Researchers from the "University of Utah" (UNIVERSITY OF UTAH) found a new method for preserving rare magnetic fossils for scientific analysis without the need to grind them into a fine powder.
The information in magnetic fossils is helping scientists understand how oceans have responded to past climate changes, and how our current ocean can respond to continual warming.
Magnetic fossils
Magnetic fossils (magnetofossil) are microscopic iron bacterial fossils, made by a specific type of bacteria called "magnetic bacteria". There are no known organisms that make up giant magnetic fossils today;
So they are very valuable fossils that should not be crushed every time scientists want to use them in a specific research.
These fossils are found in ancient marine sediments, and are composed of a small number of magnetic nanoparticles, and these fossils are distinguished by their ability to tell us a lot about the climate in the past, especially cases of sudden global warming.
The results of the new research and the new method of collecting valuable information in these fossils - by both PhD student Courtney Wagner and Peter Liebert, assistant professor at the University of Utah - were published in the journal Proceedings of the National Academy of Sciences (PNAS) in February 2021. .
"It is very interesting to be part of a discovery like this, which is something that other researchers studying magnetic fossils and periods of planetary change can use," Wagner said in the press release published by the university. "This work could be used by many other scientists, inside and outside." Our specialized community. This is very exciting and beneficial. "
Electron microscope images of giant magnetic needles, which have a cylindrical shape, and some of them roll towards one end of the crystal (Uric Allert)
Magnetic bacteria
Magnetic bacteria create magnetic particles about one thousandth of a hair's width, which when assembled into a chain inside the cell act like a nanoscale compass.
These bacteria can then use this compass to align the Earth's magnetic field and travel efficiently to their preferred chemical conditions within the water.
During the last few periods of Earth's history, specifically in the beginning and middle of the Eocene epoch, from 56 to 34 million years ago, some of these biologically produced magnets grew to "gigantic" sizes, about 20 times larger than the typical magnetic fossils, and they also grew. In odd shapes like needles, spearheads, and giant bullets.
Because these bacteria used their superior magnetic sense to find better levels of food and oxygen in ocean waters, and because giant magnetic fossils are associated with periods of rapid climate change and global warming;
So it carries a lot of information about ocean conditions during periods of rapid warming, especially how those conditions change over time.
The organisms that produced these giant magnetic fossils in the past are completely mysterious (Banas - University of Utah)
Sample extraction
Previously, extracting and analyzing these fossils required grinding samples into a fine powder for electron microscopy.
Wagner says, "The extraction process can take a long time and may not succeed, and electron microscopy can be costly. In addition, destroying the samples means that they are no longer useful for most other experiments."
In addition to "collecting and storing these samples requires specialized personnel and specific equipment, we want to keep as much material as possible for further studies";
So in this study, the researchers discovered another way to do this, using sediment samples collected in New Jersey, and they designed a new method to perform an analysis called FORC measurements.
Using these high-resolution magnetic measurements, they found that the magnetic signature of the giant magnetic fossils was distinctive enough to use this technique in other samples to determine the presence of the fossils.
Egley says, "Fork's measurements verify the interaction of magnetic particles with externally applied magnetic fields, which allows distinguishing between different types of iron oxide particles without actually seeing them."
The researchers say, "The ability to find groups of giant magnetic fossils in the geological record helps determine the origin of these unusual magnetic fossils," in addition to the environment of the organisms that formed these fossils.
Wagner says this is important because there are no known organisms that make up giant magnetic fossils today, and we still don't know what organisms formed them in the past.
The organisms that produced these gigantic magnetic fossils are completely mysterious, but this leaves exciting fields of research open for the future.