Articles tagged with Continental Crust
Researchers have identified a field of tektites in Brazilian territory, which may have been formed by a single cosmic collision event. The geraisites, named after the Brazilian state of Minas Gerais where they were first discovered, have distinct geochemical signatures and date back approximately 6.3 million years.
A new theory suggests that water accumulated in the mantle caused an overturn, supplying materials for continent formation and strengthening the geodynamo. This event accelerated core cooling, correlating with high paleointensities in Archean rocks.
Tulane researchers discovered that an area of the African tectonic plate, previously thought to be weak, is now resisting deformation due to dehydration 80 million years ago. This process strengthened the plate and made it more resistant to future breakup.
A recent study from the University of Copenhagen found that the oldest Scandinavian bedrock originated in Greenland approximately 3.75 billion years ago. The discovery provides new insights into the formation of continents and the emergence of life on Earth, highlighting the importance of fixed continents for supporting life.
Scientists have identified a new mechanism for forming the building blocks of Earth's early crust, which led to the creation of modern continents. The discovery relies solely on internal geological forces and challenges the long-standing theory of Archean TTG magmatism being linked to the start of plate tectonics.
Researchers found that stable cratons have repeatedly deformed beneath their crust since formation, contradicting decades of plate tectonics theory. This deformation is caused by dense mantle keels peeling away from the lithosphere during supercontinent breakup.
A study from Smithsonian researchers deepens understanding of Earth's crust by testing and eliminating the garnet hypothesis about why continental crust is lower in iron and more oxidized. The findings suggest that intense heat and pressure cannot produce the necessary conditions for garnet formation, contradicting a popular explanation.
Research at KAUST demonstrates that most of the Red Sea is underlain by oceanic crust, overturning the assumption that it's an extended rift basin. The team mapped the transition from a rift to seafloor spreading and found approximately two-thirds of the Red Sea is currently covered by oceanic crust.
Researchers investigate the emergence of aerobic life through halogen ratios in crustal fluids, revealing insights into ancient environments. A newly discovered submarine volcano near Tokyo Bay, Japan, is found to have past eruptive activity that poses future hazards.
Researchers propose new dynamic model suggesting thermal energy causes continental plates to drift, but the main driving force is supplied by a gravitational slip of the continental crust and hot mantle upwelling. This model explains why the opening of the Atlantic Ocean is wider in the south than in the middle.
A team of researchers used advanced dating techniques to determine that the subduction of continental material occurred after the obduction of the Samail Ophiolite, contradicting previous estimates. The study provides new insights into subduction zones and their formation.
Scientists have discovered that weathering of continental rock began about 3.7 billion years ago, significantly earlier than previously estimated. This finding has crucial implications for plate tectonics and biological evolution, shedding new light on the early Earth's environment.
Researchers found layering consistent with volcanic activity on Venus' oldest terrain, tesserae, dating back 750 million years. This finding suggests that these regions were formed through volcanic activity rather than tectonic deformation or continental crust formation.
Researchers study syenite intrusion in Kerguelen plateau, finding similarities to continental crust formations; discovery challenges conventional understanding of continent creation
A new study published in Geology proposes that Zealandia's topographic upheaval may be linked to the formation of the western Pacific's infamous Ring of Fire. Fossils from recent seafloor drilling indicate dramatic elevation changes between 50-35 million years ago, coinciding with a global reorganization of tectonic plates.
Scientists propose that Earth's continental crust may have been thicker and present as far back as four billion years, with continents possibly rising from the sea much earlier than previously thought. The new model suggests that the survival of early crust was dependent on radioactivity levels.
A geosciences professor at the University of Akron has received a $512,045 NSF CAREER grant to investigate how lower crust strength anisotropy affects aftershock earthquake events. The study aims to provide new insights into rock properties and seismic release during earthquakes.
Researchers from MSU found evidence of CO<sub>2</sub>-rich fluids in graphite samples and fluid inclusions in quartz, suggesting the rocks formed through interaction with the Kaapvaal Craton. This discovery provides insights into the geological history of the Limpopo Complex and its potential for ore prospecting.
Researchers found evidence that the Earth's continental crust could have formed hundreds of millions of years earlier than previously thought, suggesting a habitable environment for life. The study used unique instruments to count strontium atoms in ancient rocks and found silica presence, altering the classic view of early Earth.
The subduction of the Pacific plate resulted in the thinning and replacement of the lithospheric mantle in the North China Craton. The Yanshan Movement, a decratonization process, was characterized by lithospheric thinning and crustal detachment triggered by asthenospheric upwelling.
Seismologists have discovered that processes beneath the Andean Plateau produce far more continental rock than previously thought. The findings suggest that mountain-forming regions could create larger volumes of continental crust in less time, leading to significant changes in our understanding of Earth's geological history.
Scientists use computer simulations to analyze the evolution of plate tectonics on Earth over the past 3 billion years. They demonstrate that continents have been recycled and transformed throughout history.
Researchers propose alternative petrogenesis model for Archean trondhjemite, suggesting tonalitic rocks as primary source material. Simulations using quantitative phase modeling approach reveal comparable major and trace element compositions with trondhjemite rocks.
Researchers computed precise amount of continental crust before and after collision, concluding that half the mass is missing due to sinking into mantle. The finding explains puzzling geochemistry and throws out long-held idea that continental crust can't descend into mantle.
The ChemCam instrument on NASA's Curiosity rover has found evidence of ancient, light-colored rocks on Mars that are rich in feldspar and quartz, similar to those found in the Earth's granitic continental crust. These discoveries suggest that Mars may have had a primitive continental crust around 4 billion years ago.
Researchers from the University of Liverpool found that south east Iceland is actually composed of a fragment of continental crust, extending offshore to the east. This discovery has significant implications for our understanding of mantle plumes and plate tectonics, with potential impacts on natural resources in the region.
Researchers reveal 'juvenile' continental crust has been produced throughout Earth's history, contradicting the long-held theory that all continental crust was generated during the Archaean Eon. The study provides new understanding of the formation of the Earth's continental crust and its impact on the planet's life and climate.
Researchers find that the Earth's crust formed relatively slowly from 1.7 to 0.75 billion years ago, with little activity and stable environments, before speeding up, potentially inducing evolutionary changes. This discovery has implications for the interpretation of climate models.
Researchers from GFZ, University of Sydney, and University of London discovered that the centre of a rift migrates laterally during continental break-up, causing asymmetry in continental margins. This process leads to the formation of thin crustal slivers on one side and more pronounced asymmetry due to faster extension velocity.
Researchers have uncovered evidence of ancient protocontinental crust in four-billion-year-old rocks from the Acasta Gneiss Complex. The study suggests that processes similar to those occurring in present-day Iceland may have formed the Earth's first continents.
Researchers develop new tomographic approach to image shallow seismic velocity structure, revealing subducting continental crust for the first time. This allows for early detection of landslides and earthquakes in Central Asia.
New research in Geosphere reveals ancient marine terraces using airborne LiDAR, assesses impact of program selection on 3D geologic models, and creates emergent models for Tonga Trench and Samoa Archipelago. These studies showcase the latest advancements in geoscience modeling, education, and research.
Researchers propose that oceanic crust 'oozed' continents at depths of 30-40 kilometers instead of 100 km, supported by analysis of oldest rocks. This new theory challenges the conventional understanding of continental crust formation.
Research highlights the age of continental crust, with over 60% originating in the Archean, 2.5 billion years ago. A new paleomagnetic pole for chron 32 corrects for spreading-rate dependence, improving skewness data accuracy. Seismic ambient noise analysis reveals structural alignments in the Chile Ridge Subduction Region.
A team of scientists has created a curved cross-section of the North American continent, extending from the Cascadia subduction zone to the Atlantic margin. The cross-section reveals scars of ancient continental collisions and eons of oceanic subduction, indicating processes that have shaped the continent for over three billion years.
Researchers at the University of Bristol have developed a new methodology for calculating model ages of continental crust formation. This approach uses the isotope composition of newly formed crust to estimate age, resulting in significantly younger and more consistent dates than previous methods based on mantle isotopes.
Researchers have discovered that the Indian continental crust was forced down to a depth of at least 200 km under the Asian plate during the Himalayan collision. This finding is significant as it contradicts previous estimates and challenges fundamental parameters of Himalayan tectonics.