![Rock cycle in Wilson Cycle](https://upload.wikimedia.org/wikipedia/commons/9/99/Rock_cycle_in_Wilson_Cycle.png)
The Wilson Cycle is a model that describes the opening and closing of ocean basins and the
subduction
Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the ...
and divergence of
tectonic plates
Plate tectonics (from the la, label=Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of large te ...
during the assembly and disassembly of
supercontinent
In geology, a supercontinent is the assembly of most or all of Earth's continent, continental blocks or cratons to form a single large landmass. However, some geologists use a different definition, "a grouping of formerly dispersed continents", ...
s. A classic example of the Wilson Cycle is the opening and closing of the
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...
. It has been suggested that Wilson cycles on Earth started about 3
Ga in the
Archean Eon
The Archean Eon ( , also spelled Archaean or Archæan) is the second of four eon (geology), geologic eons of History of Earth, Earth's history, representing the time from . The Archean was preceded by the Hadean Eon and followed by the Proterozo ...
. The Wilson Cycle model was a key development in the theory of
plate tectonics
Plate tectonics (from the la, label=Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of large ...
during the
Plate Tectonics Revolution
The Plate Tectonics Revolution was the scientific and cultural change which developed from the acceptance of the plate tectonics theory. The event was a paradigm shift and scientific revolution.
By 1967 most scientists in geology accepted the theo ...
.
History
The model is named after
John Tuzo Wilson
John Tuzo Wilson (October 24, 1908 – April 15, 1993) was a Canadian geophysicist and geologist who achieved worldwide acclaim for his contributions to the theory of plate tectonics.
''Plate tectonics'' is the scientific theory that the rigi ...
, in recognition of his iconic observation that the present-day
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...
appears along a former suture zone and his development in a classic 1968 paper
of what was later named the "Wilson cycle" in 1975 by
Kevin C. A. Burke
Kevin C. A. Burke (''Kevin Charles Anthony Burke'', November 13, 1929 - March 21, 2018) was a geologist known for his contributions in the theory of plate tectonics. In the course of his life, Burke held multiple professorships, most recent of wh ...
, a colleague and friend of Wilson.
[Wilson, R. W.; Houseman, G. A.; Buiter, S. J. H.; McCaffrey, K. J. W.; Doré, A. G. (2019). "Fifty years of the Wilson Cycle concept in plate tectonics: an overview". Geological Society, London, Special Publications. DOI:https://doi.org/10.1144/SP470-2019-58.]
Theory
The Wilson cycle theory is based upon the idea of an ongoing cycle of ocean closure,
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 prod ...
, and a formation of new ocean on the former
suture zone. The Wilson Cycle can be described in six phases of tectonic plate motion: the separation of a continent (
continent
A continent is any of several large landmasses. Generally identified by convention rather than any strict criteria, up to seven geographical regions are commonly regarded as continents. Ordered from largest in area to smallest, these seven ...
al
rift
In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics.
Typical rift features are a central linear downfaulted depression, called a graben, or more commonly a half-grabe ...
), formation of a young ocean at the seafloor, formation of
ocean basin
In hydrology, an oceanic basin (or ocean basin) is anywhere on Earth that is covered by seawater. Geologically, ocean basins are large geologic basins that are below sea level.
Most commonly the ocean is divided into basins foll ...
s during continental drift, initiation of
subduction
Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the ...
, closure of ocean basins due to oceanic
lithospheric
A lithosphere () is the rigid, outermost rocky shell of a terrestrial planet or natural satellite. On Earth, it is composed of the crust and the portion of the upper mantle that behaves elastically on time scales of up to thousands of years o ...
subduction, and finally,
collision
In physics, a collision is any event in which two or more bodies exert forces on each other in a relatively short time. Although the most common use of the word ''collision'' refers to incidents in which two or more objects collide with great fo ...
of two continents and closure of the ocean basins.
The first three stages (Embryonic, Young, Mature) describe the widening of the ocean and the last three stages (Declining, Terminal, and Relic Scar/Geosuture) describe the closing of the ocean and creation of mountain ranges like the
Himalayas
The Himalayas, or Himalaya (; ; ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the planet's highest peaks, including the very highest, Mount Everest. Over 100 ...
.
In the 21st century, insights from
seismic imaging
Geophysical imaging (also known as geophysical tomography) is a minimally destructive geophysical technique that investigates the subsurface of a terrestrial planet. Geophysical imaging is a noninvasive imaging technique with a high parametrical ...
and other techniques have led to updates to the Wilson Cycle to include relationships between activation of rifting and
mantle plume
A mantle plume is a proposed mechanism of convection within the Earth's mantle, hypothesized to explain anomalous volcanism. Because the plume head partially melts on reaching shallow depths, a plume is often invoked as the cause of volcanic hot ...
s.
Plume-induced rifting and rifting-induced mantle upwelling can explain the high correlation of ages of Large Igneous Provinces and the break-up age for these margins.
Atlantic Ocean Example
![Wilson-cycle hg](https://upload.wikimedia.org/wikipedia/commons/8/88/Wilson-cycle_hg.png)
A case study of the Wilson Cycle can be seen with the development of the Atlantic Ocean. Various parts of the modern day Atlantic Ocean opened at different times over the
Mesozoic
The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceo ...
to
Cenozoic
The Cenozoic ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants, a cooling and drying climate, and the current configura ...
periods following the Wilson Cycle. Seafloor spreading in the Central Atlantic Ocean likely occurred around 134-126 Ma on
Pan-African Orogenic and
Rheic sutures. South Atlantic Ocean
seafloor spreading
Seafloor spreading or Seafloor spread is a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge.
History of study
Earlier theories by Alfred Wegener an ...
began along the
Congo-Sao Francisco Craton around 112 Ma. Following the
North Atlantic Igneous Province
The North Atlantic Igneous Province (NAIP) is a large igneous province in the North Atlantic, centered on Iceland. In the Paleogene, the province formed the Thulean Plateau, a large basaltic lava plain, which extended over at least in area and in ...
eruptions around 55 Ma, the northern Atlantic
passive margin
A passive margin is the transition between oceanic and continental lithosphere that is not an active plate margin. A passive margin forms by sedimentation above an ancient rift, now marked by transitional lithosphere. Continental rifting creat ...
s rifted to their present state.
From the case of the Atlantic Ocean, Wilson Cycle plate margins can broadly be described as having the following attributes:
# Former collision zones, young, and old sutures are where continental break-up can most readily occur;
# Oceanic transfer faults, which can reactivate young and old sutures;
#
Large Igneous Provinces
A large igneous province (LIP) is an extremely large accumulation of igneous rocks, including intrusive (sills, dikes) and extrusive (lava flows, tephra deposits), arising when magma travels through the crust towards the surface. The formation ...
, which do not always lead to continental break-up.
Distinct from supercontinent formation process
A Wilson cycle is not the same as a
supercontinent cycle
The supercontinent cycle is the quasi-periodic aggregation and dispersal of Earth's continental crust. There are varying opinions as to whether the amount of continental crust is increasing, decreasing, or staying about the same, but it is agreed ...
, which is the break-up of one
supercontinent
In geology, a supercontinent is the assembly of most or all of Earth's continent, continental blocks or cratons to form a single large landmass. However, some geologists use a different definition, "a grouping of formerly dispersed continents", ...
and the development of another and takes place on a global scale. The Wilson cycle rarely synchronizes with the timing of a supercontinent cycle.
[{{Citation, last1=Rogers, first1=John J. W., title=Assembly and Dispersal of Supercontinents, date=2004, url=http://dx.doi.org/10.1093/oso/9780195165890.003.0008, work=Continents and Supercontinents, publisher=Oxford University Press, isbn=978-0-19-516589-0, access-date=, last2=Santosh, first2=M., doi=10.1093/oso/9780195165890.003.0008 ] However, both supercontinent cycles and Wilson cycles were involved in the formation of
Pangaea
Pangaea or Pangea () was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from the earlier continental units of Gondwana, Euramerica and Siberia during the Carboniferous approximately 335 million y ...
and of
Rodinia
Rodinia (from the Russian родина, ''rodina'', meaning "motherland, birthplace") was a Mesoproterozoic and Neoproterozoic supercontinent that assembled 1.26–0.90 billion years ago and broke up 750–633 million years ago.
were probably ...
.
References
Scientific models
Plate tectonics