The Canadian Shield—also called the Laurentian Plateau, or Bouclier Canadien (French)—is a massive geological shield covered by a thin layer of soil that forms the nucleus of the North American or Laurentia craton. It is an area mainly covered by igneous rock which relates to its long volcanic history.
The Genesee River flows northward from its source in northern Pennsylvania to enter Lake Ontario at Rochester, New York. The present river valley has been modified extensively from preglacial river valleys. A lobe of the last glacier (Wisconsonian) pushed southward almost to the Pennsylvania line, dramatically reshaping the drainage patterns of central and western New York.
Glacial Lake Tonawanda was a prehistoric lake that existed approximately 10,000 years ago at the end of the last ice age, in Western New York, United States. The lake existed on the southern (upper) side of the Niagara Escarpment east of the present course of the Niagara River between Early Lake Erie to the south and Glacial Lake Iroquois (the ancestor of Lake Ontario) to the north. During the retreat of the glaciers, the water levels of the Great Lakes were higher.
The Onondaga Formation is a group of hard limestones and dolostones of Devonian age that form an important geographic feature in some areas in which it outcrops, in others; especially its Southern Ontario portion, the formation can be less prominent as a local surface feature.
The Laurentide Ice Sheet was a massive sheet of ice that covered hundreds of thousands of square miles, including most of Canada and a large portion of the northern United States, between c. 95,000 and c. 20,000 years before the present day. Its southern margin included the modern sites of New York City and Chicago, and then followed quite precisely the present course of the Missouri River up to the northern slopes of the Cypress Hills, beyond which it merged with the Cordilleran Ice Sheet.
The Acadian orogeny is a middle Paleozoic mountain building event, especially in the northern Appalachians, between New York and Newfoundland. The Acadian orogeny most greatly affected the Northern Appalachian region (New England northeastward into the Gaspé region of Canada). The Acadian orogeny should not be regarded as a single tectonic event, but rather as an orogenic era. It spanned a period of about 50 million years, from 375 to 325 million years ago.
The Taconic orogeny was a great mountain building period that perhaps had the greatest overall effect on the geologic structure of basement rocks within the New York Bight region. The effects of this orogeny are most apparent throughout New England, but the sediments derived from mountainous areas formed in the northeast can be traced throughout the Appalachians and midcontinental North America.
The Queenston Delta is a 300-mile-wide clastic wedge of sediment deposited over what is now eastern North America during the late Ordovician period due to the erosion of mountains created during the Taconic orogeny. The wedge is thickest in a band running from New York State to Quebec.
The Devonian Catskill Formation (Dck) or the Catskill clastic wedge is a unit of mostly terrestrial sedimentary rock found in Pennsylvania and New York. Minor marine layers exist in this thick, up to 10,000 feet, rock unit. It is equivalent to the Hampshire Formation of Maryland, West Virginia, and Virginia. The Catskill is the largest bedrock unit of the Upper Devonian in Northeast Pennsylvania and the Catskill region of New York; the latter of which its name is derived.
Dimension stone is natural stone or rock that has been selected and fabricated (i.e. , trimmed, cut, drilled, ground, or other) to specific sizes or shapes. Color, texture and pattern, and surface finish of the stone are also normal requirements. Another important selection criterion is durability, the time measure of the ability of dimension stone to endure and to maintain its essential and distinctive characteristics of strength, resistance to decay, and appearance.
Pennsylvania Bluestone is a layered sandstone found only in the northeastern tier of Pennsylvania, parts of northern New Jersey and the southern tier of New York. The quarried product has many uses, from cut dimensional stone used in patios, walkways and stair treads to architectural stone used in buildings. It is also used for wallstone, decorative boulders, natural steps and other landscape features.
The Clarendon-Linden fault system is a major series of fault lines in western New York state, in the United States. It extends through Orleans, Genesee, Wyoming, and into Allegany counties and is responsible for much of the seismic activity in the region. The system is named in part for the town of Clarendon, New York.
Glacial Lake Maumee was a proglacial lake that was an ancestor of present-day Lake Erie. It formed about 14,000 years ago. As the Erie Lobe of the Wisconsin Glacier retreated at the end of the last ice age, it left meltwater in a previously-existing depressional 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 (see M.C.
The Manhattan schist is a formation of mica schist rock that underlies much of the island of Manhattan in New York City. It is well suited for the foundations of tall buildings and the two large concentrations of skyscrapers on the island occur where the formation is close to the surface.
The Chazy Reef Formation is a mid-Ordovician limestone deposit that consists of some of the oldest reef systems built by a community of organisms rather than the deposit of a limited range of similar organisms, such as Stromatolite mounds deposited by ancient cyanobacteria. The reef structure was formed largely by cryptostome and trepostome bryozoa, some of the oldest known bryozoans, but corals made an early appearance, and stromatoporoids.
The Palisades Sill is a Triassic, 200 Ma diabase intrusion. It extends through portions of New York and New Jersey. It is most noteworthy for The Palisades, the cliffs that rise steeply above the western bank of the Hudson River. The ideal location and accessibility of the sill, as well as its unique features, have generated much attention from nature enthusiasts and geologists alike.
The Silurian Shawangunk Formation (Ss) is a mapped bedrock unit in eastern Pennsylvania, New Jersey, and New York. It is named for the Shawangunk Ridge for which it is the dominant rock type. The division of the Shawangunk between the Tuscarora Formation and Clinton Group has not been conclusively determined. The shift of nomenclature currently has the divide between Hawk Mountain and Lehigh Gap.
The Silurian Bloomsburg Formation (Sb) is a mapped bedrock unit in Pennsylvania, New Jersey, New York and Maryland. It is named for the Town of Bloomsburg, Pennsylvania for which it was first described. The Bloomsburg marked the first occurrence of red sedimentary rocks in the Appalachian Basin. Early American geologists theorized that these beds correlated with Old Red Sandstone found in Scotland.
The Frontenac Axis is an exposed strip of precambrian rock in Canada and the United States which links the Canadian Shield with the Adirondack mountain range in New York, an extension of the Laurentian mountains of Québec. The axis separates the St. Lawrence Lowlands and the Great Lakes Lowlands. It is an ecoregion of the Mixedwood Plains. It also separates the Canadian Shield and the Lowlands.
The Passaic Formation is a mapped bedrock unit in Pennsylvania, New Jersey, and New York. It was previously known as the Brunswick Formation since it was first described in the vicinity of New Brunswick, New Jersey. It is now named for the Passaic River in New Jersey.
The Newark Basin is a sediment-filled rift basin located mainly in northern New Jersey but also stretching into south-eastern Pennsylvania and southern New York. It is part of the system of Eastern North America Rift Basins.
Stark's Knob is a basaltic pillow lava formation near Schuylerville, New York, United States. It formed about 460 to 440 million years ago in relatively shallow sea water. When Stark's Knob was first discovered, it was thought to be a volcanic plug. It was here during the Saratoga Campaign that General John Stark of New Hampshire cut off the retreat of British General John Burgoyne's army.
The Devonian Mahantango Formation (Dmh) is a mapped bedrock "unit" in Pennsylvania, New Jersey, New York and Maryland. It is named for the North branch of the Mahantango Creek in Perry and Juniata counties in Pennsylvania. It is a member of the Hamilton Group (Dh), along with the underlying the Marcellus Formation (Dm) Shale. South of Tuscarora Mountain in south central Pennsylvania, the lower members of this unit were also mapped as the Montebello Formation.