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The rocks are not a "greenstone belt" strictly speaking because they have been so metamorphosed that the original low-grade metamorphic mineral assemblage has been transformed to pyroxene and then retrogressed to hornblende (amphibole) which is black. Instead, geologists refer to such rocks as a supracrustal belt; an assembly of volcano-sedimentary rocks of a common origin for which there is no longer a basement rock contact. The Nuvvuagittuq supracrustal belt is composed of amphibolites mostly metamorphosed basalts and altered tuffs(?) that are poor in CaO (erroneously termed "faux amphibolites"). In addition to these rocks, there are banded iron-formations, quartzites, and some clastic metasediments. The rocks were emplaced around 3.8 billion years ago and carry hints of being derived from some re-worked much older (>4.3 billion years old?) mafic crust. Research continues.
What else can I help you with?
What is the name of a famous rock group?
The Nuvvuagittuq Greenstone on the shore of Hudson Bay, Canada is famous as it is the oldest rock known to man at 4.28 billion years old. Please see the related link for more details.
What is ely greenstone?
Ely Greenstone is a type of greenstone found in the Ely Greenstone Belt in northern Minnesota. It is a metamorphosed volcanic rock that is around 2.7 billion years old, making it one of the oldest rock formations on Earth. Ely Greenstone is known for its unique color and mineral composition.
What type of rock is greenstone?
Greenstone is the rock that has characteristics of both igneous and metamorphic rock.When you break this rock you will see the basaltic composition but it is formed when a basalt is subjected to a different temperature and pressure.
Which rock is most likely the oldest?
Probablly Bill Haley's Comets they are rockabilly they are the first rock n roll band with songs like rock around the clock from 1953
What texture is a greenstone rock?
Greenstone rock can have a smooth texture, with a glossy or waxy appearance. It may also have a fine-grained or compact texture, depending on the specific mineral composition and how it has been weathered or altered over time.
What is the protolith for greenstone?
The protolith for greenstone is usually basaltic or andesitic volcanic rock that has undergone metamorphism, resulting in the formation of chlorite, epidote, and actinolite minerals that give greenstone its characteristic green color. These rocks are typically found in greenschist facies metamorphic environments.
What has the author J Ayer written?
J. Ayer has written: 'Late Archean rock types and controls on gold mineralization in the Southern Abitibi Greenstone Belt of Ontario' -- subject(s): Gold ores, Stratigraphic Geology 'The performance characterisation of solar photovoltaic power conditioners for an improved design' 'Precambrian geology : geological compilation of the Swayze area, Abitibi Greenstone Belt / compilation and interpretation by J.A. Ayer and N.F. Trowell' -- subject(s): Benton township, Foleyet township, Geology - Ontario - Swayze - Abitibi Greenstone Belt, Hardman township, Horwood township, Ivanhoe township, Keith Township, Osway township, Shipley township
Can an igneous rock be changed into a metamorphic rock?
Yes. Among some of the more common changes, granite can become gneiss and basalt can become greenstone.
What is greenstone used for?
Greenstone is a type of rock that is primarily used for creating tools, jewelry, and ornamental objects. It is valued for its durability and attractive green color, making it popular in various cultures for crafting decorative items and ceremonial objects. Additionally, greenstone holds cultural significance in some indigenous communities for its spiritual and symbolic properties.
Is earth 3.1 billion years old?
According to scientists: The current best estimate of the age of the Earth is approx 4.567 billion years. The oldest rocks found to date are the Nuvvuagittuq greenstone which are 4.28 billion years old and were found on the shore of Hudson Bay in Canada. The oldest mineral ever dated was a zircon found in a rock in Australia and was dated as being around 4.4 billion years old. Please see the related links.
What is the oldest Earth rock?
Currently the oldest insitu rock layers of terrestrial origin were discovered by Dr. Jonathan O'Neil and his colleagues, whose work published in September of 2008, revealed rocks as old as 4.28 billion years of age in Northern Quebec, along the Hudson's Bay coast, 40 km south of Inukjuak. This area is known as the Nuvvuagittuq greenstone belt. They were dated by measuring the decay of the element neodymium-142 which was present in the rock.However this is either the oldest rock material of Earth origin or the oldest rock material found on Earth.For further information, please see the related links below.For information on the oldest material of terrestrial origin and the oldest material found on Earth please see the related questions.
Basalt can change into what metamorphic rock?
When basalt undergoes metamorphism, it can change into a metamorphic rock called greenstone. Greenstone is a fine-grained metamorphic rock that forms from the alteration of basalt through metamorphic processes like recrystallization and the growth of new minerals.
