Description

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Source: IUGS

Context

Scientists recently used two independent radioactive dating methods to determine that rocks from the Nuvvuagittuq Greenstone Belt are approximately 4.16 billion years old.

About Nuvvuagittuq Greenstone Belt

The Nuvvuagittuq Greenstone Belt is a collection of ancient rock formations on the eastern shore of Hudson Bay in Quebec, Canada.
These rocks are known for their exceptional age and unique geological features, making the region an important site for research into Earth's early history.
This makes them potentially the oldest known rocks on Earth, challenging previous estimates and rivaling other ancient formations like the Acasta Gneiss Complex (approximately 4 billion years old).

Historical and Geographical Significance

The Nuvvuagittuq Greenstone Belt, previously known as the Porpoise Cove Greenstone Belt, was first mapped in 1965 by the Quebec Ministry of Natural Resources.
The area remained relatively unexplored until the 2000s, when preliminary reports of U-Pb zircon dating in the belt revealed zircons with ages of up to 3,750 Ma. Since then, the Nuvvuagittuq Greenstone Belt has been the focus of extensive research. Scientists continue to disagree about the structure's history and age.
The Nuvvuagittuq Greenstone Belt is part of the Ujaraaluk Mafic Unit, which is located in the Inukjuak subprovince of the Minto Block in North Eastern Superior Province (NESP).
In 2025, the local Inuit tribe that lives in the area revoked sampling permits, citing damage caused by excessive sampling.

What are ultramafic rocks?

Ultramafic rocks are dark-colored igneous or meta-igneous rocks high in magnesium oxide (MgO) and iron oxide (FeO), but low in silica.
They contain more than 90% mafic minerals and are low in potassium.
The Earth's mantle is thought to be primarily composed of ultramafic rock types.
These rocks are commonly found in orogenic (mountain-forming) belts and can provide information about mantle composition and deep Earth processes.

Source: The Hindu

Practice Question:

Q. The Nuvvuagittuq Greenstone Belt is significant in the study of Earth’s early history because:

It is believed to contain some of the oldest rocks on Earth.

It provides evidence of early microbial life.

It is located in the Canadian Shield region.

It lies along the Pacific Ring of Fire.

Which of the statements given above are correct?

A) 1 and 2 only

B) 1, 2 and 3 only

C) 1 and 3 only

D) 1, 2, 3 and 4

Correct Answer:

B) 1, 2 and 3 only

Explanation:

Statement 1: Correct. The Nuvvuagittuq Greenstone Belt contains rocks that are estimated to be about 4.28 billion years old, among the oldest on Earth.

Statement 2: Correct. Some studies suggest the presence of fossilized microbial structures, indicating early life.

Statement 3: Correct. It is located in Quebec, Canada, part of the Canadian Shield.

Statement 4: Incorrect. It is not located along the Pacific Ring of Fire, which is known for active volcanoes and tectonic activity around the Pacific Ocean.