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Categories: Geoscience: Geology, Paleontology: Climate

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Sapphires are among the most precious gems, yet they consist solely of chemically 'contaminated' aluminum oxide, or corundum. It is widely assumed that these crystals with their characteristically blue color come from deep crustal rocks and accidentally ended up on the Earth's surface as magma ascended. Geoscientists have now been able to show that the sapphire grains found in the Eifel (Germany) formed in association with volcanism.

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A new study finds disproportionate effects of temperature shifts on an icy glacier layer.

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A new analysis of rocks thought to be at least 2.5 billion years old helps clarify the chemical history of Earth's mantle -- the geologic layer beneath the planet's crust. The findings hone scientists' understanding of Earth's earliest geologic processes, and they provide new evidence in a decades-long scientific debate about the geologic history of Earth. Specifically, the results provide evidence that the oxidation state of the vast majority of Earth's mantle has remained stable through geologic time and has not undergone major transitions, contrary to what has been suggested previously by other researchers.

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Fluids circulating underground change rocks over the course of time. These processes must be taken into account if they are to be used as a climate archive. Researchers have used 380-million-year-old limestones from Hagen-Hohenlimburg to show in detail which climate information is still preserved in the rock.

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New research has examined the fossil record going back 66 million years and tracked changes to mammalian ecosystems and species diversity on the North American continent.

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As the planet continues to warm due to human-driven climate change, accurate computer climate models will be key in helping illuminate exactly how the climate will continue to be altered in the years ahead.

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A recent study provides new insights into ancient cultures in Canada's Arctic, focusing on Paleo-Inuit and Thule-Inuit peoples over thousands of years. Researchers detected human presence and settlements on Somerset Island, Nunavut, by analyzing sediment samples.

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Age data for certain classes of meteorite have made it possible to gain new findings on the origin of small water-rich astronomical bodies in the early solar system. These planetesimals continually supplied building materials for planets -- also for the Earth, whose original material contained little water. The Earth received its actual water through planetesimals, which emerged at low temperatures in the outer solar system, as shown by computational models carried out by an international research teach with participation by earth scientists.

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In recent years global warming has left its mark on the Antarctic ice sheets. The 'eternal' ice in Antarctica is melting faster than previously assumed, particularly in West Antarctica more than East Antarctica. The root for this could lie in its formation, as an international research team has now discovered: sediment samples from drill cores combined with complex climate and ice-sheet modelling show that permanent glaciation of Antarctica began around 34 million years ago -- but did not encompass the entire continent as previously assumed, but rather was confined to the eastern region of the continent (East Antarctica).

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Global warming as well as recent droughts and floods threaten large populations along the Nile Valley. Sediment cores off the Nile mouth reveal insights into the effects and causes of heavy rainfall episodes about 9,000 years ago. That will help to prepare for weather extremes in a changing climate.

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Two samples from Mars together deliver clear evidence of the origin of Martian organic material. The study presents solid evidence for a prediction made over a decade ago that could be key to understanding how organic molecules, the foundation of life, were first formed here on Earth.

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Human hunting, not climate change, played a decisive role in the extinction of large mammals over the last 50,000 years. This conclusion comes from researchers who reviewed over 300 scientific articles from many different fields of research.

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Hydrothermal vents can be found around the world at the junctions of drifting tectonic plates. But there are many hydrothermal fields still to be discovered. During a 2022 expedition of the MARIA S. MERIAN, the first field of hydrothermal vents on the 500-kilometer-long Knipovich Ridge off the coast of Svalbard was discovered.

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Why did multicellularity arise? Solving that mystery may help pinpoint life on other planets and explain the vast diversity and complexity seen on Earth today, from sea sponges to redwoods to human society. A new article shows how specific physical conditions -- especially ocean viscosity and resource deprivation -- during the global glaciation period known as Snowball Earth could have driven eukaryotes to turn multicellular.

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Researchers have found a chemical clue in Italian limestone that explains a mass extinction of marine life in the Early Jurassic period, 183 million years ago. Volcanic activity pumped out CO2, warming oceans and lowering their oxygen levels. The findings may foretell the impact climate change and oxygen depletion might have on today's oceans.

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Researchers continue to expand the case for the Younger Dryas Impact hypothesis. The idea proposes that a fragmented comet smashed into the Earth's atmosphere 12,800 years ago, causing a widespread climatic shift that, among other things, led to the abrupt reversal of the Earth's warming trend and into an anomalous near-glacial period called the Younger Dryas.

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Scientists predict from geochemical data that Iceland is entering a new volcanic era that will last for decades, possibly centuries. Under an hour's drive from the country's capital city, the ongoing eruptions pose considerable risks for economic disruption, and they leave evacuated communities uncertain of a possible return.

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A doubling of the amount of CO2 in the atmosphere could cause an increase in the average temperature on earth from 7 to even a maximum of 14 degrees. That is shown in the analysis of sediments from the Pacific Ocean off the coast of California.

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The new study provides unambiguous evidence that the inner core began to decrease its speed around 2010, moving slower than the Earth's surface.

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When it comes to the ocean's response to global warming, we're not in entirely uncharted waters. A new study shows that episodes of extreme heat in Earth's past caused the exchange of waters from the surface to the deep ocean to decline.