An unusual concentration of impact craters suggests that they may have been caused by the breakup of an asteroid that created a temporary debris ring around Earth.
Ordovician
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What Conditions Accompanied the Late Ordovician Mass Extinction?
The second-largest mass extinction in Earth’s history took place in a period of stresses from non-sulfidic anoxia in shelf areas, together with glacioeustatic sea-level change and climatic cooling.
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Geologists Have a New Tool for Reconstructing the Ancient Climate
A new study of seafloor sediments finds that the temperature record in the early Paleozoic corresponds to significant shifts in the diversity of life on Earth.
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Earth’s Eccentric Orbit Helped Preserve Rare Soft-Tissue Fossils
Cyclical changes in Earth’s orbit helped to preserve rare fossils in Morocco.
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Tiny Algae May Have Prompted a Mass Extinction
Dead algae sinking to the ocean floor may have sequestered carbon 445 million years ago, triggering the glaciation that accompanied the Late Ordovician mass extinction.
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A Volcanic Trigger for Earth’s First Mass Extinction?
Abnormally high levels of mercury in Ordovician rocks may imply that a huge surge of volcanism took place at a time when much of the planet’s ocean life vanished.