The Abitibi greenstone belt is a 2,800-to-2,600-million-year-old
greenstone belt
Greenstone belts are zones of variably metamorphosed mafic to ultramafic volcanic sequences with associated sedimentary rocks that occur within Archaean and Proterozoic cratons between granite and gneiss bodies.
The name comes from the gree ...
that spans across the
Ontario
Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central Ca ...
–
Quebec
Quebec ( ; )According to the Canadian government, ''Québec'' (with the acute accent) is the official name in Canadian French and ''Quebec'' (without the accent) is the province's official name in Canadian English is one of the thirte ...
border in
Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by to ...
.
It is mostly made of
volcanic rocks, but also includes
ultramafic rock
Ultramafic rocks (also referred to as ultrabasic rocks, although the terms are not wholly equivalent) are igneous and meta-igneous rocks with a very low silica content (less than 45%), generally >18% MgO, high FeO, low potassium, and are compose ...
s,
mafic
A mafic mineral or rock is a silicate mineral or igneous rock rich in magnesium and iron. Most mafic minerals are dark in color, and common rock-forming mafic minerals include olivine, pyroxene, amphibole, and biotite. Common mafic rocks in ...
intrusion
In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth. Intrusions have a wide variety of forms and com ...
s,
granitoid rocks, and early and middle
Precambrian
The Precambrian (or Pre-Cambrian, sometimes abbreviated pꞒ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of th ...
sediments.
Archean greenstone belt
Retrieved on 2007-09-26
Geographical extent
The Abitibi greenstone belt is one of the world's largest Archean
The Archean Eon ( , also spelled Archaean or Archæan) is the second of four geologic eons of Earth's history, representing the time from . The Archean was preceded by the Hadean Eon and followed by the Proterozoic.
The Earth during the Arc ...
greenstone belts. It represents a series of subterranes that exhibit similar geological, geochemical, and isotopical signatures similar to those formed during the evolution of paired active-arc-back-arc systems. The huge 2,707-to-2,696-million-year-old Blake River Megacaldera Complex
The Blake River Megacaldera Complex is a giant subaqueous caldera cluster or a nested caldera system that spans across the Ontario–Quebec border in Canada.
The caldera complex is around 2.7 billion years old, consisting of a series of overlappi ...
is within the belt.
See also
* Abitibi gold belt
The Abitibi gold belt is a region of Canada that extends from Wawa, Ontario to Val-d'Or, Quebec. Located within the mineral-rich Abitibi greenstone belt, the gold belt is an established gold mining district having produced over 100 mines, and ...
* List of greenstone belts
* Volcanism of Canada
Volcanism, Volcanic activity is a major part of the geology of Canada and is characterized by many types of volcanic landform, including lava flows, volcanic plateaus, lava domes, cinder cones, stratovolcanoes, shield volcanoes, submarine volcano ...
* Volcanism of Eastern Canada
References
Greenstone belts
Neoarchean volcanism
Precambrian Canada
Volcanism of Ontario
Volcanism of Quebec
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