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Geology NWT_Earth SCI

Scientists believe diamonds are under Earth’s surface

According to an international team of scientists, there may be quadrillion tons of diamonds under the surface of the Earth. The deposits are in cratonic roots between 90 and 150 miles below the surface.

“This shows that diamond is not perhaps this exotic mineral, but on the (geological) scale of things it’s relatively common,” said Ulrich Faul, co-author of the study and a research scientist at MIT. They discovered there is much more diamond than they ever thought there could be.

MIT News describes cratons as the oldest and most immovable sections of rock. They are stable chunks of the Earth’s crust and are in the shape of inverted mountains.

The deepest parts are the roots that can reach all the way to the Earth’s mantle. The authors of the study believe the diamonds are in the mantle.

They used seismic data – or recorded sound waves from seismic activity to locate the diamonds. This data helped them measure what the Earth is made of.

Then, the team used 3D modeling to create virtual rocks in a quest to figure out what substances could compose the roots of cratons. Diamonds seemed to foot the bill.

The diamonds matched the velocity of the sound traveling through the roots. They estimated that the roots must be made of 1 to 2 percent diamond.

Using this estimate, and the number of known craton roots, the scientists arrived at their quadrillion-ton estimate. It is 1,000 times more than they first thought.

 

Categories
Geology Research SCI

Study reveals new clues about Great Dying, Earth’s largest mass extinction

A new study sheds light on the causes of the largest mass extinction in the Earth’s history, also referred to as the End-Permian Extinction and the Great Dying.

The event took place approximately 250 million years ago when a giant volcanic eruption hit what is now Russia’s province of Siberia. The eruption sent almost 90 percent of life into extinction. In geology, the eruption is referred to as the Siberian Flood Basalts, which ran for nearly one million years.

“The scale of this extinction was so incredible that scientists have often wondered what made the Siberian Flood Basalts so much more deadly than other similar eruptions,” said Michael Broadley of the Centre for Petrographic and Geochemical Research in Vandœuvre-lès-Nancy, France, and lead author of the study.

The research was co-authored by the late Lawrence Taylor, who is the former director of the Planetary Geosciences Institute at the University of Tennessee, Knoxville.

“Taylor was instrumental in supplying samples of mantle xenoliths, rock sections of the lithosphere [a section of the planet located between the crust and the mantle] that get captured by the passing magma and erupted to the surface during the volcanic explosion,” Broadley said. “Taylor also provided advice throughout the study.”

The team analyzed samples to determine the lithosphere composition, which revealed that prior to the Siberian Basalt floods, it was loaded with bromine, iodine, and chlorine, all of which belong to the halogen chemical group. After the volcanic eruption, they disappeared.

“We concluded that the large reservoir of halogens that was stored in the Siberian lithosphere was sent into the earth’s atmosphere during the volcanic explosion, effectively destroying the ozone layer at the time and contributing to the mass extinction,” Broadley said.

The findings were published in Nature Geoscience.

Categories
Archaeology Geology Science

New process makes instant fossils

A team of paleontologists believe they have discovered a way to quickly create fossils, technology that could potentially lead to new research on how the Earth preserves different organisms over time.

The study of fossils is known as taphonomy, and it has been around since the 1950’s. While the process is a key part of paleontology, it is used across various scientific fields to better understand the way organisms fossilize.

Such information is important because it sheds light on what animals are over-represented in the fossil record, and helps researchers better understand larger trends like time scales and climate change.

“Basically it’s about the process of death and disintegration,” said Ronald Martin, a paleontologist at the University of Delaware who was not involved in the study, according to Popular Science

To gain insight into that process, scientists often find ways to create their own fossils. That includes a 1993 project where a team buried marine species beneath the Gulf of Mexico and monitored their decay over time.

However, while such experiments provide results, they are also greatly limited. Not only do most of them occur within closed containers that make it hard to see what is going on, they also take place away from the influence of outside factors like predators or earthquakes.

Not to mention they take a long, long time to make.

To fix those problems, a group of international researchers came up with a way to “bake” fossils by putting the work of tens of thousands years into a single day.

Known as sediment-encased maturation, the method works by pressing samples into clay tablets and then baking them at 3500 psi. That process — which has been tested on feathers, lizards, and leaves — creates samples that both look and act like real fossils.

That is significant because scientists believe they may be able to use the maturation to study what materials are able to survive fossilization. It may also identify structures within fossils and show what temperatures or gases contributed to them.

“Our experimental method is like a cheat sheet,” said lead author Evan Saitta, a researcher at the University of Bristol, in a statement. “If we use this to find out what kinds of biomolecules can withstand the pressure and heat of fossilization, then we know what to look for in real fossils.”

The study is published in the journal Paleontology.

Categories
Geology NWT_Biology TECH

Microorganisms created tiny tunnels inside garnet, study reports

Microscopic tunnels uncovered inside garnet crystals from Thailand likely came from microorganisms, a new study published in the journal PLOS ONE reports.

This study first came about after a team of international researchers discovered a series of strange tunnels deep within garnet crystals taken from river sediments and soils in Thailand. Though they first wrote off the strange passages, further analysis showed that they could have been created by endolithic organisms.

Such creatures live inside a substrate, including mineral, wood, or bone, and tunnel through it. Though some microbes already exist within cavities, others must dig their way in. That digging process has been recorded many times throughout history, but never in a durable mineral like garnet.

“The reported tunnel system in garnets represents a new endolithic habitat in a hard silicate mineral otherwise known to be resistant to abrasion and chemical attack,” said lead author Magnus Ivarsson, a geobiologist at the Swedish Museum of Natural History, according to Phys.org.

As a result, the team took a close look at the stone to see if the corridors formed through an abiotic or biotic processes.

That study showed the tunnels had lingering organic compounds and filament-like structures, suggesting microbes once lived there.

However, even with that information the team is not sure what made the tunnels. That is because, while the passages have certain abiotic characteristics, they have various endolithic features as well. For example, there is a series of connecting tunnels, which shows that microbes at least played a part in the tunneling process.

While researchers only first took notice of the tunnels because they significantly decrease the quality and value of the garnet, they are not important because they show a never-before-seen habitat for endolithic organisms.

Even so, as compelling as the findings are, they are far from conclusive. More research needs to be done on the stone to see if any more information can be gathered moving forward.  

“There’s definitely work to be done,” added Ivarsson, according to The New York Times.

Categories
Geology NWT_Climate Science

Unique mineral could help combat global warming

A group of researchers from Trent University have discovered a way to quickly produce a carbon-dioxide-storing mineral known as magnesite; a finding that could have large implications in the battle against climate change.

Currently, many scientific teams around the world are working on ways to remove carbon dioxide from the atmosphere. However, there are many issues with developing such technology. Not only are most proposed methods impractical, but they are also extremely costly.  

This new study — which is the first time researchers have been able to explain how magnesite forms at a low temperature — provides a potential answer to such issues.

That is because, as magnesite actively stores CO2, researchers could potentially use it to take the substance out of the atmosphere and counter its warming effect.

To do that, the team behind the research found out how to dramatically accelerate magnesite’s crystallization process.

“Our work shows two things,” said project leader, Ian Power, a professor at Trent University, according to Phys.org.  “Firstly, we have explained how and how fast magnesite forms naturally. This is a process which takes hundreds to thousands of years in nature at Earth’s surface. The second thing we have done is to demonstrate a pathway which speeds this process up dramatically”

By using polystyrene microspheres as a catalyst, the team created magnesite in just 72 days. That is not only much faster than natural processes, but it also leaves the microspheres unchanged so they can be reused at a later date.

The crystallization process occurs at room temperature as well, which means producing the substance is quite energy efficient.  

Though there is still a long way to go in this process, the team is hopeful that magnesite could help reduce the amount of CO2 in Earth’s atmosphere and one day work to cool our planet down.

“For now, we recognise that this is an experimental process, and will need to be scaled up before we can be sure that magnesite can be used in carbon sequestration (taking CO2 from the atmosphere and permanently storing it as magnesite),” added Power, according to The Independent. “This depends on several variables, including the price of carbon and the refinement of the sequestration technology, but we now know that the science makes it doable.”

This work was presented at the Goldschmidt conference in Boston.

Categories
Geology NWT_Climate

Study reveals Greenland’s distant geological past

A relatively warm layer of bedrock hiding beneath Greenland shows the island is much hotter than previously thought, a new study in the journal Geophysical Research Letters reports.

This discovery — which comes from scientists from NASA and the British Antarctic Survey  — shows that the massive island moved over a hotspot of upwelling molten rock tens of millions of years ago during its shift towards the Arctic.

Not only does Greenland still have the scar from the event, but the hotspot that burned it is the same one currently adding more volcanic mass onto Iceland.

Researchers uncovered the new findings by generating a map of “geothermal heat flux” that reveals the variation of warmth that comes out of the Earth’s interior.

That is important because, not only does it provide information on how the Earth’s outer crust shifted over time, but it also could help scientists get a much better idea of how the way Greenland’s iceland sheet will change in the future.

The site is the second largest store of frozen water on Earth, and warming temperatures cause it to lose roughly 280 billion tons of water each year.

While climate models suggest the melting will get worse as the years go on, the ice’s stability largely depends on how hot the bedrock is beneath it. As the bedrock is warmer than past predictions, the ice is likely much less stable as well.

“We expected things to be uniform,” explained lead author Yasmina Martos, a researcher from Nasa’s Goddard Space Flight Center, according to BBC News“But when we saw this track crossing Greenland, we thought, ‘wow – this means something’.”

Analyzing that track of warmth is important, and the team plans to take a closer look at it in the coming months. That will show, not just how Greenland is currently being affected by climate change, but how it may change as times goes on. 

“I don’t think there is any other place on Earth where a plume history has been recorded by a piece of continent that hasn’t been affected by it at the surface,” added Martos, in a statement. “But it’s there, so we can use thermal heat to understand the history of the region.”

Categories
Geology NWT_Earth

The Bronze Age may have been the advent of humanity’s impact on the environment

According to a study published in Science Advances, humans were leaving a noticeable impact on the environment as far back as the Bronze Age, over 2,000 years ago. The research reveals that Bronze Age farmers in Ireland changed the chemistry of the soil they farmed all those years ago, indicating that anthropologists may need to redefine the boundaries of the anthropocene, writes Jessica Boddy for Gizmodo. The researchers found that these Bronze Age farmers began fertilizing their fields with nitrogen-rich manure ensuring a bountiful harvest, but also changing the nitrogen makeup of their fields. “Nitrogen is part of every ecosystem, and it’s a building block of life,” explains Eric Guiry, lead author of the study. “Being able to manage it is key for expanding society.”

As populations grew, Irish farmers fertilized their soil more often and on a larger scale precipitating an increase in a certain nitrogen isotope to show up in animal bones from the middle and late Bronze Age. As Sarah McClure, a zooarchaeologist at Penn State University explains it, “In the Bronze Age, you get these prolonged, deep shifts in the nitrogen composition of the soils due to human activity that never really go away.” In fact, the research team was able to extract the isotope, nitrogen-15, from 712 animal bones from 90 different archaeological sites in Ireland spanning the entire Holocene (the last 10,000 years), Boddy writes.

The nitrogen-15 signatures jumped to levels similar to what is observed now in the modern era, showing that, similar to society today, ancient humans were altering Earth’s environment for their benefit instead of just living in it. “People argue what we do today has no effect with seven billion of us,” Fiona Beglane, a zooarchaeologist and one of Guiry’s co-authors, told Gizmodo. “Now we’re showing people back in the Bronze Age made irreversible changes happen, and there were just a few million people then.”

Categories
Geology Science TECH_Technology

AI could help pinpoint earthquake aftershocks

New advancements in artificial intelligence could help scientists better predict earthquakes, according to a new study published in the journal Nature. 

For years, researchers have tried to find ways to model aftershocks to gain more insight into earthquakes. Though they can predict when aftershocks will occur with decent accuracy, they are far off from properly predicting their location.

The new technology — developed by both Google and researchers at Harvard University — helps with that issue. It is a neural network that uses the same AI that powers Facebook photo tagging to predict where future aftershocks will occur.

To test the system, scientists ran it on a database of 131,000 earthquakes and their aftershock locations. That allowed the AI to match up different patterns. Just as how facial recognition uses pixel arrangements that represent a person’s face, it uses equations to pinpoint aftershock locations.

“There are three things you want to know about earthquakes,” said study co-author Brendan Meade, a researcher at Harvard University, according to The Verge. “When they are going to occur, how big they’re going to be and where they’re going to be. Prior to this work we had empirical laws for when they would occur and how big they were going to be, and now we’re working the third leg, where they might occur.”

The team states the reason the new algorithm is because it uses complex metrics —  maximum shear stress change and the von-Mises yield criterion — that had not previously been thought to be correlated with aftershocks. Such metrics are commonly applied in the sciences of bendable metals, but this finding shows a new potential application.

While there is still a long way to go, the team plans to continue their study. They know they are on the right track and hope the new AI will help bring earthquake predictions to a new level. 

“We’re quite far away from having this be useful in any operational sense at all,” lead author Phoebe DeVries, a researcher at Harvard University, told BBC News. “We view this as a very motivating first step.”

Categories
Archaeology Geology NWT_Earth

Geologists determine new classification of our time in Earth’s history

Geologists divide the 4.6-billion-year existence of Earth into slices of time. Each slice corresponds to significant occurrences in Earth’s history, like dramatic shifts in climate, the emergence of different species of animals and plant life, or the break-up of continents. Now, scientists have announced a new age in Earth’s history spanning the last 4,200 year, reports Jonathan Amos for BBC News. They are calling it the Meghalayan Age, which began with a mega-drought that severely impacted a number of civilizations worldwide.

Though it has been established that we live in the Holocene Epoch—reflecting everything that has happened over the past 11,700 years—according to the International Commission on Stratigraphy (ICS), this epoch can be subdivided. It has proposed three stages be introduced to denote the epoch’s upper, middle and lower phases. To win a classification, a geological time slice has to reflect something whose effects were global in extent, and associated with a rock or sediment type that is unambiguous, Amos explains. The Meghalayan is the youngest stage, and began with a destructive drought whose effects lasted two centuries, crushing civilizations in Egypt, Greece, Syria, Palestine, Mesopotamia, the Indus Valley, and the Yangtze River Valley, writes Amos.

Scientists note that there was a spike in isotopes of oxygen atoms present in the layers of stalagmite found in Mawmluh Cave in Meghalaya, India. “The isotopic shift reflects a 20-30% decrease in monsoon rainfall,” explained Professor Mike Walker of the University of Wales, who led the international team that developed the division proposal. “The two most prominent shifts occur at about 4,300 and 4,100 years before present, so the mid-point between the two would be about 4,200 years before present, and this is the age that we attribute to the [Meghalayan golden spike],” he told BBC News. Despite some scientists’ objection to the classification being decided upon and set in stone (there are those who believe there is still active debate about assigning an age to reflect the influence of humans on the planet), Professor Walker sees no conflict between the new subdivisions, and a “future designation of the Anthropocene.”

Categories
Geology NWT_Earth

Blue diamonds form deep beneath the Earth, study reports

Scientists from the Royal Ontario Museum believe they have found the answer to how rare blue diamonds form, a new study published in the journal Nature reports.

Blue diamonds are some of the rarest gems on Earth. Scientists know that they formed billions of years ago, but they have never been able to determine exactly how that formation process took place.

The stones’ blue tint comes from traces of boron inside the diamond. However, that element is commonly found near the Earth’s surface, not deep below where diamonds form.

To get a closer look at the stones, the team in the study analyzed 46 blue diamonds and examined their imperfections.

“The origin of blue diamonds is such an alluring question — you don’t see them very often,” said study co-author Kim Tait, a gem expert at the Royal Ontario Museum, according to The Washington Post. “And the famous ones, like the Hope Diamond, have such mystique.”

Blue diamonds are rare. So rare, that only 1 in 200,000 are blue. They come from intense pressure deep inside the Earth, but as they form they can trap tiny bits of rock inside them.

Using lasers, researchers searched the diamonds’ for such imperfections and analyzed how the light reflected to see what they contained. That then showed what rocks they formed next to.

Such research revealed that blue diamonds form much deeper down than other diamonds. As a result, it is likely that the Earth’s plates pushed the boron in the ocean floor down into the Earth where it absorbed into the diamonds.

“Most of the impurities contained in these blue diamonds came from a very deep source,” said Dongzhou Zhang, a scientist at the University of Hawaii who was not involved in the study, according to The New York Times. “This study tells us for the first time that blue diamonds are formed very deep in the interior of Earth.”