Category: Geologic History

Scientists find fossil of dinosaur ‘killed on day of asteroid strike’

4/8/2022

Scientists believe they have been given an extraordinary view of the last day of the dinosaurs after they discovered the fossil of an animal they believe died that day. The perfectly preserved leg, which even includes remnants of the animal’s skin, can be accurately dated to the time the asteroid that brought about the dinosaurs’ extinction struck Earth 66m years ago, experts say, because of the presence of debris from the impact, which rained down only in its immediate aftermath. - Guardian

Longest known continuous record of the Paleozoic discovered in Yukon wilderness

1/12/2022

Hundreds of millions of years ago, in the middle of what would eventually become Canada’s Yukon Territory, an ocean swirled with armored trilobites, clam-like brachiopods and soft, squishy creatures akin to slugs and squid. A trove of fossils and rock layers formed on that ancient ocean floor have now been unearthed by an international team of scientists along the banks of the Peel River a few hundred miles south of the Arctic’s Beaufort Sea. The discovery reveals oxygen changes at the seafloor across nearly 120 million years of the early Paleozoic era, a time that fostered the most rapid development and diversification of complex, multi-cellular life in Earth’s history. “It’s unheard of to have that much of Earth’s history in one place,” said Stanford University geological scientist Erik Sperling, lead author of a July 7 study detailing the team’s findings in Science Advances. Most rock formations from the Paleozoic Era have been broken up by tectonic forces or eroded over time. “There’s nowhere else in the world that I know of where you can study that long a record of Earth history, where there’s basically no change in things like water depth or basin type.” - Geology Page

Ancient spider caring for her offspring is trapped in 99 million-year-old amber

9/20/2021

Nothing gets between a fiercely protective mother spider and her children. Dripping tree resin trapped adult female spiders and baby spiderlings about 99 million years ago, forever showcasing the maternal care exhibited by these arthropods, according to new research. The Lagonomegopidae family of spiders is now extinct, but spiders have a long history and first appeared during the Carboniferous period between 359 to 299 million years ago.
The fossilized Burmese amber pieces tell two different stories. A study detailing the observations of the amber specimens published Tuesday in the journal Proceedings of the Royal Society B: Biological Sciences. - CNN and The Royal Society

Why Variations in Earth's Magnetic Field Aren't Causing Today's Climate Change

9/8/2021

Some people have claimed that variations in Earth’s magnetic field are contributing to current global warming and can cause catastrophic climate change. However, the science doesn’t support that argument. In this blog, we’ll examine a number of proposed hypotheses regarding the effects of changes in Earth’s magnetic field on climate. We’ll also discuss physics-based reasons why changes in the magnetic field can’t impact climate. - NASA

Don’t Call It a Supervolcano

8/13/2021

Scientists dismantle the myths of Yellowstone: Yellowstone National Park, the world’s first and arguably most famous national park, is home to one of the planet’s largest and potentially most destructive volcanoes. The 50- by 70-kilometer Yellowstone caldera complex is so massive that it can really be appreciated only from the air. But although the caldera isn’t always visible on the ground, it’s certainly no secret: Copious thermal features like hot springs and geyser basins dot the landscape and have attracted people to the uniquely beautiful and ecologically rich area for at least 11,000 years. - EOS

Right - The movement of the North American tectonic plate over the Yellowstone hot spot has created a trail of volcanic activity across southern Idaho into Wyoming over the past 16.5 million years. Credit: USGS. Click image for larger version.

The Long Decline of Arctic Sea Ice

1/5/2021

Forty years of satellite data show that 2020 was just the latest in a decades-long decline of Arctic sea ice. In a review of scientific literature, polar scientists Julienne Stroeve and Dirk Notz outlined some of these changes: In addition to shrinking ice cover, melting seasons are getting longer and sea ice is losing its longevity. The longer melting seasons are the result of increasingly earlier starts to spring melting and ever-later starts to freeze-up in autumn. The map above shows trends in the onset of freeze-up from 1979 through 2019. Averaged across the entire Arctic Ocean, freeze-up is happening about a week later per decade. That equates to nearly one month later since the start of the satellite record in 1979. - Earth Observatory / NASA

Geologists Raise the Speed Limit for How Fast Continental Crust can Form

10/9/2020

Scientists have thought that the Earth's mountain ranges are formed through this process over many millions of years. But MIT geologists have now found that the planet can generate new land far more quickly than previously thought. In a paper published in the journal Geology, the team shows that parts of the Sierra Nevada mountain range in California rose up surprisingly fast, over a period of just 1.39 million years—more than twice as fast as expected for the region. The researchers attribute the rapid formation of land to a massive flare-up of magma.- Phys.Org

Meteorite Crater Discovered Drilling for Outback Gold Estimated to Be 100MY

9/25/2020

Geologists say they have discovered a large meteorite crater in outback Western Australia, which could be up to five times bigger than the famous Wolfe Creek Crater in the state's remote north. A team of geologists led by geological consultant Dr Jayson Meyers is behind the discovery in WA's Goldfields Initial estimates suggest the asteroid that created the crater collided with the Earth 100 million years ago. It is not visible from the surface but electromagnetic surveys, which map the rocks below, suggest the crater has a diameter of around 5 kilometres. - ABC (Australia)