Allochton on:
[Wikipedia]
[Google]
[Amazon]
upright=1.6, Schematic overview of a thrust system. The hanging wall block is (when it has reasonable proportions) called a nappe._If_an_erosional_hole_is_created_in_the_nappe_that_is_called_a_window_(geology).html" "title="erosion.html" ;"title="nappe. If an erosion">nappe. If an erosional hole is created in the nappe that is called a window (geology)">window
A window is an opening in a wall, door, roof, or vehicle that allows the exchange of light and may also allow the passage of sound and sometimes air. Modern windows are usually glazed or covered in some other transparent or translucent mat ...
. A
klippe
350px, Schematic overview of a thrust system. The shaded material is called a window_(geology).html"_;"title="nappe._The_erosional_hole_is_called_a__window_(geology)">window_or_fenster._The_klippe_is_the_isolated_block_of_the_nappe_overlying_aut ...
is a solitary outcrop of the nappe in the middle of autochthonous material.
An allochthon, or an allochthonous block, is a large block of rock which has been moved from its original site of formation, usually by
low angle thrust faulting. An allochthon which is isolated from the rock that pushed it into position is called a
klippe
350px, Schematic overview of a thrust system. The shaded material is called a window_(geology).html"_;"title="nappe._The_erosional_hole_is_called_a__window_(geology)">window_or_fenster._The_klippe_is_the_isolated_block_of_the_nappe_overlying_aut ...
. If an allochthon has a "hole" in it so that one can view the
autochthon (geology), autochthon beneath the allochthon, the hole is called a "
window
A window is an opening in a wall, door, roof, or vehicle that allows the exchange of light and may also allow the passage of sound and sometimes air. Modern windows are usually glazed or covered in some other transparent or translucent mat ...
" (or Fenster). Etymology: Greek; 'allo' = other, and 'chthon' = earth. In generalized terms, the term is applied to any geologic units that originated at a distance from their present location For comparison, see also
Autochthon.
In the United States there are three notable allochthons; all of which were displaced nearly 50 km (31 miles) along thrust faults. The
Golconda
Fort (Telugu: గోల్కొండ, romanized: ''Gōlkōnḍa'') is a historic fortress and ruined city located in Hyderabad, Telangana, India. It was originally called Mankal. The fort was originally built by Kakatiya ruler Pratāparu ...
and Robert Mountains allochthons are both found in
Nevada
Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. N ...
, a product of the
Antler Orogeny in the Late-Devonian period. The third is the Taconic allochthons found in
New York
New York most commonly refers to:
* New York City, the most populous city in the United States, located in the state of New York
* New York (state), a state in the northeastern United States
New York may also refer to:
Film and television
* '' ...
,
Massachusetts
Massachusetts (Massachusett: ''Muhsachuweesut Massachusett_writing_systems.html" ;"title="nowiki/> məhswatʃəwiːsət.html" ;"title="Massachusett writing systems">məhswatʃəwiːsət">Massachusett writing systems">məhswatʃəwiːsət'' En ...
and
Vermont
Vermont () is a U.S. state, state in the northeast New England region of the United States. Vermont is bordered by the states of Massachusetts to the south, New Hampshire to the east, and New York (state), New York to the west, and the Provin ...
formed from the collision of the Taconic magmatic arc with the super-continent
Laurentia
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, althoug ...
in the Late-Cambrian period.
See also
*
Accretion (geology)
Accretion, in geology, is a process by which material is added to a tectonic plate at a subduction zone, frequently on the edge of existing continental landmasses. The added material may be sediment, volcanic arcs, seamounts, oceanic crust or ...
*
Continental collision
In geology, continental collision is a phenomenon of plate tectonics that occurs at convergent boundaries. Continental collision is a variation on the fundamental process of subduction, whereby the subduction zone is destroyed, mountains produ ...
*
Orogeny
Orogeny is a mountain building process. An orogeny is an event that takes place at a convergent plate margin when plate motion compresses the margin. An '' orogenic belt'' or ''orogen'' develops as the compressed plate crumples and is uplifted ...
References
Structural geology
{{Geology-stub
