منابع مشابه
Tectonics of early Earth: Some geodynamic considerations
Today, plate tectonics is the dominant tectonic style on Earth, but in a hotter Earth tectonics may have looked different due to the presence of more melting and associated compositional buoyancy as well as the presence of a weaker mantle and lithosphere. Here we review the geodynamic constraints on plate tectonics and proposed alternatives throughout Earth’s history. Observations suggest a 100...
متن کاملPlate tectonics on early Earth? Weighing the paleomagnetic evidence
Paleomagnetism is the only quantitative method available to test for lateral motions by tectonic plates across the surface of ancient Earth. Here, we present several analyses of such motions using strict quality criteria from the global paleomagnetic database of pre–800 Ma rocks. Extensive surface motion of cratons can be documented confi dently to older than ca. 2775 Ma, but considering only t...
متن کاملUsing the Moon to explore early solar system bombardment
A decade-long campaign to test the lunar cataclysm hypothesis continues to support an intense period of bombardment several hundred million years after solar system formation. Geological, geochemical, and isotopic data imply that (i) basin-forming impacts occurred on the Moon ∼4 Ga and (ii) impacts occurred on asteroids ∼3.6–4.1 Ga, implying the lunar cataclysm is actually an inner solar system...
متن کاملThe Early Bombardment History of Mars Revealed in Ancient Megabasins
Minton, W. F. Bottke, H. V. Frey, R. J. Lillis, J. H. Roberts, S. T. Stewart Purdue University, Dept. of Earth & Atm. Sci., 550 Stadium Mall Dr., West Lafayette, IN 47907, [email protected], Southwest Research Institute and NASA Lunar Science Institute, 1050 Walnut St. Ste. 300, Boulder, CO 80302, Geodynamics Branch, Goddard Flight Center, Greenbelt, MD 20771, University of California, Berkel...
متن کاملCharon tectonics
New Horizons images of Pluto's companion Charon show a variety of terrains that display extensional tectonic features, with relief surprising for this relatively small world. These features suggest a global extensional areal strain of order 1% early in Charon's history. Such extension is consistent with the presence of an ancient global ocean, now frozen.
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ژورنال
عنوان ژورنال: Science
سال: 2017
ISSN: 0036-8075,1095-9203
DOI: 10.1126/science.358.6365.883-g