Niagara Escarpment in the context of "Grimsby, Ontario"

Dolomite (also known as dolomite rock, dolostone or dolomitic rock) is a sedimentary carbonate rock that contains a high percentage of the mineral dolomite, CaMg(CO₃)₂. It occurs widely, often in association with limestone and evaporites, though it is less abundant than limestone and rare in Cenozoic rock beds (beds less than about 66 million years in age). One of the first geologists to distinguish dolomite from limestone was Déodat Gratet de Dolomieu, a French mineralogist and geologist after whom it is named. He recognized and described the distinct characteristics of dolomite in the late 18th century, differentiating it from limestone.

Most dolomite was formed as a magnesium replacement of limestone or of lime mud before lithification. The geological process of conversion of calcite to dolomite is known as dolomitization and any intermediate product is known as dolomitic limestone. The "dolomite problem" refers to the vast worldwide depositions of dolomite in the past geologic record in contrast to the limited amounts of dolomite formed in modern times. Sulfate-reducing bacteria living in anoxic conditions can precipitate dolomite suggesting that some past dolomite deposits might be due to microbial activity. Recent laboratory research focused on the crystal growth of dolomite at the microscopic scale has revealed that multiple cycles of precipitation/dissolution can promote the growth of dolomite crystals.

The Humber River (Ojibwe: Gabekanaang-ziibi, lit. 'river at the end of the trail') is a river in Southern Ontario, Canada. It is in the Great Lakes Basin, is a tributary of Lake Ontario and is one of two major rivers on either side of the city of Toronto, the other being the Don River to the east. It was designated a Canadian Heritage River on September 24, 1999.

The Humber collects from about 750 creeks and tributaries in a fan-shaped area north of Toronto that encompasses portions of Dufferin County, the Regional Municipality of Peel, Simcoe County, and the Regional Municipality of York. The main branch runs for about 100 kilometres (60 mi) from the Niagara Escarpment in the northwest, while another major branch, known as the East Humber River, starts at Lake St. George in the Oak Ridges Moraine near Aurora to the northeast. They join north of Toronto and then flow in a generally southeasterly direction into Lake Ontario at what was once the far western portions of the city. The river mouth is flanked by Sir Casimir Gzowski Park and Humber Bay Park East.

Green Bay is an arm of Lake Michigan, located along the south coast of Michigan's Upper Peninsula and the east coast of Wisconsin. It is separated from the rest of the lake by the Door Peninsula in Wisconsin, the Garden Peninsula in Michigan, and the chain of islands between them, all formed by the Niagara Escarpment. Green Bay is some 120 miles (193 km) long, with a width ranging from about 10 to 20 miles (16 to 32 km); it is 1,626 square miles (4,210 km) in area.

At the southern end of the bay is the city of Green Bay, Wisconsin, where the Fox River enters the bay. The Leo Frigo Memorial Bridge (formerly known as the Tower Drive bridge) spans the point where the bay begins and the Fox River ends, as the river flows south to north into the bay. Around mid-bay are Sturgeon Bay and the Peshtigo River. The Sturgeon Bay serves the city named after the bay as a shortcut for large ships to use to bypass the Door Peninsula, while the Peshtigo River serves Peshtigo and Crivitz. Locally, the bay is called the Bay of Green Bay to distinguish it from the city.

The Niagara River (/naɪˈæɡərə, -ɡrə/ ny-AGG-ər-ə, -⁠grə) flows north from Lake Erie to Lake Ontario, forming part of the border between Ontario, Canada, to the west, and New York, United States, to the east. The origin of the river's name is debated. Iroquoian scholar Bruce Trigger suggests it is derived from a branch of the local Neutral Confederacy, referred to as the Niagagarega people on several late-17th-century French maps. George R. Stewart posits that it comes from an Iroquois town named Ongniaahra, meaning "point of land cut in two."

The river, occasionally described as a strait, is approximately 58 kilometres (36 mi) long and includes the Niagara Falls. Over the past 12,000 years, the falls have moved roughly 11 kilometres (6.8 mi) upstream from the leading edge of the Niagara Escarpment, creating a gorge below the falls. Today, the diversion of the river for electricity generation has significantly slowed the rate of erosion. The total elevation drop along the river is 99 metres (325 ft). The Niagara Gorge, downstream from the falls, includes the Niagara Whirlpool and additional rapids.

The Welland Canal is a ship canal in Ontario, Canada, and part of the St. Lawrence Seaway and Great Lakes Waterway. The canal traverses the Niagara Peninsula between Port Weller on Lake Ontario and Port Colborne on Lake Erie, and was built because the Niagara River—the only natural waterway connecting the lakes—was unnavigable due to Niagara Falls. The Welland Canal enables ships to ascend and descend the Niagara Escarpment, and has followed four different routes since it opened.

The Welland Canal passes about 3,000 ships which transport about 40 million tonnes (88 billion pounds) of cargo a year. It was a major factor in the growth of the city of Toronto, Ontario. The original canal and its successors allowed goods from Great Lakes ports such as Cleveland, Detroit, Milwaukee, and Chicago, as well as other heavily industrialized areas of the United States and Ontario, to be shipped to the Port of Montreal or to Quebec City, where they were usually reloaded onto ocean-going vessels for international shipping.

The Great Lakes-St. Lawrence Lowlands, or simply St. Lawrence Lowlands, is a physiographic region of Eastern Canada that comprises a section of southern Ontario bounded on the north by the Canadian Shield and by three of the Great Lakes — Lake Huron, Lake Erie and Lake Ontario — and extends along the St. Lawrence River to the Strait of Belle Isle and the Atlantic Ocean. The lowlands comprise three sub-regions that were created by intrusions from adjacent physiographic regions — the West Lowland, Central Lowland and East Lowland. The West Lowland includes the Niagara Escarpment, extending from the Niagara River to the Bruce Peninsula and Manitoulin Island. The Central Lowland stretches between the Ottawa River and the St. Lawrence River. The East Lowland includes Anticosti Island, Îles de Mingan, and extends to the Strait of Belle Isle.

The St. Lawrence Lowlands is one of the most densely populated, prosperous and productive regions in Canada. Major urban areas include Toronto, Montreal, Ottawa-Gatineau and Quebec City.

The Oak Ridges Moraine is an ecologically important geological landform in the Mixedwood Plains of south-central Ontario, Canada. The moraine covers a geographic area of 1,900 square kilometres (730 sq mi) between Caledon and Rice Lake, near Peterborough. One of the most significant landforms in southern Ontario, the moraine gets its name from the rolling hills and river valleys extending 160 km (99 mi) east from the Niagara Escarpment to Rice Lake, formed 12,000 years ago by advancing and retreating glaciers (see geological origins, below) during the last glaciation period. Below the approximately 200 metre thick glacial derived sediments of the moraine lies thick bedrock successions of Precambrian rocks and up to 200 metres of Ordovician aged rock (see geology below), capped by a regional unconformity of erosion and non-deposition to the Quaternary period. Rivers and lakes scatter the landscape and are important for creating habitat for the rich diversity of species of animals, trees and shrubbery (see ecology). These are also the supply of fresh water to aquifers in the moraine through complex subterranean connections (see hydrology). Construction development nearby, and with expansion of communities around the moraine in need of potable water, it is a contested site in Ontario, since it stands in the path of major urban development (see political action). Conservation of the moraine is thus an important step for keeping aquifers in a safe drinkable condition while also protecting the natural ecosystems surrounding and within the moraine (see conservation). This region has been subject to multiple decades of scientific research to study the origins of formation, and how early communities used the land. A larger focus currently is how to source potable water without removing the aquifer entirely (see research section).

The Door Peninsula is a peninsula in eastern Wisconsin, separating the southern part of the Green Bay from Lake Michigan. The peninsula includes northern Kewaunee County, northeastern Brown County, and the mainland portion of Door County. It is on the western side of the Niagara Escarpment. Well known for its cherry and apple orchards, the Door Peninsula is a popular tourism destination. With the 1881 completion of the Sturgeon Bay Ship Canal, the northern half of the peninsula became an island.

Limestone outcroppings of the Niagara Escarpment are visible on both shores of the peninsula, but are larger and more prominent on the Green Bay side as seen at the Bayshore Blufflands. Progressions of dunes have created much of the rest of the shoreline, especially on the east side. Flora along the shore demonstrate plant succession during periods of low lake levels. The middle of the peninsula is mostly flat. Beyond the peninsula's northern tip is a series of islands, the largest of which is Washington Island. The partially submerged ridge extends farther north, becoming the Garden Peninsula in Michigan's Upper Peninsula.