Taconic Orogeny

Taconic Orogeny
Mountain-building event that affected the Appalachian Geosyncline along the eastern coast of the U.S. Evidence for the orogeny is most pronounced in the northern Appalachian Mountains, but its effects can be noted as far away as Tennessee and Georgia.

Events ascribed to it include the development of New York's Taconic Range and Vermont's Green Mountains. Originally thought to have occurred at approximately the Ordovician-Silurian boundary (с 443 million years ago), it is now generally considered to have consisted of several pulses from the mid-Ordovician to the early Silurian Period.

* * *

▪ geological event
      first of three mountain-building events forming the Appalachian Mountains in eastern North America, the Acadian (Acadian orogeny) and Alleghenian (Alleghenian orogeny) orogenies being the second and third events, respectively. Originally viewed as a single event, the Taconic orogeny is now known to consist of at least three episodes. The first took place in the Early Ordovician (Ordovician Period) Epoch near Maine and Newfoundland. The second was centred on eastern Tennessee in the Middle Ordovician Epoch. The third occurred during the Late Ordovician Epoch, principally in eastern Virginia, Pennsylvania, and New York.

      The three episodes are thought to represent the oblique collision of a terrane (a crustal block or formation of related rocks) with the eastern edge of North America. In the Appalachians, the Taconic orogeny produced angular unconformities (interruptions in the deposition of sedimentary rock) in the Appalachian Basin and the Taconic Allochthon in New York, and it also caused igneous (igneous rock) intrusions and regional metamorphism (metamorphic rock) in the northern and southern Appalachians. Flexure of North America during the Taconic collisions produced deep sedimentary basins that accumulated up to 300 metres (about 1,000 feet) of sediment in some areas, such as the Queenston Delta in New York and the Blount Group in eastern Tennessee. More-distant effects included gentle uplift of the Nashville Dome and Cincinnati Arch. The third episode of the Taconic orogeny triggered a regional extinction of many marine invertebrates (invertebrate) in eastern North America.

* * *

Universalium. 2010.

Игры ⚽ Нужна курсовая?

Look at other dictionaries:

  • Taconic orogeny — 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… …   Wikipedia

  • Taconic — can refer to:*Taconic Mountains, part of the Appalachian Mountains, running through eastern New York State, western Connecticut, and Massachusetts, as well as southwestern Vermont in the United States *Taconic orogeny, a great mountain building… …   Wikipedia

  • orogeny — orogenic /awr euh jen ik, or euh /, orogenetic, adj. /aw roj euh nee, oh roj /, n. Geol. the process of mountain making or upheaval. Also called orogenesis /awr euh jen euh sis, or euh /. [1885 90; ORO 1 + GENY] * * * I Mountain building event,… …   Universalium

  • Taconic Mountains — The Taconic Mountains are a physiographic section of the larger New England province and part of the Appalachian Mountains, running along the eastern border of New York State, United States and adjacent New England from northwest Connecticut to… …   Wikipedia

  • Orogeny — Geologic provinces of the world (USGS)   Shield …   Wikipedia

  • Acadian orogeny — The Acadian orogeny is a middle Paleozoic deformation, especially in the northern Appalachians, between New York and Newfoundland. In Gaspé and adjacent areas, its climax is dated as early in the Late Devonian, but deformational, plutonic, and… …   Wikipedia

  • Iapetus Ocean — The Iapetus Ocean was an ocean that existed in the Southern Hemisphere between Laurentia (Scotland and North America) and Baltica (Scandinavia) between 400 and 600 million years ago. As a sort of precursor of the Atlantic Ocean, it was named for… …   Wikipedia

  • Geology of Pennsylvania — The Geology of Pennsylvania consists of six distinct physiographic provinces, three of which are subdivided into different sections. Each province has its own economic advantages and geologic hazards and play an important role in shaping every… …   Wikipedia

  • Ordovician Period — Interval of geologic time, 490–443 million years ago, the second oldest period of the Paleozoic Era. It follows the Cambrian and precedes the Silurian. During the Ordovician, many of the landmasses were aligned in the tropics. Life was dominated… …   Universalium

  • Geologic time scale — This clock representation shows some of the major units of geological time and definitive events of Earth history. The Hadean eon represents the time before fossil record of life on Earth; its upper boundary is now regarded as 4.0 Ga.[1] Other… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”