The Earth-Moon system during the Late Heavy Bombardment period – geochemical support for impacts dominated by comets.
The solid planets assembled 4.57 Gyr ago during a period of less than 100 Myr, but the bulk of the impact craters we see on the inner planets formed much later, in a narrow time interval between 3.8 and 3.9 Gyr ago, during the so-called Late Heavy Bombardment (LHB). It is not certain what caused the...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.312.7222 2023-05-15T16:29:38+02:00 The Earth-Moon system during the Late Heavy Bombardment period – geochemical support for impacts dominated by comets. Uffe Gr˚ae Jørgensen Yuichi Hatsukawa Robert Frei Yosuke Toh Atsushi Kimura The Pennsylvania State University CiteSeerX Archives 907 application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.312.7222 http://arxiv.org/pdf/0907.4104v1.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.312.7222 http://arxiv.org/pdf/0907.4104v1.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://arxiv.org/pdf/0907.4104v1.pdf text ftciteseerx 2016-01-07T22:36:12Z The solid planets assembled 4.57 Gyr ago during a period of less than 100 Myr, but the bulk of the impact craters we see on the inner planets formed much later, in a narrow time interval between 3.8 and 3.9 Gyr ago, during the so-called Late Heavy Bombardment (LHB). It is not certain what caused the LHB, and it has not been well known whether the impactors were comets or asteroids, but our present study lend support to the idea that it was comets. Due to the Earth’s higher gravity, the impactors will have hit the Earth with ∼twice the energy density that they hit the Moon, and the bombardment will have continued on Earth longer than on the Moon. All solid surface of the Earth will have been completely covered with craters by the end of the LHB. However, almost nothing of the Earth’s crust from even the end of this epoch, is preserved today. One of the very few remnants, though, is exposed as the Isua greenstone belt (IGB) and nearby areas in Western Greenland. During a field expedition to Isua, we sampled three types of metasedimentary rocks, deposited ∼3.8 billion years ago, that contain information about the sedimentary river load from larger areas of surrounding land surfaces (mica-schist and turbidites) and of the contemporaneous seawater (BIF). Our samples show evidence of Text Greenland Unknown Greenland |
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The solid planets assembled 4.57 Gyr ago during a period of less than 100 Myr, but the bulk of the impact craters we see on the inner planets formed much later, in a narrow time interval between 3.8 and 3.9 Gyr ago, during the so-called Late Heavy Bombardment (LHB). It is not certain what caused the LHB, and it has not been well known whether the impactors were comets or asteroids, but our present study lend support to the idea that it was comets. Due to the Earth’s higher gravity, the impactors will have hit the Earth with ∼twice the energy density that they hit the Moon, and the bombardment will have continued on Earth longer than on the Moon. All solid surface of the Earth will have been completely covered with craters by the end of the LHB. However, almost nothing of the Earth’s crust from even the end of this epoch, is preserved today. One of the very few remnants, though, is exposed as the Isua greenstone belt (IGB) and nearby areas in Western Greenland. During a field expedition to Isua, we sampled three types of metasedimentary rocks, deposited ∼3.8 billion years ago, that contain information about the sedimentary river load from larger areas of surrounding land surfaces (mica-schist and turbidites) and of the contemporaneous seawater (BIF). Our samples show evidence of |
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The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Uffe Gr˚ae Jørgensen Yuichi Hatsukawa Robert Frei Yosuke Toh Atsushi Kimura |
spellingShingle |
Uffe Gr˚ae Jørgensen Yuichi Hatsukawa Robert Frei Yosuke Toh Atsushi Kimura The Earth-Moon system during the Late Heavy Bombardment period – geochemical support for impacts dominated by comets. |
author_facet |
Uffe Gr˚ae Jørgensen Yuichi Hatsukawa Robert Frei Yosuke Toh Atsushi Kimura |
author_sort |
Uffe Gr˚ae Jørgensen |
title |
The Earth-Moon system during the Late Heavy Bombardment period – geochemical support for impacts dominated by comets. |
title_short |
The Earth-Moon system during the Late Heavy Bombardment period – geochemical support for impacts dominated by comets. |
title_full |
The Earth-Moon system during the Late Heavy Bombardment period – geochemical support for impacts dominated by comets. |
title_fullStr |
The Earth-Moon system during the Late Heavy Bombardment period – geochemical support for impacts dominated by comets. |
title_full_unstemmed |
The Earth-Moon system during the Late Heavy Bombardment period – geochemical support for impacts dominated by comets. |
title_sort |
earth-moon system during the late heavy bombardment period – geochemical support for impacts dominated by comets. |
publishDate |
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url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.312.7222 http://arxiv.org/pdf/0907.4104v1.pdf |
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Greenland |
geographic_facet |
Greenland |
genre |
Greenland |
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Greenland |
op_source |
http://arxiv.org/pdf/0907.4104v1.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.312.7222 http://arxiv.org/pdf/0907.4104v1.pdf |
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Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
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1766019347435749376 |