Articles tagged with Lithosphere
Researchers found that a dense piece of lithospheric mantle beneath the Hangay Mountains broke off and sank into the deeper mantle about 125-114 million years ago. This 'foundering' event triggered melting of the mantle, generated magma, and caused the overlying crust to dome upward.
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 discover that asthenosphere composition controls magma flux and spreading mode at slow- to ultraslow-spreading ridges. The study found higher volumes of ancient refractory mantle domains in the asthenosphere during asymmetric spreading, supporting the hypothesis that the asthenosphere modulates magma flux.
Researchers have discovered that the underside of the North American continent is experiencing 'cratonic thinning', a phenomenon where the continent is slowly losing its stability and rock layers. This process, driven by the subduction of the Farallon Plate, may eventually stop as the plate sinks deeper into the mantle.
New research from Macquarie University identifies the probable locations and mechanisms of accumulations of critical metals at the margins of old cores of continents. These areas have been found to contain more sulfur and copper than elsewhere on the continents, making them potential targets for future exploration activities.
Researchers confirm multi-stage lithospheric dripping as cause of basin subsidence in Central Anatolian Plateau. Laboratory experiments and satellite data reveal intricate connection between plateau uplift and basin formation events.
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.
A team of researchers from Japan found that water enhances energy dispersion and reduces elastic moduli in rocks, leading to increased seismic wave attenuation. The study suggests the oceanic asthenosphere must contain water, explaining sharp velocity drops and near-constant attenuation observed at the LAB.
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.
New research from Rice University suggests that ancient microorganisms helped cause massive volcanic events by facilitating the precipitation of minerals in banded iron formations. The study provides insight into processes that could produce habitable exoplanets and reframes scientists' understanding of Earth's early history.
Researchers confirm that water causes incipient melting, leading to reduced S-wave velocity and enhanced electrical conductivity. The presence of low-velocity zones in continental China is attributed to basal hydration weakening the lithosphere, converting it into asthenosphere.
Researchers have discovered a new layer of partly molten rock under the Earth's crust that helps settle a long-standing debate about how tectonic plates move. The study reveals that the melt layer has no significant influence on plate tectonics, with convection of heat and rock being the prevailing force.
Scientists from the University of Arizona have discovered a giant active mantle plume pushing the surface of Mars upward, causing earthquakes and volcanic eruptions. The finding suggests that Mars' deceptively quiet surface may hide a more tumultuous interior than previously thought.
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 recent seismic study reveals that Patagonia is rising as glaciers melt due to a gap in the tectonic plate under the region. The study found low seismic velocity and a thinning of the lithosphere above the gap, which is driving rapid uplift.
Research reveals that magmas from Mount Etna and Mount Vulture have extremely high Nb/Ta ratios, indicating a deep carbon-rich lithospheric mantle beneath southern Italy. This process contributes significantly to global volcanic CO2 emissions.
Researchers study feldspar recycling in Yosemite National Park's Tuolumne intrusive complex to understand incremental growth processes. A new model predicts relationships between hanging-wall extension, fault slip, and fault dip for the Ragged Mountain Fault in Alaska.
Compressive stresses in the lithosphere induce grain mixing and damage, generating vertical weak bands that facilitate subduction initiation. These weak zones are susceptible to bending associated with subduction and may provide insight into plate tectonics on Earth.
A rare earth element deposit has been identified in the Mountain Pass region of the eastern Mojave Desert, USA. The deposit is believed to be magmatic carbonatite and spans a significant subsurface extent, according to a recent study published in Geosphere.
A recent study on the 2017-2018 Montecito debris flow reveals that road culverts and bridge underpasses played a significant role in causing widespread damage, as they redirected debris flow into neighborhoods. The research provides rare spatial and dynamic constraints for testing debris-flow runout models.
A new study published in Geosphere investigates how scientists perceive interactions with policy makers, revealing five distinct models: a beacon, collaborator, educator, outcast, and investigator. The researchers emphasize the importance of understanding individual perspectives to effectively engage scientists in policy decisions.
A new study published in Lithosphere found that Permian volcanism contributed to increased atmospheric greenhouse gas content in Antarctica. The researchers analyzed age and isotopic data from zircon minerals, expanding the known distribution of Choiyoi-related deposits and highlighting the importance of subduction-related volcanism.
A new study published in Geosphere reveals that two major faults in Emerald Bay have been moving vertically over the past 20,000 years, with no strike slip motion. The research used a combination of deep dives, bathymetry surveys, and LiDAR data to create high-resolution maps of the bay's geology.
A new study found that the Siberian Flood Basalts, a massive volcanic eruption around 250 million years ago, sent nearly 90% of life into extinction. The team discovered that chlorine, bromine, and iodine in the lithosphere were released into the atmosphere, destroying the ozone layer.
The Jiachala Formation, a key deposit in the Neo-Tethyan subduction zone, was formed in a submarine fan environment during Late Cretaceous (~88-84 Ma) at the active southern margin of the Asian plate. Provenance analysis indicates it originated from the Gangdese arc and central Lhasa terrane.
The study identifies at least three tears in the Indian mantle lithosphere underthrusting the Himalayas. This model explains patterns of crustal deformation and east-west extension in southern Tibet, providing insights into the region's seismic activity.
Seismic reflection data from the 2011 Tohoku-oki earthquake revealed a frontal prism, reflective zone, and subducted horst-and-graben structures in the Japan Trench. This provides insights into the behavior of large shallow slip zones and potential tsunami earthquakes.
A study of the 1755 Lisbon earthquake reveals a lack of knowledge among Portuguese citizens about tsunamis, yet most recognize the importance of learning more. The authors advocate for including historical and scientific issues in geosciences programs to address seismic risks and responses.
Scientists drilled three 2-km-deep holes to explore the geology of a scientific borehole in the Snake River Plain. They found evidence of heat and older hydrothermal interactions, but no geothermal energy production due to a cool water aquifer.
Geologists explore how various rock types, particularly carbonates, influenced Union and Confederate commander's decisions. The rolling terrain of Gettysburg and other battlefields was limited by carbonate rocks, which provided natural defensive positions.
A 54.5 million cubic meter snow avalanche occurred in western Colorado, killing three people. The study used large-scale field mapping and seismic signals to analyze the avalanche's movement phases, shedding light on rock-avalanche modeling and ongoing hazards.
New mapping and dating reveal timing of past earthquakes and tectonic deformation distribution across the western U.S. Death Valley's faulted alluvial fans help determine seismic hazard mitigation and understand great landscapes' evolution over recent geologic time.
Two new studies shed light on the Himalayan tectonic system, confirming a strike-slip dominated fault in western Nepal and highlighting topographic and tectonic discontinuities. The findings also support the initiation of mountain belt-parallel extension in the mid-Miocene epoch.
Researchers have uncovered new insights into the structural controls of fluid pathways in an active rift system, with potential implications for geothermal exploration. The study focuses on Aluto volcano, a major source of geothermal energy in Ethiopia's Rift Valley.
The study finds that the Dinner Creek Tuff Eruptive Center was a common source for mafic and silicic magmatism, linking the GRB eruptions and providing evidence for the location of Columbia River Basalt storage sites. This suggests that shallow crustal rhyolitic reservoirs played a key role in controlling the timing and place of eruption.
Three tectonic processes, including uplift, reduced solar irradiation, and an axis shift, created conditions for Greenland's glaciation. The interaction of these processes, driven by the Iceland plume, led to the formation of ice on Greenland.
Researchers have uncovered new seismic data for the Slate Range in California, revealing a change in faulting style around four million years ago. In another study, scientists linked zircon ages to oxygen isotopic correlations between two tephra deposits in the southwestern United States.
Researchers analyzed detrital zircons from passive margin strata in western North America, revealing variations in ages and Hf isotope compositions that provide insights into the provenance of Cordilleran passive margin strata. Strike-slip faulting along the Wassuk Range of the northern Walker Lane, Nevada, was also studied, providing ...
This issue of Lithosphere features studies on the Great Slave Lake shear zone in northwest Canada, which provides insight into the deep structure of ancient mountain belts. The research also explores the tectonic development of the Tibetan Plateau, revealing that faults responsible for its formation are restricted within the crust.
Two special issues of Geosphere cover the India-Asia collision in the Himalaya and the origin of the Colorado River System II. The articles also explore other geological features such as the Jemez Mountains volcanic field and the Alabama and western Georgia Blue Ridge.
The Geological Society of America's Geosphere journal has added four special issues exploring the Sierra Nevada, Colorado River system, Laurentia, and the deep sea. New research reveals that Basin and Range volcanism was triggered by extensional tectonics, while Cenozoic erosion in southwestern North America was linked to surface uplif...
A new Geosphere study uses virtual fieldwork to analyze terrain data from the 2010 Haiti earthquake, revealing evidence of active faulting and ancient surface rupture. The research also explores the provenance of sandstones in the Colton Formation and the interactions between the Seattle and Saddle Mountain faults.
A study on Valles Marineris fault zone on Mars suggests left-slip transtensional deformation. In Iraq, a 'missing' Cretaceous arc assemblage has been identified in the Zagros orogenic belt. The Okanagan Valley shear zone in Canada has new age constraints and Phanerozoic protoliths for footwall gneisses.
This Geosphere special issue delves into the formation and transport of ancient oceanic rocks in southeastern Yukon, Canada. New techniques are also employed to study flat-topped seafloor mounds beneath the Ross Sea, which may be of volcanic origin.
The November GSA Today science article explores why the Southern Gulf of California ruptured so rapidly, attributing it to an oblique divergence across a thin and hot, weak lithosphere. This process allowed for rapid deformation and stretching of the crust, resulting in new sea floor formation in just 6-10 million years.
Two studies examine the Jemez-Embudo Accommodation Zone in New Mexico and the Tennessee Salient in Appalachia, shedding light on tectonic processes. Geodynamic models and paleomagnetic data reveal no statistically significant rotation in the Rio Grande Rift and indicate a more complex history of curvature formation.
A new themed issue of Geosphere delves into the geology and tectonic history of northern San Francisco Bay region, featuring studies on sedimentary and volcanic deposits cut by active strike-slip faults. The papers provide insights into groundwater hydrology, seismic hazard, and plate margin evolution.
The April 2011 Geosphere issue features articles on exploring the deep sea, including modeling of submarine cyclic steps, linking tectonism to deep-sea sedimentation, and submarine canyon profiles. New developments in Grenville geology also highlight fresh insights into the Lyon Mountain Granite.
The February 2011 Geosphere issue explores recent advances in Grenville geology, including pegmatite geochronology and 3D characterization of sandstone using X-ray CT. This themed issue honors James McLelland's contributions to understanding the Grenville Province.
This issue of Geosphere highlights the geological processes that produce magma pulses and sheets in tabular intrusions. The study reveals a link between shallow igneous intrusions and volcanic activity, demonstrating how intrusive sheeting can destabilize volcano flanks and trigger eruptions.
A study analyzing oxygen in snail shells reveals climate-driven environmental change in Tibet's Zhada basin over the last 6 million years. Geophysical data also reveal the geological history of Pahrump and Mesquite Valleys, USA, with two distinct phases of extension and tectonic shearing.
A magnetic study of the Colima volcanic complex in Mexico reveals that faults exhibit distinct magnetic anomalies, which can be used to improve geological interpretations. The findings have significant implications for hazard assessments in densely populated areas around active volcanoes.
Recent studies uncover new insights into the Miocene structural reorganization of the South Tibetan detachment, eastern Himalaya, and its implications for understanding continental collision. Additionally, researchers have developed a one-dimensional modeling approach to quantify dip and velocity of continental subduction from high-pre...
Researchers investigate strange river behavior in Arizona, attributing it to ancient tectonic extension. In another paper, scientists study active low-angle normal faults in Mexico, resolving a long-standing controversy on their existence.
The Geosphere journal features two studies: one on climate change in the southwestern US from 17-6 million years ago, and another on the evolution of the South Balkan extensional system. The climate study used sedimentation and erosion history to interpret changes in ocean circulation and North American monsoon activity.
This paper describes network analyses capabilities within GIS to describe and quantify shear zone networks. Meanwhile, structural analysis of rockslide avalanches reveals fault structures as fingerprints for motion and emplacement styles.
Geologists use seismic waves to locate missing rock under Tibet, clarifying how continents behave when they collide. The research helps solve a long-standing mystery and provides key evidence for understanding the full dynamics of continental collision.
A graduate student's seismic study has found a sharp dividing line between the lithosphere and asthenosphere, contradicting the idea that the transition is gradual. The research suggests water or partly molten rock must be present in the asthenosphere to cause such an abrupt change.
Studies reveal steady rate of oceanic lithosphere creation over past 180 million years, contrasting with decreasing estimates. Researchers analyze structural investigation of San Juan thrust system and kinematic history of central Andean fold-thrust belt to build high plateaus.