Tag

Geology

All articles tagged with #geology

science8 hours ago•9 min saved

First Brazilian Tektite Field Traces 6.3-Million-Year Cosmic Impact

Brazilian researchers have identified the country’s first tektite field, Geraisites, a collection of glassy fragments spread across Minas Gerais and adjacent states that indicate a substantial ancient impact. Dating with 40Ar/39Ar places the event at about 6.3 million years ago, during the Miocene, with isotopic signatures pointing to a very old continental crust source in the São Francisco craton. The field now spans over 900 km, and while no crater is yet known, the data imply a powerful impact with dispersed molten material; researchers plan aerogeophysical surveys and modeling to estimate the event’s energy, velocity, and crater geometry. This discovery expands South America’s sparse tektite record and suggests tektites may be more common than previously thought.

via SciTechDaily|

#brazil #geology #impact

planet-earth1 day ago•68 min saved

China’s forest hides Earth's youngest major crater

A 1.15-mile-wide, incomplete crater in Heilongjiang, China—the Yilan crater—is believed to be the youngest major impact structure on Earth, dating roughly 46,000–53,000 years ago. Discovered in 2021 after forest cover concealed it, the ringed feature is the largest known crater of its age and could be younger than Barringer Crater, though age estimates remain uncertain.

via Live Science|

#china #earth-from-space #geology

science3 days ago•17 min saved

Deep mantle shift links rivers as Green River climbs 100 miles

Geologists say a deep lithospheric drip beneath the Uintas briefly lowered a barrier, allowing the Green River to cut uphill and merge with the Colorado River for about 99–100 miles in northeastern Utah. The event is dated to roughly 2.3–4.7 million years ago and is supported by sediment records and seismic imaging showing a mantle root beneath the mountains. This deep-earth movement helped shift the continental drainage divide, enabled fish to mix between basins, and helped carve the Canyon of Lodore, illustrating how subterranean processes shape surface rivers.

via Earth.com|

#geology #green-river #lithospheric-drip

science7 days ago•4 min saved

NASA Space Photo Highlights Zimbabwe’s 2.5-Billion-Year Great Dyke

NASA’s astronaut photo from the ISS showcases Zimbabwe’s Great Dyke—a 2.5-billion-year-old lopolith that runs about 550 kilometers through central Zimbabwe. Rich in platinum, chromite, copper, iron, and nickel, the Dyke is both a major mineral resource and a window into Earth's early tectonic history; space-based observations help map its extent and monitor changes impacting mining and the environment.

via Indian Defence Review|

#geology #great-dyke #mining

science7 days ago•4 min saved

Antarctic ice yields record-breaking 23-million-year climate core

An international SWAIS2C team drilled a 523‑metre hole through West Antarctica’s Crary Ice Rise to recover a 228‑metre sediment core—the deepest ever retrieved beneath an ice sheet. Preliminary dating, based on fossilized algae, suggests a 23‑million-year archive that includes warmer-than-present periods, providing new insight into how far the West Antarctic Ice Sheet has retreated in the past and whether warming could trigger irreversible loss, with significant implications for future sea levels.

via Nature|

#antarctica #climate-change #geology

science8 days ago•7 min saved

Mantle Drip Enables a River to Slice 100 Miles Through Utah's Uintas

Scientists propose that lithospheric dripping beneath the 13,000‑foot Uintas lowered the mountains, allowing the Green River to carve a continuous 100‑mile path through hard limestone and sandstone; seismic tomography reveals a deep mantle blob consistent with this process, and dating suggests the river’s current course formed about 2–5 million years ago, solving a long‑standing canyon puzzle.

via Indian Defence Review|

#geology #geomorphology #green-river

environment10 days ago•18 min saved

Pink Granite Unlocks Hidden Giant Beneath Antarctica's Ice

Pink granite boulders found in Antarctica’s Hudson Mountains led scientists to discover a massive granite deposit buried beneath Pine Island Glacier, linking surface clues to the glacier’s past flow and improving predictions of future sea‑level rise.

via Earth.com|

#antarctica #environment #geology

science11 days ago•7 min saved

Antarctica Reveals a 175-Million-Year-Old Subglacial Granite Giant

Researchers using gravity surveys and radiometric dating have uncovered a vast 100-km-wide, 7-km-thick granite deposit buried beneath Pine Island Glacier, dating to about 175 million years ago. The discovery sheds light on subglacial topography, ice-sheet dynamics, and could improve predictions of future sea-level rise.

via Indian Defence Review|

#antarctica #geology #ice-sheet

science16 days ago•5 min saved

500-KM Oceanic Canyon Traced to a Tectonic Zipper, Not Erosion

Scientists mapped the King’s Trough, a 500+ km underwater canyon in the North Atlantic, and determined it formed over millions of years by the slow separation of the European and African plates via a tectonic 'zipper,' aided by unusually thick, hot crust from the Azores mantle plume. The finding, reported after METEOR expedition data and high‑resolution sonar, links deep mantle processes to surface tectonics and reshapes how we think about underwater canyon formation.

via The Daily Galaxy|

#geology #kings-trough #mantle-plume

science19 days ago•5 min saved

CSIRO Uncovers Country-Shaped Magnetic Signature Beneath Australia’s Northern Territory

CSIRO researchers have identified a distinct, country-shaped magnetic anomaly beneath the Northern Territory. By applying new modeling techniques and a refined grid algorithm, they produced clearer images of crustal structures, improving geological mapping and paving the way for future mineral exploration.

via Indian Defence Review|

#australia #csiro #geology

science20 days ago•129 min saved

Earth's Hidden Weight Explains Why the Green River Seems to Flow Uphill

A new study explains the Green River’s uphill illusion: a dense lithospheric root beneath the Uinta Mountains slowly sank into the mantle for millions of years, dragging the surface downward. When the root detached a few million years ago, the mountains rose again, leaving the river looking like it flows uphill while gravity remains unchanged.

via The Daily Beast|

#colorado-river #geology #green-river

planet-earth21 days ago•60 min saved

Country-shaped magnetic anomaly reveals buried geology beneath Northern Territory

Advanced modeling of magnetic data from Australia’s Northern Territory has uncovered a large magnetic anomaly shaped like the country, revealing buried geological boundaries and structures (faults, folds, basins) that conventional maps missed. Led by CSIRO researchers, the work refines the 1999 Bonney Well Survey data with a new gridding algorithm, producing clearer imagery and offering clues about Australia’s geological history and potential mineral resources, including hidden features exposed at the surface in the Hatches Creek Formation dating to 2.5–1.6 billion years ago.

via Live Science|

#australia #csiro #geology

science21 days ago•2 min saved

Lithospheric Drip Redirected a River Across Utah's Uinta Mountains

Geologists propose that a dense chunk at the base of the Uinta Mountains’ lithosphere ‘dripped’ into Earth’s mantle, temporarily pulling the range downward and allowing the Green River to cut perpendicularly across the mountains to join the Colorado River, forming the Canyon of Lodor. Seismic imaging reveals a ~200 km-deep, cold chunk and thinner crust beneath the range; after the drip broke free about 2–5 million years ago, the mountains rebounded, the canyon solidified, and the Green River became a Colorado River tributary, reshaping North America’s continental divide.

via ScienceAlert|

#colorado-river #geology #green-river

science21 days ago•5 min saved

Zealandia Declared: Earth's Hidden Eighth Continent Unveiled Beneath the Pacific

Scientists have formally recognized Zealandia as Earth's eighth continent—spanning about five million square kilometers with more than 94% submerged in the Pacific—after International Ocean Discovery Program drilling and peer‑reviewed studies showing it meets continental criteria (thicker crust, coherent landmass, and ancient terrestrial fossils). This confirmation reshapes our understanding of Earth’s crust and could influence future maritime claims and exploration.

via Indian Defence Review|

#continent #geology #iodp

science22 days ago•6 min saved

Mantle Drip Carved the Green River Through Utah's Uinta Mountains

Geologists say a lithospheric drip—dense lower-crust material sinking into the mantle—pulled the land downward beneath Utah's Uinta Mountains, creating a temporary depression that let the Green River punch a 700-meter canyon through the range around 8 million years ago; as the drip broke off and the crust rebounded, the river remained entrenched, reshaping North America’s hydrology and the continental divide, with seismic imaging and river-network modeling supporting the scenario.

via The Daily Galaxy|

#geology #green-river #lithospheric-drip