Smallest Ancient Seawater Bags Ever Revealed – Is It Up To Speed With That?

news7g11/21/2022

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Smallest Ancient Seawater Bags Ever Revealed - Is It Up To Speed With That?

The discovery could open a whole new chapter in climate science and help identify subsurface sites to safely store hydrogen for carbon-free energy.

A peer-reviewed publication

DOE/NOW PACIFIC NATIONAL LABOR

Ancient pockets of seawater trapped in an iron pyrite framboite, shown here, provide a new source of clues about climate change in the vanished oceans and our own.

RICHLAND, Wash.—Strapped for millennia, the tiniest liquid remnant of an ancient inland sea is now revealed. The surprising discovery of seawater sealed in what is now North America for 390 million years opens a new avenue to understand how the oceans change and adapt to climate change. The method could also be useful in understanding how hydrogen can be safely stored underground and transported for use as a carbon-free fuel source.

“We discovered that we can actually extract information from these mineral features that could help inform geological studies, such as the chemical composition of seawater from the earliest times. ancient,” said Sandra TaylorThe study’s first author and scientist at the Department of Energy Pacific Northwest National Laboratory.

Taylor worked with colleagues PNNL Daniel Perea, John the cliffand Libor Kovarik to perform the analyzes in collaboration with geochemists Daniel Gregory of the University of Toronto and Timothy Lyons of the University of California, Riverside. researchers reported their discovery in the December 2022 issue of the journal Letters of Earth and Planetary Science.

ancient sea; modern tools

Many minerals and gems contain small pockets of trapped fluid. Indeed, some gemstones are prized for their luminous liquid bubbles within. What’s different about this study is that scientists were able to reveal what’s inside the tiniest pockets of water, using advanced microscopy and chemical analysis.

The study’s findings confirm that the water trapped inside the rock is consistent with the chemical composition of the ancient inland saltwater sea that once occupied upstate New York, where the rock formed. During the Middle Devonian period, this inland sea stretched from present-day Michigan to Ontario, Canada. It contains a reef that rivals Australia’s Great Barrier Reef. Sea scorpions the size of a pickup truck patrol waters containing now-extinct creatures like trilobites and the earliest examples of horseshoe crabs.

But eventually the climate changed, and with that change, most of the living things and the sea itself disappeared, leaving only fossil remains that lay in the sediments that eventually became pyrite samples. used in the present experiment.

Clues to Ancient Climate and Climate Change

Scientists use rock samples as evidence to piece together how the climate has changed over a geologically long period of time.

“We used mineral deposits to estimate the temperature of the ancient oceans,” said Gregory, a geologist at the University of Toronto and one of the study’s leaders. But there are relatively few useful examples in the geological record.

“Salt deposits from trapped seawater [halite] relatively rare in the rock record, so there are millions of years missing from the record and what we know today is based on a few localities where halite was found,” says Gregory. In contrast, pyrite is found everywhere. “Sampling using this technique could open up the geological record of millions of years and lead to new insights into climate change.”

Unexpected sea water

The team was trying to understand another environmental problem—toxic arsenic leaking from rocks—when they noticed minor imperfections. Scientists describe the appearance of these particular pyrite minerals as framboites—from the French word for raspberries—because they look like clusters of raspberry segments under a microscope. Because.

“We first looked at these samples through an electron microscope and we saw these kinds of tiny bubbles or small features inside the frame and wondered what they were,” says Taylor.

Using the precise and sensitive detection techniques of atomic probe tomography and mass spectrometry—which can detect extremely small amounts of elements or impurities in minerals—the team discovered discovered that the bubbles actually contained water and that their salt chemistry was consistent with ancient seas.

From ancient seas to modern energy storage

These types of studies also have the potential to provide interesting insights into how to safely store hydrogen or other gases underground.

“Hydrogen is being explored as a low-carbon fuel source for various energy applications. This requires being able to safely capture and store large amounts of hydrogen in underground geological reservoirs. So it’s important to understand how hydrogen interacts with rock,” Taylor said. “Atomic probe tomography is one of the few techniques where you can not only measure hydrogen atoms, but can actually see where it goes in a mineral. This study suggests that small defects in minerals can be potential traps for hydrogen. So using this technique we can figure out what’s going on at the atomic level, which will then help evaluate and optimize strategies for storing hydrogen below the surface.”

This study was conducted at EMSL, the agency Environmental Molecular Science Laboratory, a user base of the DOE Office of Science at PNNL. Lyons and Gregory apply to use the facility through a competitive application process. The research was also supported by a grant from the Engineering and Natural Sciences Research Council of Canada.