What is Hercynian system?

The Variscan or Hercynian orogeny was a geologic mountain-building event caused by Late Paleozoic continental collision between Euramerica (Laurussia) and Gondwana to form the supercontinent of Pangaea.

What is Hercynian period?

The Hercynian, or Variscan, orogenic belt evolved during the Devonian and Carboniferous periods, from about 419 to 299 million years ago.

What happened in the Variscan orogeny?

By the late Palaeozoic (250 million years ago), the continents had converged to form a supercontinent, called Pangea. The collisions which brought this about are known as the Variscan (sometimes Hercynian or Armorican) orogeny, which took place over about 100 million years.

Where are the Hercynian Mountains?

The Variscan (often termed Hercynian) orogeny spans most of central and south-eastern Europe from South Portugal to Poland and beyond into the Balkans and Turkey. It is a collage of microcontinents which drifted off from the northern margin of Gondwana and includes Avalonia and the Armorican Terranes Assemblage (ATA).

What caused the Ouachita orogeny?

Collision. South America approached Laurentia as the intervening oceanic crust was subducted. The collision of South American and Laurentian continental crust compressed and uplifted the region to form the Ouachita Mountains.

When did the Rheic Ocean close?

In Mexico and Europe, closure of the Rheic Ocean was accompanied in the Late Devonian and Early Carboniferous by the emplacement of rare ophiolites and associated high-pressure rocks (e.g., Murphy et al., 2009b).

What is Himalayan orogeny?

The Himalayas, which stretch over 2400 km between the Namcha Barwa syntaxis in Tibet and the Nanga Parbat syntaxis in Kashmir, are the result of an ongoing orogeny — the collision of the continental crust of two tectonic plates namely the Indian Plate thrusting into the Eurasian Plate.

How did the Caledonian orogeny form?

The Caledonian orogeny encompasses events that occurred from the Ordovician to Early Devonian, roughly 490–390 million years ago (Ma). It was caused by the closure of the Iapetus Ocean when the continents and terranes of Laurentia, Baltica and Avalonia collided.

What is the Grenville orogeny and how did it affect Laurentia?

The Grenville orogeny was a long-lived Mesoproterozoic mountain-building event associated with the assembly of the supercontinent Rodinia. 1250–980 Ma) is found worldwide, but generally only events which occurred on the southern and eastern margins of Laurentia are recognized under the “Grenville” name.

How did the Laramide orogeny form?

The Laramide orogeny occurred from approximately 70 million years ago to 40 million years ago during a period when the Farallon oceanic plate was subducting rapidly beneath the western coast of the U.S. The most unusual aspect of the Laramide orogeny is the fact that the mountain ranges created during this period were …

When did the Iapetus Ocean open?

about 550 Ma
The southern Iapetus Ocean opened between Laurentia and southwestern Gondwana (now South America) about 550 Ma in the Ediacaran–Cambrian transition. At the time it did so the Adamastor Ocean further east closed.

Where was the subsidence of the Hercynian orogeny?

Southwestern and southeastern Ciscaucasia lie on the margins of a vast downfold in the Earth’s surface that arose later in the Alpine orogeny, producing, concurrently, broad subsidence on the lower courses of… …the structural upheavals of the Hercynian orogeny (about 250 million years ago).

Where does the word Hercynian come from in geology?

Hercynian, on the other hand, derives from the Hercynian Forest. Both words were descriptive terms of strike directions observed by geologists in the field, variscan for southwest to northeast, hercynian for northwest to southeast.

How did the Hercynian orogeny affect the Alps?

The Hercynian, or Variscan, orogeny followed about 300 million years ago, affecting subparallel regions and the Urals and European Alps. In fact, the shield margins appear to have been subjected to a more or less constant battering by forces both destroying and rebuilding the margins of…

When to use Hercynian as a synonym for Variscan?

Today, Hercynian is often used as a synonym for Variscan but is somewhat less used than the latter. In the United States, it is used only for European orogenies; the contemporaneous and genetically linked mountain-building phases in the Appalachian Mountains have different names.