<P> The oldest dated rocks on Earth , as an aggregate of minerals that have not been subsequently broken down by erosion or melted , are more than 4 billion years old , formed during the Hadean Eon of Earth 's geological history . Such rocks are exposed on the Earth 's surface in very few places . Some of the oldest surface rock can be found in the Canadian Shield , Australia , Africa and in a few other old regions around the world . The ages of these felsic rocks are generally between 2.5 and 3.8 billion years . The approximate ages have a margin of error of millions of years . In 1999 , the oldest known rock on Earth was dated to 4.031 ± 0.003 billion years , and is part of the Acasta Gneiss of the Slave craton in northwestern Canada . Researchers at McGill University found a rock with a very old model age for extraction from the mantle ( 3.8 to 4.28 billion years ago ) in the Nuvvuagittuq greenstone belt on the coast of Hudson Bay , in northern Quebec ; the true age of these samples is still under debate , and they may actually be closer to 3.8 billion years old . Older than these rocks are crystals of the mineral zircon , which can survive the disaggregation of their parent rock and be found and dated in younger rock formations . </P>
<P> The oldest dated rocks on Earth , as an aggregate of minerals that have not been subsequently broken down by erosion or melted , are more than 4 billion years old , formed during the Hadean Eon of Earth 's geological history . Such rocks are exposed on the Earth 's surface in very few places . Some of the oldest surface rock can be found in the Canadian Shield , Australia , Africa and in a few other old regions around the world . The ages of these felsic rocks are generally between 2.5 and 3.8 billion years . The approximate ages have a margin of error of millions of years . In 1999 , the oldest known rock on Earth was dated to 4.031 ± 0.003 billion years , and is part of the Acasta Gneiss of the Slave craton in northwestern Canada . Researchers at McGill University found a rock with a very old model age for extraction from the mantle ( 3.8 to 4.28 billion years ago ) in the Nuvvuagittuq greenstone belt on the coast of Hudson Bay , in northern Quebec ; the true age of these samples is still under debate , and they may actually be closer to 3.8 billion years old . Older than these rocks are crystals of the mineral zircon , which can survive the disaggregation of their parent rock and be found and dated in younger rock formations . </P>
of what type are the oldest surviving rocks on earth
of what type are the oldest surviving rocks on earth
felsic
felsic