohio region features deep valleys, high hills and winding streams
• Sandstone, resistant to erosion and common in the region, supports a variety of cliffs, gorges, natural bridges and waterfalls
• Although the region has thousands of forested acres, the topography is rough and much of the soil is infertile
• A long belt of high hills on the eastern edge, running from Monroe to Columbiana County, divides eastward and westward flowing streams
BLUEGRASS
• A small, triangular region that reaches up into southern Ohio's Adams County from Kentucky
• Flat-topped hills and uplands rimmed by cliffs define the area
• Limestone, dolomite and shale bedrock are characteristic of the region and its landscape moves from gentle slopes to steep slopes, depending on erosion
• Some uplands are marked by sink holes or depressions that formed in rocks composed mainly of chalk
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