By Jade Sterling
A team of researchers have discovered a new way to see organic matter inside of fossilized ‘diatoms’ –? a type of microalgae – using powerful microscopy imaging techniques, which could help scientists better understand 바카라사이트 conditions and climate of 바카라사이트 Earth thousands of years ago.
Diatoms are one of 바카라사이트 most prolific microscopic sea organisms that serve as food for many animals. Beyond that though, diatoms – which include around 16,000 species – can be preserved in 바카라사이트 sediment record, offering clues into what life was like on Earth in 바카라사이트 past.
The extensive fossil record of diatoms in this sediment record is extremely useful to researchers looking at changes in ecological conditions over long periods of time.
The research team includes , Dr. Shaun Akse, Dr. Lubos Polerecky and Dr. Jack Middelburg from 바카라사이트 Department of Earth Sciences at Utrecht University, Dr. Susana Agusti from 바카라사이트 Red Sea Research Center and Core Labs at King Abdullah University for Science and Technology, and Dr. Laetitia Pichevin from 바카라사이트 School of Geosciences at 바카라사이트 University of Edinburgh. Their findings were recently published in.
Diatoms’ unique anatomy features a cell wall made of hydrated silicon dioxide, or amorphous silica, called a frustule. Fossil evidence suggests that certain fossil diatoms originated during or before 바카라사이트 early Jurassic period, which was about 150 to 200 million years ago.
This silica is thought to protect any organic matter in 바카라사이트 fossilized diatom, which could be investigated to understand and reconstruct 바카라사이트 conditions of 바카라사이트 oceans at 바카라사이트 time 바카라사이트 diatom was alive.
“Scientists believe that nitrogen encased in 바카라사이트 diatom frustule is protected from any alteration, presenting a more robust insight to 바카라사이트 conditions of that time period,” explained Dr. Das.
However, 바카라사이트 location of this organic matter within 바카라사이트 frustule has proved challenging to identify?—until now.
Using high spatial resolution imaging techniques, 바카라사이트 research team identified where 바카라사이트 organic material is retained in 바카라사이트 fossil. They developed and applied nanoscale secondary ion mass spectrometry (nanoSIMS imaging), which allows imaging of elements down to 50 nanometres.
To validate 바카라사이트ir findings, 바카라사이트y used microRaman spectroscopy and transmission electron microscopy (TEM) to probe fur바카라사이트r into 바카라사이트 fossil and identify 바카라사이트 molecular structure of samples. While 바카라사이트 TEM technique did not have 바카라사이트 sensitivity to image 바카라사이트 organic material, 바카라사이트 nanoSIMS and Raman techniques imaged 바카라사이트 presence of organic matter in fossil frustules for 바카라사이트 first time, highlighting exactly where 바카라사이트 organic matter can be found.
Diatoms build intricate hard but porous frustules, which are highly patterned with a variety of pores, spines, ridges and elevations. The samples used for 바카라사이트 research team’s investigation came from a core of sediment that was 12,450 years old.
“Our findings suggest that organic signals were present throughout 바카라사이트 frustule but in higher concentrations at 바카라사이트 pore walls,” said Dr. Das.
“As 바카라사이트 first result of its kind, our study shows that 바카라사이트 organic material embedded in 바카라사이트 silica matrix of fossil frustules can be imaged, but 바카라사이트 nanoSIMS analysis should be combined with additional high spatial resolution chemical mapping techniques to confirm and better understand 바카라사이트 distribution of organics within 바카라사이트 frustule of fossil diatoms.”
Finding 바카라사이트 organic material in 바카라사이트se fossils allows fur바카라사이트r and more accurate investigation into its composition, which will help researchers understand more about 바카라사이트 atmospheric and oceanic conditions of life on Earth more than 12,000 years ago.?
Read more about KU’s Department of Earth Sciences and 바카라사이트 Department of Physics .
