Earth Age
- Thread starter yudansha
- Start date
Patriciaqsagie
Patricia
Age of the Earth
The generally accepted age forthe Earth is about 4.55 billion years.The oldest rocks wich have been found sa far ont the Earth date to about 3.8 to 3.9 billion yaers ago. Some of this rocks are sedimentary,, and include minerals which are themsleves as ols 4.1 to 4.2 billion years. Rocks of this age are relatively rare, however rocks that are at least 3.5 billion years in age have been found on Noth America, Greenland, Australia, Africa and Asia.
While these values do not compute an age for the Earth, they do establish a lower limit (the Earth must be at least as old as any formation on it). This llower limit is at least concordate with the independently derived of 5.55 billion years for the Earth's actual age.
Patricia
The generally accepted age forthe Earth is about 4.55 billion years.The oldest rocks wich have been found sa far ont the Earth date to about 3.8 to 3.9 billion yaers ago. Some of this rocks are sedimentary,, and include minerals which are themsleves as ols 4.1 to 4.2 billion years. Rocks of this age are relatively rare, however rocks that are at least 3.5 billion years in age have been found on Noth America, Greenland, Australia, Africa and Asia.
While these values do not compute an age for the Earth, they do establish a lower limit (the Earth must be at least as old as any formation on it). This llower limit is at least concordate with the independently derived of 5.55 billion years for the Earth's actual age.
Patricia
I honestly have no idea. This is the U.S. Government's slant. I'm interested in yours, Yudansha. Interesting that they say northwest Canada has the oldest rocks on earth, with northern Michigan not far behind.
AGE OF THE EARTH
So far scientists have not found a way to determine the exact age of the Earth directly from Earth rocks because Earth's oldest rocks have been recycled and destroyed by the process of plate tectonics. If there are any of Earth's primordial rocks left in their original state, they have not yet been found. Nevertheless, scientists have been able to determine the probable age of the Solar System and to calculate an age for the Earth by assuming that the Earth and the rest of the solid bodies in the Solar System formed at the same time and are, therefore, of the same age.
The ages of Earth and Moon rocks and of meteorites are measured by the decay of long-lived radioactive isotopes of elements that occur naturally in rocks and minerals and that decay with half lives of 700 million to more than 100 billion years to stable isotopes of other elements. These dating techniques, which are firmly grounded in physics and are known collectively as radiometric dating, are used to measure the last time that the rock being dated was either melted or disturbed sufficiently to rehomogenize its radioactive elements.
Ancient rocks exceeding 3.5 billion years in age are found on all of Earth's continents. The oldest rocks on Earth found so far are the Acasta Gneisses in northwestern Canada near Great Slave Lake (4.03 Ga) and the Isua Supracrustal rocks in West Greenland (3.7 to 3.8 Ga), but well-studied rocks nearly as old are also found in the Minnesota River Valley and northern Michigan (3.5-3.7 billion years), in Swaziland (3.4-3.5 billion years), and in Western Australia (3.4-3.6 billion years). [See Editor's Note.] These ancient rocks have been dated by a number of radiometric dating methods and the consistency of the results give scientists confidence that the ages are correct to within a few percent. An interesting feature of these ancient rocks is that they are not from any sort of "primordial crust" but are lava flows and sediments deposited in shallow water, an indication that Earth history began well before these rocks were deposited. In Western Australia, single zircon crystals found in younger sedimentary rocks have radiometric ages of as much as 4.3 billion years, making these tiny crystals the oldest materials to be found on Earth so far. The source rocks for these zircon crystals have not yet been found. The ages measured for Earth's oldest rocks and oldest crystals show that the Earth is at least 4.3 billion years in age but do not reveal the exact age of Earth's formation.
The best age for the Earth (4.54 Ga) is based on old, presumed single-stage leads coupled with the Pb ratios in troilite from iron meteorites, specifically the Canyon Diablo meteorite. In addition, mineral grains (zircon) with U-Pb ages of 4.4 Ga have recently been reported from sedimentary rocks in west-central Australia.
The Moon is a more primitive planet than Earth because it has not been disturbed by plate tectonics; thus, some of its more ancient rocks are more plentiful. Only a small number of rocks were returned to Earth by the six Apollo and three Luna missions. These rocks vary greatly in age, a reflection of their different ages of formation and their subsequent histories. The oldest dated moon rocks, however, have ages between 4.4 and 4.5 billion years and provide a minimum age for the formation of our nearest planetary neighbor.
Thousands of meteorites, which are fragments of asteroids that fall to Earth, have been recovered. These primitive objects provide the best ages for the time of formation of the Solar System. There are more than 70 meteorites, of different types, whose ages have been measured using radiometric dating techniques. The results show that the meteorites, and therefore the Solar System, formed between 4.53 and 4.58 billion years ago. The best age for the Earth comes not from dating individual rocks but by considering the Earth and meteorites as part of the same evolving system in which the isotopic composition of lead, specifically the ratio of lead-207 to lead-206 changes over time owing to the decay of radioactive uranium-235 and uranium-238, respectively. Scientists have used this approach to determine the time required for the isotopes in the Earth's oldest lead ores, of which there are only a few, to evolve from its primordial composition, as measured in uranium-free phases of iron meteorites, to its compositions at the time these lead ores separated from their mantle reservoirs. These calculations result in an age for the Earth and meteorites, and hence the Solar System, of 4.54 billion years with an uncertainty of less than 1 percent. To be precise, this age represents the last time that lead isotopes were homogeneous througout the inner Solar System and the time that lead and uranium was incorporated into the solid bodies of the Solar System.
The age of 4.54 billion years found for the Solar System and Earth is consistent with current calculations of 11 to 13 billion years for the age of the Milky Way Galaxy (based on the stage of evolution of globular cluster stars) and the age of 10 to 15 billion years for the age of the Universe (based on the recession of distant galaxies).
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I thought this was pretty interesting.
AGE OF THE EARTH
So far scientists have not found a way to determine the exact age of the Earth directly from Earth rocks because Earth's oldest rocks have been recycled and destroyed by the process of plate tectonics. If there are any of Earth's primordial rocks left in their original state, they have not yet been found. Nevertheless, scientists have been able to determine the probable age of the Solar System and to calculate an age for the Earth by assuming that the Earth and the rest of the solid bodies in the Solar System formed at the same time and are, therefore, of the same age.
The ages of Earth and Moon rocks and of meteorites are measured by the decay of long-lived radioactive isotopes of elements that occur naturally in rocks and minerals and that decay with half lives of 700 million to more than 100 billion years to stable isotopes of other elements. These dating techniques, which are firmly grounded in physics and are known collectively as radiometric dating, are used to measure the last time that the rock being dated was either melted or disturbed sufficiently to rehomogenize its radioactive elements.
Ancient rocks exceeding 3.5 billion years in age are found on all of Earth's continents. The oldest rocks on Earth found so far are the Acasta Gneisses in northwestern Canada near Great Slave Lake (4.03 Ga) and the Isua Supracrustal rocks in West Greenland (3.7 to 3.8 Ga), but well-studied rocks nearly as old are also found in the Minnesota River Valley and northern Michigan (3.5-3.7 billion years), in Swaziland (3.4-3.5 billion years), and in Western Australia (3.4-3.6 billion years). [See Editor's Note.] These ancient rocks have been dated by a number of radiometric dating methods and the consistency of the results give scientists confidence that the ages are correct to within a few percent. An interesting feature of these ancient rocks is that they are not from any sort of "primordial crust" but are lava flows and sediments deposited in shallow water, an indication that Earth history began well before these rocks were deposited. In Western Australia, single zircon crystals found in younger sedimentary rocks have radiometric ages of as much as 4.3 billion years, making these tiny crystals the oldest materials to be found on Earth so far. The source rocks for these zircon crystals have not yet been found. The ages measured for Earth's oldest rocks and oldest crystals show that the Earth is at least 4.3 billion years in age but do not reveal the exact age of Earth's formation.
The best age for the Earth (4.54 Ga) is based on old, presumed single-stage leads coupled with the Pb ratios in troilite from iron meteorites, specifically the Canyon Diablo meteorite. In addition, mineral grains (zircon) with U-Pb ages of 4.4 Ga have recently been reported from sedimentary rocks in west-central Australia.
The Moon is a more primitive planet than Earth because it has not been disturbed by plate tectonics; thus, some of its more ancient rocks are more plentiful. Only a small number of rocks were returned to Earth by the six Apollo and three Luna missions. These rocks vary greatly in age, a reflection of their different ages of formation and their subsequent histories. The oldest dated moon rocks, however, have ages between 4.4 and 4.5 billion years and provide a minimum age for the formation of our nearest planetary neighbor.
Thousands of meteorites, which are fragments of asteroids that fall to Earth, have been recovered. These primitive objects provide the best ages for the time of formation of the Solar System. There are more than 70 meteorites, of different types, whose ages have been measured using radiometric dating techniques. The results show that the meteorites, and therefore the Solar System, formed between 4.53 and 4.58 billion years ago. The best age for the Earth comes not from dating individual rocks but by considering the Earth and meteorites as part of the same evolving system in which the isotopic composition of lead, specifically the ratio of lead-207 to lead-206 changes over time owing to the decay of radioactive uranium-235 and uranium-238, respectively. Scientists have used this approach to determine the time required for the isotopes in the Earth's oldest lead ores, of which there are only a few, to evolve from its primordial composition, as measured in uranium-free phases of iron meteorites, to its compositions at the time these lead ores separated from their mantle reservoirs. These calculations result in an age for the Earth and meteorites, and hence the Solar System, of 4.54 billion years with an uncertainty of less than 1 percent. To be precise, this age represents the last time that lead isotopes were homogeneous througout the inner Solar System and the time that lead and uranium was incorporated into the solid bodies of the Solar System.
The age of 4.54 billion years found for the Solar System and Earth is consistent with current calculations of 11 to 13 billion years for the age of the Milky Way Galaxy (based on the stage of evolution of globular cluster stars) and the age of 10 to 15 billion years for the age of the Universe (based on the recession of distant galaxies).
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I thought this was pretty interesting.
yudansha
TheGreatOne
No religious arguments? Surprise, surprise! Universe & aging:
So, it's interesting how nobody put their religious perspective on the age of Earth.
Thanks Patricia and welcome (it can be fun here if you participate); and thanks Serena for contributing. All that information on rock dating I've already known, heard, read, being lectured on, being tested ...
It's just funny how there are so many creationist believers here who rejected the theory of evolution, said that they will only believe one thing and one thing only about the origins of life, yet none wanted to refute some of these posts (either its lack of knowledge or just not enough time to respond as there've been only 15 or so replies).
Trinity: "I wonder though, considering the time difference in space and our time on earth,how old all is according to time in space.Did that make sense?"
Yes, it made sense (I don't know, but if you're a creationist believer, you wouldn't believe such a thing, since the time dilation is a theory proposed and proven by Albert Einstein ... where everything in physics was based upon the Big Bang theory - contradicting creationism, as Earth evolved much later).
But did you mean how old the universe was? The current data that astronomers and astrophysicists compiled, suggests that the universe is approximately 13.7 billion years old; whereas Earth is 4.6byo.
So, it's interesting how nobody put their religious perspective on the age of Earth.
Thanks Patricia and welcome (it can be fun here if you participate); and thanks Serena for contributing. All that information on rock dating I've already known, heard, read, being lectured on, being tested ...
It's just funny how there are so many creationist believers here who rejected the theory of evolution, said that they will only believe one thing and one thing only about the origins of life, yet none wanted to refute some of these posts (either its lack of knowledge or just not enough time to respond as there've been only 15 or so replies).
Trinity: "I wonder though, considering the time difference in space and our time on earth,how old all is according to time in space.Did that make sense?"
Yes, it made sense (I don't know, but if you're a creationist believer, you wouldn't believe such a thing, since the time dilation is a theory proposed and proven by Albert Einstein ... where everything in physics was based upon the Big Bang theory - contradicting creationism, as Earth evolved much later).
But did you mean how old the universe was? The current data that astronomers and astrophysicists compiled, suggests that the universe is approximately 13.7 billion years old; whereas Earth is 4.6byo.
Trinity
My Hero.
Well I'm about to put my caboos on a limb here but, I do believe we have a creator but, I also believe we are living in A diminsion that can is travled by those further advanced then we are and it has been being travled for thousands of years!I think I'll leave it there for now.....
Patriciaqsagie
Patricia
Trinity
My Hero.
No that didn't come to mind!LOL I do however feel that we are going to be very surprised at what is and what we have not been told as far as what science knows now.It dosn't take a rocket scientist to go back two thousand years and wonder why these people drew space ships on paintings and cave walls.LOL