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How did the Taconic orogeny change eastern North America during the Ordovician Period?
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Ordovician Period
The distribution of landmasses, mountainous regions, shallow seas, and deep ocean basins during the Ordovician Period. Included in the paleogeographic reconstruction are the locations of the interval's subduction zones.
The Taconic orogeny was a series of at least three mountain-building events during the Ordovician Period caused by the oblique collision of terranesâsuch as volcanic island arcsâwith the eastern edge of the North American continent, known as Laurentia.123
This tectonic activity significantly transformed the region in several ways:
- Structural Deformation: The collisions produced regional metamorphism, igneous intrusions, and angular unconformities in the Appalachian region.1
- Basin Formation: The flexure of the North American crust created deep sedimentary basins along the eastern margin. These basins accumulated massive amounts of sediment, such as the Queenston Delta in New York and the Blount Group in Tennessee, with some deposits reaching over 3,000 metres in thickness.12
- Regional Uplift: The orogeny caused distant effects, including the gentle uplift of the Cincinnati Arch and the Nashville Dome.1
- Biological Impact: The third episode of the orogeny is associated with a regional extinction event that affected many marine invertebrates in eastern North America.1