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The "Taconic Unconformity" is an angular unconformity exposed from eastern New York State to the Gaspe peninsula. As the Taconic orogeny subsided in early Silurian time, uplifts and folds in the Hudson Valley region were beveled by erosion. Upon this surface sediments began to accumulate, derived from remaining uplifts in the New England region.
Taconic orogeny. Algoman orogeny, also known as Kenoran orogeny – Late Archaean episode of mountain building in what is now North America – Superior province, South Dakota to Lake Huron, late Archean Eon (2700–2500 Ma) Wopmay orogeny – Mountain-building event in northern Canada – Along western edge of Canadian shield, (2100–1900 Ma)
In the west, the Iapetus Ocean closed with the Taconic orogeny (480-430 million years ago), when the volcanic island arc collided with Laurentia. Some authors consider the oceanic basin south of the island arc also a part of the Iapetus, this branch closed during the later Acadian orogeny, when Avalonia collided with Laurentia. [citation needed]
After the Grenville orogeny, the direction of the continental drift reversed, and Rodinia began to break up. The mountains formed during the Grenvillian era underwent erosion from weathering, glaciation, and other natural processes, resulting in the leveling of the landscape. The eroded sediments from these mountains contributed to the ...
The Taconic Unconformity, near Catskill, NY. The Taconic unconformity is a major unconformity created during the Taconic orogeny, exposed from eastern New York State to the Gaspe peninsula. [1] The orogeny was a long one that comprised multiple bursts; it primarily dated to the end of the Ordovician, and the underlying rocks are primarily this age.
Laurentia basement rocks. Laurentia or the North American Craton is a large continental craton that forms the ancient geological core of North America.Many times in its past, Laurentia has been a separate continent, as it is now in the form of North America, although originally it also included the cratonic areas of Greenland and the Hebridean Terrane in northwest Scotland.
The Taconic orogeny, between 490 and 445 million years ago, the Acadian orogeny, from 410 to 380 million years ago, and the Alleghanian orogeny from 325 to 220 million years ago pushed up towering mountain ranges. Extensive erosion of these mountains shed sediments westward into a shallow sea in Arizona.
In the east these carbonates gradually become shales, representing sediments eroded from highlands created in the Taconic orogeny. [2] The Tippecanoe sequence may have been the deepest of the Paleozoic. At one point during the Silurian period, the Taconic highlands, were the only part of North America that was not submerged. [3]