Niagara Escarpment

The Niagara Escarpment is a long escarpment, or cuesta, in the United States and Canada that runs predominantly east/west from New York State, through Ontario, Michigan, Wisconsin and Illinois. It is composed of the Lockport geological formation of Silurian age, and is similar to the Onondaga geological formation, which runs parallel to it and just to the south, through western New York and southern Ontario. The escarpment is most famous as the cliff over which the Niagara River plunges at Niagara Falls, for which it is named.

The Niagara Escarpment is the most prominent of several escarpments formed in the bedrock of the Great Lakes basin. From its easternmost point near Watertown, New York, the escarpment shapes in part the individual basins and landforms of Lakes Ontario, Huron and Michigan. In Rochester, New York, there are three waterfalls over the escarpment where the Genesee River flows through the city. The escarpment thence runs westward to the Niagara River forming a deep gorge north of Niagara Falls, which itself cascades over the escarpment. In southern Ontario it spans the Niagara Peninsula, closely following the Lake Ontario shore through the cities of St. Catharines, Hamilton and Dundas, where it takes a sharp turn north in the town of Milton toward Georgian Bay. It then follows the Georgian Bay shore northwestwards to form the spine of the Bruce Peninsula and Manitoulin Island, as well as several smaller islands located in northern Lake Huron where it turns westwards into the Upper Peninsula of northern Michigan, south of Sault Ste. Marie. It then extends southwards into Wisconsin following the Door Peninsula through the Bayshore Blufflands and then more inland from the western coast of Lake Michigan and Milwaukee, ending northwest of Chicago near the Wisconsin-Illinois border.

Escarpment

An escarpment is a steep slope or long cliff that occurs from faulting, tilting or warping and resulting erosion and separates two relatively level areas of differing elevations. Usually escarpment is used interchangeably with scarp (from the Italian scarpa, shoe). But some sources differentiate the two terms, where escarpment refers to the margin between two landforms, while scarp is synonymous with a cliff or steep slope. The surface of the steep slope is called a scarp face.

Formation and description

Scarps are generally formed by one of two processes: either by differential erosion of sedimentary rocks, or by vertical movement of the Earth's crust along a geologic fault. Most commonly, an escarpment is a transition from one series of sedimentary rocks to another series of a different age and composition.

Escarpments are also frequently formed by faults. When a fault displaces the ground surface so that one side is higher than the other, a fault scarp is created. This can occur in dip-slip faults, or when a strike-slip fault brings a piece of high ground adjacent to an area of lower ground.

Door County, Wisconsin

Door County is a county in the U.S. state of Wisconsin. As of the 2010 census, the population was 27,785. Its county seat is Sturgeon Bay.

The county was created in 1851 and organized in 1861. It is named after the strait between the Door Peninsula and Washington Island. The dangerous passage, which is now scattered with shipwrecks, was known to early French explorers and local Native Americans. Because of the natural hazards of the strait, where the waters of Green Bay meet the open body of Lake Michigan, they gave it the French appellation Porte des Morts, which in English means "Death's Door."

Door County is a popular vacation and tourist destination, especially for residents of Wisconsin and Illinois.

History

The Door County peninsula has been inhabited for about 11,000 years. Artifacts from an ancient village site at Nicolet Bay Beach have been dated to about 400 BC. This site was occupied by various cultures until about 1300 AD.

The 18th and 19th centuries saw the immigration and settlement of pioneers, mariners, fishermen and farmers, with the first white settler being Increase Claflin. Economic sustenance came from lumbering and tourism.