Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Seabed secrets in English clay

26.04.2004


Fossilized organic molecules of green sulfur bacteria are helping to unlock secrets of what may have been a period of helter-skelter climate change and mass kills of sea life during the Jurassic Period some 150-160 million years ago.



The fossils were found in sedimentary rock commonly used to make house bricks in England, quarried from what is called the Oxford Clay Formation.

The findings are reported in the May issue of the journal Geology (now online to subscribers.) Fabien Kenig, associate professor of earth and environmental sciences at the University of Illinois at Chicago, is the article’s lead author. Contributors include John Hudson of the University of Leicester, Jaap Sinninghe Damsté of the Royal Netherlands Institute for Sea Research and Brian Popp of the University of Hawaii.


Kenig and his colleagues have spent almost 15 years trying to learn why the bacteria -- which thrive only in oxygen-free but hydrogen sulfide-rich aquatic environments -- apparently co-existed with ancient, oxygen-breathing sea reptiles and other bottom-dwellers in a shallow part of a sea that’s now the region of east-central England around Peterborough.

"It should have been one or the other," said Kenig. "You can’t have both at the same time. They cannot co-exist."

Using solvents to extract oily lipids from sediments, the geologists identified the signature organic compounds of green sulfur bacteria using gas chromatographs and mass spectrometers.

"Molecules of green sulfur bacteria have a very specific, recognizable pattern or trace that allowed us to identify them in every sample of the Oxford Clay shale that we studied," said Kenig. "We found that their presence was not just an accidental find in a few samples, but corresponds to a recurring, ubiquitous process during deposition of those sediments."

A casual look at a piece of sedimentary rock embedded with fossils suggests a broad-strokes picture of what organisms may have lived in a given epoch of time. Kenig’s samples included seemingly incompatible creatures living together. The standard interpretation of the fossil record needed some refinement.

"The animal fossils and bacteria organic matter, though contained in the same packet of rock, were not deposited at the same time," he said. "There was the deposition of organic matter and clay during one set of environmental conditions, then when conditions changed and became favorable, different organisms colonized the environment and left their remains, some as a result of a mass kill by the next anoxic -- or complete lack of oxygen -- event."

"There are indications that conditions in the Oxford Clay-sea were extremely dynamic at the time, probably in response to climatic changes," said Kenig.

The finding suggests that use of fossils to reconstruct environmental records of the past needs to be interpreted with greater care because details from sedimentary deposits, as Kenig and his colleagues found, suggest that these fossils may only represent end-member environments.


The research was supported by grants from the National Science Foundation and the National Environmental Research Council.

Paul Francuch | EurekAlert!
Further information:
http://www.uic.edu/

More articles from Earth Sciences:

nachricht Six-decade-old space mystery solved with shoebox-sized satellite called a CubeSat
15.12.2017 | National Science Foundation

nachricht NSF-funded researchers find that ice sheet is dynamic and has repeatedly grown and shrunk
15.12.2017 | National Science Foundation

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Engineers program tiny robots to move, think like insects

15.12.2017 | Power and Electrical Engineering

One in 5 materials chemistry papers may be wrong, study suggests

15.12.2017 | Materials Sciences

New antbird species discovered in Peru by LSU ornithologists

15.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>