Latest news with #HadeanEon
Yahoo
08-07-2025
- Science
- Yahoo
Scientists unlock secrets of oldest rocks on Earth
Earth formed about 4.6 billion years ago, during the geological eon known as the Hadean. The name 'Hadean' comes from the Greek god of the underworld, reflecting the extreme heat that likely characterised the planet at the time. By 4.35 billion years ago, the Earth might have cooled down enough for the first crust to form and life to emerge. However, very little is known about this early chapter in Earth's history, as rocks and minerals from that time are extremely rare. This lack of preserved geological records makes it difficult to reconstruct what the Earth looked like during the Hadean Eon, leaving many questions about its earliest evolution unanswered. We are part of a research team that has confirmed the oldest known rocks on Earth are located in northern Québec. Dating back 4.3 billion years, these rocks provide a rare and invaluable glimpse into the origins of our planet. The Hadean Eon is the first period in the geological timescale, spanning from Earth's formation 4.6 billion years ago and ending around 4.03 billion years ago. The oldest terrestrial materials ever dated by scientists are extremely rare zircon minerals that were discovered in western Australia. These zircons were formed as early as 4.4 billion years ago, and while their host rock eroded away, the durability of zircons allowed them to be preserved for a long time. Studies of these zircon minerals has given us clues about the Hadean environment, and the formation and evolution of Earth's oldest crust. The zircons' chemistry suggests that they formed in magmas produced by the melting of sediments deposited at the bottom of an ancient ocean. This suggests that the zircons are evidence that the Hadean Eon cooled rapidly, and liquid water oceans were formed early on. Other research on the Hadean zircons suggests that the Earth's earliest crust was mafic (rich in magnesium and iron). Until recently, however, the existence of that crust remained to be confirmed. In 2008, a study led by associate professor Jonathan O'Neil (then a McGill University doctoral student) proposed that rocks of this ancient crust had been preserved in northern Québec and were the only known vestige of the Hadean. Since then, the age of those rocks — found in the Nuvvuagittuq Greenstone Belt — has been controversial and the subject of ongoing scientific debate. The Nuvvuagittuq Greenstone Belt is located in the northernmost region of Québec, in the Nunavik region above the 55th parallel. Most of the rocks there are metamorphosed volcanic rocks, rich in magnesium and iron. The most common rocks in the belt are called the Ujaraaluk rocks, meaning 'big old solid rock' in Inuktitut. The age of 4.3 billion years was proposed after variations in neodymium-142 were detected, an isotope produced exclusively during the Hadean through the radioactive decay of samarium-146. The relationship between samarium and neodymium isotope abundances had been previously used to date meteorites and lunar rocks, but before 2008 had never been applied to Earth rocks. This interpretation, however, was challenged by several research groups, some of whom studied zircons within the belt and proposed a younger age of at most 3.78 billion years, placing the rocks in the Archean Eon instead. In the summer of 2017, we returned to the Nuvvuagittuq belt to take a closer look at the ancient rocks. This time, we collected intrusive rocks — called metagabbros — that cut across the Ujaraaluk rock formation, hoping to obtain independent age constraints. The fact that these newly studied metagabbros are in intrusion in the Ujaraaluk rocks implies that the latter must be older. The project was led by masters student Chris Sole at the University of Ottawa, who joined us in the field. Back in the laboratory, we collaborated with French geochronologist Jean-Louis Paquette. Additionally, two undergraduate students — David Benn (University of Ottawa) and Joeli Plakholm (Carleton University) participated to the project. We combined our field observations with petrology, geochemistry, geochronology and applied two independent samarium-neodymium age dating methods, dating techniques used to assess the absolute ages of magmatic rocks, before these become metamorphic rocks. Both assessments yielded the same result: the intrusive rocks are 4.16 billion years old. Since these metagabbros cut across the Ujaraaluk formation, the Ujaraaluk rocks must be even older, placing them firmly in the Hadean Eon. Studying the Nuvvuagittuq rocks, the only preserved rocks from the Hadean, provides a unique opportunity to learn about the earliest history of our planet. They can help us understand how the first continents formed, and how and when Earth's environment evolved to become habitable. Hanika Rizo is an Associate Professor in the Department of Earth Sciences at Carleton University Jonathan O'Neil is a Professor in Earth and Environmental Sciences at L'Université d'Ottawa/University of Ottawa This article was originally published by The Conversation and is republished under a Creative Commons licence. Read the original article
Gulf Today
07-07-2025
- Science
- Gulf Today
Scientists unlock secrets of oldest rocks on Earth
Hanika Rizo and Jonathan O'Neil, The Independent Earth formed about 4.6 billion years ago, during the geological eon known as the Hadean. The name "Hadean" comes from the Greek god of the underworld, reflecting the extreme heat that likely characterised the planet at the time. By 4.35 billion years ago, the Earth might have cooled down enough for the first crust to form and life to emerge. However, very little is known about this early chapter in Earth's history, as rocks and minerals from that time are extremely rare. This lack of preserved geological records makes it difficult to reconstruct what the Earth looked like during the Hadean Eon, leaving many questions about its earliest evolution unanswered. We are part of a research team that has confirmed the oldest known rocks on Earth are located in northern Québec. Dating back 4.3 billion years, these rocks provide a rare and invaluable glimpse into the origins of our planet. Remains from the Hadean EonThe Hadean Eon is the first period in the geological timescale, spanning from Earth's formation 4.6 billion years ago and ending around 4.03 billion years ago. The oldest terrestrial materials ever dated by scientists are extremely rare zircon minerals that were discovered in western Australia. These zircons were formed as early as 4.4 billion years ago, and while their host rock eroded away, the durability of zircons allowed them to be preserved for a long time. Studies of these zircon minerals has given us clues about the Hadean environment, and the formation and evolution of Earth's oldest crust. The zircons' chemistry suggests that they formed in magmas produced by the melting of sediments deposited at the bottom of an ancient ocean. This suggests that the zircons are evidence that the Hadean Eon cooled rapidly, and liquid water oceans were formed early on. Other research on the Hadean zircons suggests that the Earth's earliest crust was mafic (rich in magnesium and iron). Until recently, however, the existence of that crust remained to be confirmed. In 2008, a study led by associate professor Jonathan O'Neil (then a McGill University doctoral student) proposed that rocks of this ancient crust had been preserved in northern Québec and were the only known vestige of the Hadean. Since then, the age of those rocks — found in the Nuvvuagittuq Greenstone Belt — has been controversial and the subject of ongoing scientific debate. 'Big, old solid rock'The Nuvvuagittuq Greenstone Belt is located in the northernmost region of Québec, in the Nunavik region above the 55th parallel. Most of the rocks there are metamorphosed volcanic rocks, rich in magnesium and iron. The most common rocks in the belt are called the Ujaraaluk rocks, meaning "big old solid rock" in Inuktitut. The age of 4.3 billion years was proposed after variations in neodymium-142 were detected, an isotope produced exclusively during the Hadean through the radioactive decay of samarium-146. The relationship between samarium and neodymium isotope abundances had been previously used to date meteorites and lunar rocks, but before 2008 had never been applied to Earth rocks. This interpretation, however, was challenged by several research groups, some of whom studied zircons within the belt and proposed a younger age of at most 3.78 billion years, placing the rocks in the Archean Eon instead. Confirming the Hadean AgeIn the summer of 2017, we returned to the Nuvvuagittuq belt to take a closer look at the ancient rocks. This time, we collected intrusive rocks — called metagabbros — that cut across the Ujaraaluk rock formation, hoping to obtain independent age constraints. The fact that these newly studied metagabbros are in intrusion in the Ujaraaluk rocks implies that the latter must be older. The project was led by masters student Chris Sole at the University of Ottawa, who joined us in the field. Back in the laboratory, we collaborated with French geochronologist Jean-Louis Paquette. Additionally, two undergraduate students — David Benn (University of Ottawa) and Joeli Plakholm (Carleton University) participated to the project. We combined our field observations with petrology, geochemistry, geochronology and applied two independent samarium-neodymium age dating methods, dating techniques used to assess the absolute ages of magmatic rocks, before these become metamorphic rocks. Both assessments yielded the same result: the intrusive rocks are 4.16 billion years old. The oldest rocksSince these metagabbros cut across the Ujaraaluk formation, the Ujaraaluk rocks must be even older, placing them firmly in the Hadean Eon. Studying the Nuvvuagittuq rocks, the only preserved rocks from the Hadean, provides a unique opportunity to learn about the earliest history of our planet. They can help us understand how the first continents formed, and how and when Earth's environment evolved to become habitable. Hanika Rizo is an Associate Professor in the Department of Earth Sciences at Carleton University
NDTV
07-07-2025
- Science
- NDTV
Oldest Rock On Earth Confirmed To Be Over 4 Billion Years Old
Ottawa: Earth formed about 4.6 billion years ago, during the geological eon known as the Hadean. The name "Hadean" comes from the Greek god of the underworld, reflecting the extreme heat that likely characterized the planet at the time. By 4.35 billion years ago, the Earth might have cooled down enough for the first crust to form and life to emerge. However, very little is known about this early chapter in Earth's history, as rocks and minerals from that time are extremely rare. This lack of preserved geological records makes it difficult to reconstruct what the Earth looked like during the Hadean Eon, leaving many questions about its earliest evolution unanswered. We are part of a research team that has confirmed the oldest known rocks on Earth are located in northern Québec. Dating back more than four billion years, these rocks provide a rare and invaluable glimpse into the origins of our planet. Remains from the Hadean Eon The Hadean Eon is the first period in the geological timescale, spanning from Earth's formation 4.6 billion years ago and ending around 4.03 billion years ago. The oldest terrestrial materials ever dated by scientists are extremely rare zircon minerals that were discovered in western Australia. These zircons were formed as early as 4.4 billion years ago, and while their host rock eroded away, the durability of zircons allowed them to be preserved for a long time. Studies of these zircon minerals has given us clues about the Hadean environment, and the formation and evolution of Earth's oldest crust. The zircons' chemistry suggests that they formed in magmas produced by the melting of sediments deposited at the bottom of an ancient ocean. This suggests that the zircons are evidence that the Hadean Eon cooled rapidly, and liquid water oceans were formed early on. Other research on the Hadean zircons suggests that the Earth's earliest crust was mafic (rich in magnesium and iron). Until recently, however, the existence of that crust remained to be confirmed. In 2008, a study led by one of us - associate professor Jonathan O'Neil (then a McGill University doctoral student) - proposed that rocks of this ancient crust had been preserved in northern Québec and were the only known vestige of the Hadean. Since then, the age of those rocks - found in the Nuvvuagittuq Greenstone Belt - has been controversial and the subject of ongoing scientific debate. 'Big, old solid rock' The Nuvvuagittuq Greenstone Belt is located in the northernmost region of Québec, in the Nunavik region above the 55th parallel. Most of the rocks there are metamorphosed volcanic rocks, rich in magnesium and iron. The most common rocks in the belt are called the Ujaraaluk rocks, meaning "big old solid rock" in Inuktitut. The age of 4.3 billion years was proposed after variations in neodymium-142 were detected, an isotope produced exclusively during the Hadean through the radioactive decay of samarium-146. The relationship between samarium and neodymium isotope abundances had been previously used to date meteorites and lunar rocks, but before 2008 had never been applied to Earth rocks. This interpretation, however, was challenged by several research groups, some of whom studied zircons within the belt and proposed a younger age of at most 3.78 billion years, placing the rocks in the Archean Eon instead. Confirming the Hadean Age In the summer of 2017, we returned to the Nuvvuagittuq belt to take a closer look at the ancient rocks. This time, we collected intrusive rocks - called metagabbros - that cut across the Ujaraaluk rock formation, hoping to obtain independent age constraints. The fact that these newly studied metagabbros are in intrusion in the Ujaraaluk rocks implies that the latter must be older. The project was led by masters student Chris Sole at the University of Ottawa, who joined us in the field. Back in the laboratory, we collaborated with French geochronologist Jean-Louis Paquette. Additionally, two undergraduate students - David Benn (University of Ottawa) and Joeli Plakholm (Carleton University) participated to the project. We combined our field observations with petrology, geochemistry, geochronology and applied two independent samarium-neodymium age dating methods, dating techniques used to assess the absolute ages of magmatic rocks, before they became metamorphic rocks. Both assessments yielded the same result: the intrusive rocks are 4.16 billion years old. The oldest rocks Since these metagabbros cut across the Ujaraaluk formation, the Ujaraaluk rocks must be even older, placing them firmly in the Hadean Eon. Studying the Nuvvuagittuq rocks, the only preserved rocks from the Hadean, provides a unique opportunity to learn about the earliest history of our planet. They can help us understand how the first continents formed, and how and when Earth's environment evolved to become habitable. (Disclaimer Statement: Hanika Rizo receives funding from the Natural Sciences and Engineering Research Council of Canada (NSERC). Jonathan O'Neil receives funding from the Natural Sciences and Engineering Research Council of Canada.)
The Independent
07-07-2025
- Science
- The Independent
Scientists unlock secrets of oldest rocks on Earth
Earth formed about 4.6 billion years ago, during the geological eon known as the Hadean. The name 'Hadean' comes from the Greek god of the underworld, reflecting the extreme heat that likely characterised the planet at the time. By 4.35 billion years ago, the Earth might have cooled down enough for the first crust to form and life to emerge. However, very little is known about this early chapter in Earth's history, as rocks and minerals from that time are extremely rare. This lack of preserved geological records makes it difficult to reconstruct what the Earth looked like during the Hadean Eon, leaving many questions about its earliest evolution unanswered. We are part of a research team that has confirmed the oldest known rocks on Earth are located in northern Québec. Dating back 4.3 billion years, these rocks provide a rare and invaluable glimpse into the origins of our planet. Remains from the Hadean Eon The Hadean Eon is the first period in the geological timescale, spanning from Earth's formation 4.6 billion years ago and ending around 4.03 billion years ago. The oldest terrestrial materials ever dated by scientists are extremely rare zircon minerals that were discovered in western Australia. These zircons were formed as early as 4.4 billion years ago, and while their host rock eroded away, the durability of zircons allowed them to be preserved for a long time. Studies of these zircon minerals has given us clues about the Hadean environment, and the formation and evolution of Earth's oldest crust. The zircons' chemistry suggests that they formed in magmas produced by the melting of sediments deposited at the bottom of an ancient ocean. This suggests that the zircons are evidence that the Hadean Eon cooled rapidly, and liquid water oceans were formed early on. Other research on the Hadean zircons suggests that the Earth's earliest crust was mafic (rich in magnesium and iron). Until recently, however, the existence of that crust remained to be confirmed. In 2008, a study led by associate professor Jonathan O'Neil (then a McGill University doctoral student) proposed that rocks of this ancient crust had been preserved in northern Québec and were the only known vestige of the Hadean. Since then, the age of those rocks — found in the Nuvvuagittuq Greenstone Belt — has been controversial and the subject of ongoing scientific debate. 'Big, old solid rock' The Nuvvuagittuq Greenstone Belt is located in the northernmost region of Québec, in the Nunavik region above the 55th parallel. Most of the rocks there are metamorphosed volcanic rocks, rich in magnesium and iron. The most common rocks in the belt are called the Ujaraaluk rocks, meaning 'big old solid rock' in Inuktitut. The age of 4.3 billion years was proposed after variations in neodymium-142 were detected, an isotope produced exclusively during the Hadean through the radioactive decay of samarium-146. The relationship between samarium and neodymium isotope abundances had been previously used to date meteorites and lunar rocks, but before 2008 had never been applied to Earth rocks. This interpretation, however, was challenged by several research groups, some of whom studied zircons within the belt and proposed a younger age of at most 3.78 billion years, placing the rocks in the Archean Eon instead. Confirming the Hadean Age In the summer of 2017, we returned to the Nuvvuagittuq belt to take a closer look at the ancient rocks. This time, we collected intrusive rocks — called metagabbros — that cut across the Ujaraaluk rock formation, hoping to obtain independent age constraints. The fact that these newly studied metagabbros are in intrusion in the Ujaraaluk rocks implies that the latter must be older. The project was led by masters student Chris Sole at the University of Ottawa, who joined us in the field. Back in the laboratory, we collaborated with French geochronologist Jean-Louis Paquette. Additionally, two undergraduate students — David Benn (University of Ottawa) and Joeli Plakholm (Carleton University) participated to the project. We combined our field observations with petrology, geochemistry, geochronology and applied two independent samarium-neodymium age dating methods, dating techniques used to assess the absolute ages of magmatic rocks, before these become metamorphic rocks. Both assessments yielded the same result: the intrusive rocks are 4.16 billion years old. The oldest rocks Since these metagabbros cut across the Ujaraaluk formation, the Ujaraaluk rocks must be even older, placing them firmly in the Hadean Eon. Studying the Nuvvuagittuq rocks, the only preserved rocks from the Hadean, provides a unique opportunity to learn about the earliest history of our planet. They can help us understand how the first continents formed, and how and when Earth's environment evolved to become habitable.
Time of India
01-07-2025
- Science
- Time of India
Scientists discover oldest rocks on Earth, over 4.16 billion years old
Source: The story of Earth's origins lies hidden in ancient stones, forged in a time of intense formation and volcanic activity . Recently, a groundbreaking discovery in northern Quebec has shed new light on the planet's earliest days. Scientists have confirmed the presence of the oldest known rocks on Earth in a region near the village of Inukjuak, Nunavik. This remarkable find provides a rare glimpse into the Hadean eon, a mysterious and largely unknown chapter in Earth 's history. The discovery has sparked intense scientific interest, offering new insights into the planet's formation and evolution. It brings us closer to understanding the Earth's unstable beginnings. Oldest rocks found in Northern Quebec According to a groundbreaking study published in the journal Science has revealed the discovery of the oldest known rocks on Earth in northern Quebec, offering a rare glimpse into the planet's earliest history. Collected in 2017 near the village of Inukjuak, Nunavik, these ancient rocks have sparked intense scientific interest due to their unusual properties and old composition. The research team employed advanced methods to determine the rocks' age, settling a long-standing debate that had dated the rocks to anywhere between 3.75 and 4.3 billion years old. The team's breakthrough came when they confirmed that intrusive rocks cutting through the volcanic layers were 4.16 billion years old, implying that the volcanic rocks themselves are even older. This remarkable find offers a rare glimpse into the Hadean eon, a period of Earth's history marked by intense volcanic activity and a hostile environment. How scientists accurately dated 4.16 billion-year-old rocks To determine the age of the rocks, scientists employed radiometric dating , a precise technique that measures time based on the natural decay of elements within the rocks. They focused on samarium and neodymium, elements that undergo a slow and predictable transformation, with samarium decaying into neodymium at a known rate. By analysing the current ratio of these elements, scientists can calculate when the rock originally formed. The team used two independent isotope systems, both of which yielded the same result: the rocks solidified approximately 4.16 billion years ago. This method provides an accurate and reliable way to date ancient rocks, allowing scientists to reconstruct the Earth's history. Hadean Eon made Earth a planet, but it wasn't ready for life yet The Hadean eon marked the violent and chaotic birth of Earth, around 4.6 billion years ago, with intense heat and volcanic activity. The planet was a molten rock, pummeled by space debris, and massive impacts likely shaped its formation, including the creation of the Moon. The surface was a scorching lava ocean with extreme volcanic activity, and the atmosphere consisted of toxic gases and steam. Despite these hostile conditions, Earth was setting the stage for life. As the Hadean eon came to a close around 4 billion years ago, the planet began to cool, forming a solid crust and oceans from volcanic steam and comet impacts. Ancient zircon crystals even suggest that water may have existed earlier than previously thought, slowly making the planet habitable, though devoid of life and fossils at this stage. Also read | Mice with two fathers? Scientists create fertile mice using DNA from two fathers
