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Mystery solved: Scientists document motion of rocks at Death Valley’s Racetrack Playa

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Study solves mystery of Death Valley’s moving rocks. Photo courtesy National Park Service.

Wind, water and ice are shown once again to be key geological drivers

Staff Report

FRISCO — Scientists have not only solved the mystery of the moving rocks at Death Valley’s Racetrack Playa — they documented the movement on video and even took measurements by attaching GPS units to some “non-native” rocks as part of a research project in the Southern California desert.

Some of the rocks weigh up to 100 pounds and leave behind distinct tracks as they scoot across the dry lake bed. Scientists have been studying the area for decades, but nobody has seen the process in action until now, according to a press release from the Scripps Institution of Oceanography (UC San Diego). Continue reading

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Study: Lightning a major factor in shaping mountains

Compass readings help trace the impact of electrical storms

Summit County Colorado monsoon season.

A bolt of lightning strikes near the Continental Divide, in Summit County, Colorado.

By Summit Voice

Geologists in South Africa say that lighting strikes are significant factor in shaping the summit areas of mountains, thereby shaping the evolution of mountain landscapes. Specifically, they found that many angular rock formations in the Drakensberg Mountains are caused by lightning blasts — and not necessarily by the melt-freeze cycle as commonly assumed. Continue reading

Massive rockslide closes parts of Dinosaur Nat’l Monument

100-foot chunk of rock breaks off canyon wall

The large lighter-colored area indicates the extent of the rock slide above Jones Hole Creek as seen from the fish hatchery

The large lighter-colored area indicates the extent of the rock slide above Jones Hole Creek as seen from the fish hatchery in Dinosaur National Monument. Photo via NPS.

By Summit Voice

FRISCO — A rockslide has closed portions of Dinosaur National Monument, According to the National Park Service, the slide has resulted in the closure of NPS lands from the boundary of the monument and the U.S. Fish and Wildlife Service hatchery to Ely Creek.

The first rock slide was reported June 18, when a large slab of rock broke free from a cliff face just a short distance inside the monument boundary, less than .25 miles from the Jones Hole Fish Hatchery. One fisherman reported having to run from a boulder that landed in the stream not too far from his location. After receiving reports, park rangers checked the scene and did not see any further activity. Continue reading

Volcano study helps measure historic ice sheet thickness

UBC geologists examine pyroclastic deposits near summit of tephra cone on south side of Kima'Kho. Key attributes of these deposits established that they were deposited above the level of a surrounding englacial lake.

UBC geologists examine pyroclastic deposits near summit of tephra cone on south side of Kima’Kho. Key attributes of these deposits established that they were deposited above the level of a surrounding englacial lake. Photo courtesy UBC Science.

Ancient tuyas hold climate clues

By Summit Voice

FRISCO —In what must have been incredible displays of fire and ice, ancient volcanoes once erupted under massive glacial ice sheets, leaving deposits that could help paleoclimatologists unravel some ice age puzzles.

In a recent study, University of British Columbia researchers surveyed those deposits at the Kima’ Kho tuya, which erupted under an ice sheet about 1.8 million years ago. Their findings suggest that he ancient regional ice sheet through which the volcano erupted was twice as thick as previously estimated. Continue reading

Does climate affect volcanic activity?

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Mt. St. Helens erupts in 1980. Photo courtesy USGS.

New research suggests melting ice sheets could trigger more vulcanism

By Summit Voice

SUMMIT COUNTY — Melting ice sheets may trigger an increase in global volcanic activity, according to researchers with the GEOMAR Helmholtz Centre for Ocean Research (based in Kiel, Germany), and Harvard, who matched historic geological records of vulcanism with warm climate periods.

“In times of global warming, glaciers on the continents are melting relatively quickly. At the same time the sea level rises. The weight on the continents decreases, while the weight on the oceanic tectonic plates increases. Thus, the stress changes within in the earth to open more routes for ascending magma,” said GEOMAR’s Dr Mario Jegen. Continue reading

The Grand Canyon gets a new birthday

New geologic technique suggests the Grand Canyon is 60 million years older than previously thought

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There’s no better place to contemplate Earth’s geological mysteries than the rim of the Grand Canyon, which may be quite a bit older than scientists had thought. Photo by Leigh Wadden.

By Summit Voice

SUMMIT COUNTY — When you stand on the edge of the Grand Canyon, it becomes a little easier to visualize the almost unimaginably powerful forces that give Earth the shape we know today — and also to get a sense of how long some of those processes have been at work.

New research led by CU-Boulder assistant professor Rebecca Flowers suggests that the Grand Canyon may be 60 million years older than previously thought. An analysis of mineral grains from the bottom of the western Grand Canyon indicates it was largely carved out by about 70 million years ago — a time when dinosaurs were around and may have even peeked over the rim.

The scientists used a dating method that exploits the radioactive decay of uranium and thorium atoms to helium atoms in a phosphate mineral known as apatite, said Flowers, a faculty member in CU-Boulder’s geological sciences department. The technique may help researchers unravel other geological mysteries. Continue reading

Rogue waves, not tsunamis, move Aran Island rocks

Careful mapping, anecdotal evidence and radiocarbon-dated clams tell the true story

A view over the karst landscape on Inishmore, from Dún Aengus, an ancient stone fort. PHOTO VIA WIKIMEDIA COMMONS.

By Summit Voice

SUMMIT COUNTY — Seemingly made of sheer rock, the Aran Islands, off the coast of Ireland, look like they were built to withstand the stormy waters of the North Atlantic forever.

But new research suggests the sea has enough force to push ridges of giant boulders — some weighing as much as 78 tons — far inland from the edge of the imposing cliffs.

Many geologists had long speculated that only a tsunami could have enough force to rearrange the massive slabs of limestone. Armed with equations that model the forces generated by waves, some researchers concluded that no ordinary ocean waves could muster the force necessary to move the largest of the boulders this high above the ocean surface and so far inland. The math suggests the rocks in the ridges could only have been put there by a tsunami. Continue reading

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