Articles tagged with Geochronology
Researchers at the University of Texas at Austin have redated a meteor impact site in Oklahoma, shifting its age from 467.5 million years ago to 370 million years ago. This discovery has significant implications for understanding ancient life and mass extinctions.
A new study recalibrates the argon-argon dating method, allowing for highly precise and accurate dating of volcanic eruptions. This improvement enables geologists to attach accurate dates to geologic events, including past eruptions of volcanoes that threaten urban areas, and helps ground-truth other dating methods.
Researchers discovered that prehistoric builders deliberately transported enormous 25-tonne stones from Brimham Rocks 18km away to build Britain's tallest stone row, the Devil's Arrows. The study challenges long-held assumptions about ancient monument construction and highlights the importance of landscape and shared belief systems.
Scientists propose a colossal cliff across ancient North America may have exposed Grand Canyon's oldest rocks nearly a billion years before it was carved by the Colorado River. The study suggests the 'great escarpment' of steep rocky cliffs formed when the supercontinent Rodinia broke apart 800 million years ago.
Researchers from Heidelberg University and international partners used (U-Th)/He dating to establish consistent age models for several maars in the West Eifel. The analysis reveals that many volcanic eruptions occurred in short pulses, with three episodes occurring approximately 75,000, 48,000, and 25,000 years ago.
Researchers developed a new tool to track ancient climate from wetland sediments, revealing turbulent environmental past in the Mediterranean. People adapted creatively, developing new technologies and strategies, such as floodwater farming and herd animal management.
Researchers used a novel technique to analyze millions of individual particles in Antarctic ice cores, revealing common dust sources during the last Ice Age. The study highlights the importance of atmospheric circulation changes and provides insights into ancient climate systems and potential future environmental shifts.
A team of scientists discovered the King's Trough Complex, a colossal submarine canyon off Portugal's coast, formed by tectonic processes and hot mantle material. The structure extends over 500 kilometers, with Peake Deep as one of the deepest points in the Atlantic Ocean.
Researchers from the University of Göttingen have identified oxygen isotopes in 'cherts' as indicators of heat flow on early Earth. The study reveals that cherts record paleo-heat flow on the Shatsky Rise oceanic plateau, providing insights into the conditions on the Earth's surface up to 3.5 billion years ago.
A large region of unusually hot rock deep beneath the Appalachian Mountains in the United States could be linked to Greenland and North America splitting apart 80 million years ago. The 'mantle wave' theory suggests that hot, dense rock slowly peels away from the base of tectonic plates after continents break apart.
An international team of researchers proposes that a meteorite impact just west of Winslow, Arizona, created Meteor Crater and triggered a massive landslide in the Grand Canyon. The study found evidence of a paleolake forming at the same time, with driftwood dating back to around 55,000 years.
A nearly complete fossil of Westlothiana lizziae, a four-legged creature, has been dated to 346 million years ago, shedding new light on the evolution of amphibians, birds, reptiles, and mammals. This age places the specimens in Romer's Gap, a pivotal time period where water-dwelling fish transitioned to land animals.
A 1,200-tonne boulder in Tonga is one of the largest known wave-transported rocks, providing new insights into past tsunamis. Numerical modelling suggests tsunami heights of 50m lasting 90 seconds dislodged the boulder from its cliff-edge origin.
Researchers found that Earth's first crust, formed 4.5 billion years ago, likely had chemical features similar to modern continental crust, rewriting the geological timeline. This suggests the distinctive chemical signature of continents was established at the beginning of Earth's history.
A research team from the University of Göttingen investigated the influence of the Zagros Mountains on Earth's surface bending. They found that the Neotethys oceanic plate is breaking off horizontally, creating a depression in the region.
A new study confirms that the center of Greenland's ice sheet melted away in recent geological past, exposing a green, tundra landscape. The discovery suggests that the giant ice sheet is more fragile than previously thought and increases the risk of sea-level rise, potentially leading to catastrophic flooding in coastal cities.
Scientists developed a reliable proxy to reconstruct ancient marine oxygen levels, revealing a significant rise during the Late Paleozoic era. This finding suggests early animals evolved in oxygen-poor oceans, providing critical context for studying exoplanet atmospheres.
The Lunar Environment Monitoring System, developed by UMD researchers, will track seismic activity on the moon's surface during the upcoming Artemis III mission. The system's data will help prepare NASA for a long-term presence on other planetary bodies.
A team of geologists from the University of Colorado Boulder has made a breakthrough in understanding the emergence of the Spanish Peaks. The study reveals that the peaks first formed around 24 million years ago when magma welled up from deep within Earth's crust, but didn't break through to the surface until about 17 million years ago.
New evidence reveals that giant ape species 'Gigantopithcus blacki' went extinct between 295,000 and 215,000 years ago due to its inability to adapt to changing climates and food preferences. The study used multiple dating techniques and environmental analysis to confirm the extinction timeline.
Researchers analyzed whiteschist from the Dora Maira Massif to study rapid upward movements, revealing a sharp decrease in pressure or decompression. This suggests that UHP rocks may not have reached a depth of 120 kilometers before returning to the surface.
A team of experts analyzed ancient diamonds formed between 650 and 450 million years ago, providing new processes for how continents evolved and moved. The research sheds light on the supercontinent cycle and offers a direct window into Earth's deep workings.
Geologists found evidence of subduction at continental margins during periods of continental flooding, which raised sea levels. The study suggests that subduction under Gondwana may have caused the Sauk Transgression, a major flood event in North America's geologic record.
A groundbreaking study finds that microbial life can exist without plate tectonics, challenging a fundamental theory of geology. Zircon crystals from the Barberton Greenstone Belt reveal a stagnant lid regime on ancient Earth, leading to continent formation and potentially habitable conditions.
A team of researchers from UNLV has named a previously unexplored 500 million-year-old Grand Canyon formation, the Frenchman Mountain Dolostone. The new formation was identified through scientific detective work and is now understood to have been deposited over an interval of 7.3 million years during the Cambrian Period.
Researchers from UC Berkeley used rock analysis to determine that the valley's impressive depth was formed since 10 million years ago, with most of it carved in the past 5 million years. The study employed a novel technique called helium-4/helium-3 thermochronometry to reconstruct the temperature history of the rocks.
The Perseverance rover collected igneous cumulate rocks from four sites on the floor of Jezero Crater, providing evidence of aqueous alteration. These rocks will help scientists determine when Mars' climate was conducive to lakes and rivers, addressing major questions about the planet's history.
Researchers analyzed fossil corals to reveal changed ocean current circulation patterns. The data supports a scenario where the upper Pacific Ocean was more mixed during the last ice age, contributing to carbon storage and cooler climates.
Researchers from Vrije Universiteit Brussel used new techniques to determine the age of limestone layers and fossils in Maastricht quarries, dating back to the last dinosaur age. The study found that the shallow sea was rich in oxygen, suitable for sustaining a diverse ecosystem.
Researchers have proposed new radioisotopic dates for Ediacaran fossil assemblages and carbon isotope perturbations, providing age constraints for both. The study reveals two negative carbon isotope excursions in the 575–550 Ma period, with the Shuram event occurring between 575 Ma and 565 Ma.
The high flux neutron generator produces boutique neutrons ideal for dating fine-grained rocks and analyzing evidence. The device expands the capability of dating materials like clay minerals associated with ore deposits.
The new center aims to restore temperature regimes in sedimentary basins using geochronology and thermochronology. This approach is expected to be effective and economical for companies searching for petroleum.
A team of researchers has found that the magma body at Long Valley was much cooler before the eruption than previously thought. The discovery challenges the traditional view of a long period with a big tank of molten rock in the crust, instead suggesting that magma is stored for a short period in a cool, crystalline state.
Dr. Rodney Ewing has made significant contributions to the field of geoscience, bridging disciplines to develop new applications and advancing science through publications. He serves on various advisory committees and policy boards, providing timely leadership in the disposal of high-level radioactive waste.
Researchers in China, Egypt, Israel, Argentina, Mexico and California published new findings on sedimentology, petrology and paleotopography. The studies reveal insights into the geological processes that shape these regions, including eolian sand fractionation, magmatic activity, and exhumation of the Andes.
A team of scientists proposes a new system for classifying units of the Geological Time Scale, resolving the debate between single-time and dual-time hierarchies. The proposed realignment maintains both parallel sets of units, allowing for flexibility in choosing one or the other as needed.
Studies explore Ligurian accretionary complex evolution and Andean thrusting, shedding light on continental margin dynamics. Cosmogenic isotope analysis reveals insights into the geological history of Wonderwerk Cave and Redoubt Volcano.
Eric J. Essene, George E. Gehrels, and Dana L. Royer received the Penrose, Day, and Donath Medals for their groundbreaking research in metamorphic petrology, U-Th-Pb geochronology, and paleoclimatology.
Researchers at the University of California, Berkeley, have improved the argon-argon dating method to provide more precise absolute dates for geologic events, including the Cretaceous-Tertiary boundary and dinosaur extinction. The new date is 65.95 million years ago, with an uncertainty of 40,000 years.
A team of geologists and anthropologists reevaluated the alleged 40,000-year-old human footprints in Mexico, determining a new age of around 1.3 million years using argon/argon dating technique. This revised date challenges the accepted theory that humans arrived in the Americas at 11,000 years ago, sparking debate among researchers.
Researchers at Texas A&M University and the Berkeley Geochronology Center date ancient rocks containing 'footprints' to 1.3 million years old, suggesting an earlier human migration than previously believed. The findings contradict claims of 40,000-year-old footprints in England.