Columbia (supercontinent)
Encyclopedia
Columbia, also known as Nuna and Hudsonland, was one of Earth's oldest supercontinent
s. It was first proposed by J.J.W. Rogers and M. Santosh (2002) and is thought to have existed approximately 1.8 to 1.5 billion years (Ga) ago in the Paleoproterozoic
Era. Zhao et al. (2002) proposed that the assembly of the supercontinent Columbia (Nuna) was completed by global-scale collisional events during 2.1–1.8 Ga. It consisted of the proto-craton
s that made up the former continents of Laurentia
, Baltica
, Ukrainian Shield
, Amazonia, Australia
, and possibly Siberia
, North China, and Kalaharia as well. The evidence of Columbia's existence is based upon geological
and paleomagnetic
data.
was attached to western North America
, with southern Australia
against western Canada
. Most of South America
spun so that the western edge of modern-day Brazil
lined up with eastern North America
, forming a continental margin
that extended into the southern edge of Scandinavia
.
, Penokean, Taltson–Thelon, Wopmay, Ungava, Torngat, and Nagssugtoqidain Orogens; the Kola, Karelia, Volgo-Uralia, and Sarmatia (Ukrainian) Cratons in Baltica (Eastern Europe) were joined by the 1.9–1.8 Ga Kola–Karelia, Svecofennian, Volhyn-Central Russian, and Pachelma Orogens; the Anabar and Aldan Cratons in Siberia were connected by the 1.9–1.8 Ga Akitkan and Central Aldan Orogens; the East Antarctica and an unknown continental block were joined by the Transantarctic Mountains Orogen; the South and North Indian Blocks were amalgamated along the Central Indian Tectonic Zone; and the Eastern and Western Blocks of the North China Craton were welded together by the ~1.85 Ga Trans-North China Orogen.
, and 1.3-1.2 Ga Elzevirian Belt in North America; the 1.8-1.7 Ga Ketilidian Belt in Greenland; and the 1.8-1.7 Transscandinavian Igneous Belt, 1.7-1.6 Ga Kongsberggian-Gothian Belt, and 1.5-1.3 Ga Southwest Sweden Granitoid Belt in Baltica. Other cratonic blocks also underwent marginal outgrowth at about the same time. In South America, a 1.8-1.3 Ga accretionary zone occurs along the western margin of the Amazonia Craton, represented by the Rio Negro, Juruena, and Rondonian Belts. In Australia, 1.8-1.5 Ga accretionary magmatic belts, including the Arunta, Mount Isa, Georgetown, Coen, and Broken Hill Belts, occur surrounding the southern and eastern margins of the North Australia Craton and the eastern margin of the Gawler Craton. In China, a 1.8-1.4 Ga accretionary magmatic zone, called the Xiong’er belt (Group), extends along the southern margin of the North China Craton.
(Belt-Purcell Supergroup), eastern India (Mahanadi and the Godavari), southern margin of Baltica
(Telemark Supergroup), southeastern margin of Siberia
(Riphean aulacogens), northwestern margin of South Africa
(Kalahari Copper Belt), and northern margin of the North China Block (Zhaertai-Bayan Obo Belt).
The fragmentation corresponded with widespread anorogenic magmatic activity, forming anorthosite
-mangerite
-charnockite
-granite
(AMCG) suites in North America, Baltica, Amazonia, and North China, and continued until the final breakup of the supercontinent at about 1.3-1.2 Ga, marked by the emplacement of the 1.27 Ga Mackenzie
and 1.24 Ga Sudbury
mafic dike swarms in North America
Supercontinent
In geology, a supercontinent is a landmass comprising more than one continental core, or craton. The assembly of cratons and accreted terranes that form Eurasia qualifies as a supercontinent today.-History:...
s. It was first proposed by J.J.W. Rogers and M. Santosh (2002) and is thought to have existed approximately 1.8 to 1.5 billion years (Ga) ago in the Paleoproterozoic
Paleoproterozoic
The Paleoproterozoic is the first of the three sub-divisions of the Proterozoic occurring between . This is when the continents first stabilized...
Era. Zhao et al. (2002) proposed that the assembly of the supercontinent Columbia (Nuna) was completed by global-scale collisional events during 2.1–1.8 Ga. It consisted of the proto-craton
Craton
A craton is an old and stable part of the continental lithosphere. Having often survived cycles of merging and rifting of continents, cratons are generally found in the interiors of tectonic plates. They are characteristically composed of ancient crystalline basement rock, which may be covered by...
s that made up the former continents of Laurentia
Laurentia
Laurentia is a large area of continental craton, which forms the ancient geological core of the North American continent...
, Baltica
Baltica
Baltica is a name applied by geologists to a late-Proterozoic, early-Palaeozoic continent that now includes the East European craton of northwestern Eurasia. Baltica was created as an entity not earlier than 1.8 billion years ago. Before this time, the three segments/continents that now comprise...
, Ukrainian Shield
Ukrainian shield
The Ukrainian Shield is the southwest shield of the East European craton. The Ukrainian Shield and the Voronezh Massif consist of 3.2-3.8 Ga Archaean crust in the southwest and east, and 2.3-2.1 Ga Early Proterozoic orogenic belts....
, Amazonia, Australia
Australia (continent)
Australia is the world's smallest continent, comprising the mainland of Australia and proximate islands including Tasmania, New Guinea, the Aru Islands and Raja Ampat Islands...
, and possibly Siberia
Siberia (continent)
Siberia is the craton located in the heart of the region of Siberia. Siberia or "Angaraland" is today the Central Siberian Plateau...
, North China, and Kalaharia as well. The evidence of Columbia's existence is based upon geological
Geology
Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...
and paleomagnetic
Paleomagnetism
Paleomagnetism is the study of the record of the Earth's magnetic field in rocks. Certain minerals in rocks lock-in a record of the direction and intensity of the magnetic field when they form. This record provides information on the past behavior of Earth's magnetic field and the past location of...
data.
Size and location
Columbia is estimated to have been about 12,900 kilometres from North to South, and about 4,800 km across at its broadest part. The east coast of IndiaIndia
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
was attached to western North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, with southern Australia
Australia (continent)
Australia is the world's smallest continent, comprising the mainland of Australia and proximate islands including Tasmania, New Guinea, the Aru Islands and Raja Ampat Islands...
against western Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
. Most of South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
spun so that the western edge of modern-day Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
lined up with eastern North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, forming a continental margin
Continental margin
The continental margin is the zone of the ocean floor that separates the thin oceanic crust from thick continental crust. Continental margins constitute about 28% of the oceanic area....
that extended into the southern edge of Scandinavia
Scandinavia
Scandinavia is a cultural, historical and ethno-linguistic region in northern Europe that includes the three kingdoms of Denmark, Norway and Sweden, characterized by their common ethno-cultural heritage and language. Modern Norway and Sweden proper are situated on the Scandinavian Peninsula,...
.
Assembly
Columbia was assembled along global-scale 2.0–1.8 Ga collisional orogens and contained almost all of Earth’s continental blocks. The cratonic blocks in South America and West Africa were welded by the 2.1-2.0 Ga Transamazonian and Eburnean Orogens; the Kaapvaal and Zimbabwe Cratons in southern Africa were collided along the ~2.0 Ga Limpopo Belt; the cratonic blocks of Laurentia were sutured along the 1.9–1.8 Ga Trans-HudsonTrans-Hudson orogeny
The Trans-Hudson orogeny, Trans-Hudsonian orogeny, Trans-Hudson orogen , or Trans-Hudson Orogen Transect , , was the major mountain building event that formed the Precambrian Canadian Shield, the North American craton , and the...
, Penokean, Taltson–Thelon, Wopmay, Ungava, Torngat, and Nagssugtoqidain Orogens; the Kola, Karelia, Volgo-Uralia, and Sarmatia (Ukrainian) Cratons in Baltica (Eastern Europe) were joined by the 1.9–1.8 Ga Kola–Karelia, Svecofennian, Volhyn-Central Russian, and Pachelma Orogens; the Anabar and Aldan Cratons in Siberia were connected by the 1.9–1.8 Ga Akitkan and Central Aldan Orogens; the East Antarctica and an unknown continental block were joined by the Transantarctic Mountains Orogen; the South and North Indian Blocks were amalgamated along the Central Indian Tectonic Zone; and the Eastern and Western Blocks of the North China Craton were welded together by the ~1.85 Ga Trans-North China Orogen.
Outgrowth
Following its final assembly at ~1.8 Ga, the supercontinent Columbia underwent long-lived (1.8–1.3 Ga), subduction-related growth via accretion at key continental margins, forming a 1.8-1.3 Ga great magmatic accretionary belt along the present-day southern margin of North America, Greenland, and Baltica. It includes the 1.8-1.7 Ga Yavapai, Central Plains and Makkovikian Belts, 1.7-1.6 Ga Mazatzal and Labradorian Belts, 1.5-1.3 Ga St. Francois and Spavinaw BeltsSpavinaw terrane
The Spavinaw terrane is an occurrence of Proterozoic intrusive and volcanic rocks in the mid-continent region of the United States. The terrane extends across southern Missouri, southern Kansas, northern Arkansas and much of Oklahoma...
, and 1.3-1.2 Ga Elzevirian Belt in North America; the 1.8-1.7 Ga Ketilidian Belt in Greenland; and the 1.8-1.7 Transscandinavian Igneous Belt, 1.7-1.6 Ga Kongsberggian-Gothian Belt, and 1.5-1.3 Ga Southwest Sweden Granitoid Belt in Baltica. Other cratonic blocks also underwent marginal outgrowth at about the same time. In South America, a 1.8-1.3 Ga accretionary zone occurs along the western margin of the Amazonia Craton, represented by the Rio Negro, Juruena, and Rondonian Belts. In Australia, 1.8-1.5 Ga accretionary magmatic belts, including the Arunta, Mount Isa, Georgetown, Coen, and Broken Hill Belts, occur surrounding the southern and eastern margins of the North Australia Craton and the eastern margin of the Gawler Craton. In China, a 1.8-1.4 Ga accretionary magmatic zone, called the Xiong’er belt (Group), extends along the southern margin of the North China Craton.
Fragmentation
Columbia began to fragment about 1.6 Ga ago, associated with continental rifting along the western margin of LaurentiaLaurentia
Laurentia is a large area of continental craton, which forms the ancient geological core of the North American continent...
(Belt-Purcell Supergroup), eastern India (Mahanadi and the Godavari), southern margin of Baltica
Baltica
Baltica is a name applied by geologists to a late-Proterozoic, early-Palaeozoic continent that now includes the East European craton of northwestern Eurasia. Baltica was created as an entity not earlier than 1.8 billion years ago. Before this time, the three segments/continents that now comprise...
(Telemark Supergroup), southeastern margin of Siberia
Siberia
Siberia is an extensive region constituting almost all of Northern Asia. Comprising the central and eastern portion of the Russian Federation, it was part of the Soviet Union from its beginning, as its predecessor states, the Tsardom of Russia and the Russian Empire, conquered it during the 16th...
(Riphean aulacogens), northwestern margin of South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
(Kalahari Copper Belt), and northern margin of the North China Block (Zhaertai-Bayan Obo Belt).
The fragmentation corresponded with widespread anorogenic magmatic activity, forming anorthosite
Anorthosite
Anorthosite is a phaneritic, intrusive igneous rock characterized by a predominance of plagioclase feldspar , and a minimal mafic component...
-mangerite
Mangerite
Mangerite is a plutonic intrusive igneous rock, that is essentially a hypersthene-bearing monzonite. It often occurs in association with norite, anorthosite, charnockite and rapakivi granite in Proterozoic metamorphic belts....
-charnockite
Charnockite
Charnockite is applied to any orthopyroxene-bearing granite, composed mainly of quartz, perthite or antiperthite and orthopyroxene , as an end-member of the charnockite series.-Charnockite series:...
-granite
Granite
Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...
(AMCG) suites in North America, Baltica, Amazonia, and North China, and continued until the final breakup of the supercontinent at about 1.3-1.2 Ga, marked by the emplacement of the 1.27 Ga Mackenzie
Mackenzie dike swarm
The Mackenzie dike swarm, also called the Mackenzie dikes, form a large igneous province in the western Canadian Shield of Canada. It is part of the larger Mackenzie Large Igneous Province and is one of more than three dozen dike swarms in various parts of the Canadian Shield...
and 1.24 Ga Sudbury
Sudbury dike swarm
The Sudbury dike swarm, also called the Sudbury dikes, is a Mesoproterozoic dike swarm in northeastern Ontario, Canada. With an age of 1,238 million years, it is younger than the Sudbury Basin impact event and predates the impact event that formed Lake Wanapitei.-See also:*Volcanism of...
mafic dike swarms in North America