Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Salt holds samples of ancient seas


Calcium content of ancient water hints at origins of shelled life.
© Corbis

Water trapped for millions of years gives a glimpse of oceans’ turbulent past.

Drops of sea water entombed within salt crystals millions of years ago are giving researchers a glimpse of ancient oceans. The water, trapped during evaporation, reveals that the seas have seen large chemical changes during their history.

"The consensus had been that sea-water chemistry hadn’t changed that much over the past 600 million years," says geochemist Juske Horita of Oak Ridge National Laboratory, Tennessee. The trapped drops are the "first strong evidence" to the contrary, he says.

Geologist Tim Lowenstein, of the State University of New York, Binghamton, and his colleagues gathered crystals from rock salt deposits, froze them and sliced them open. Using X-rays, they probed the chemical composition of water pockets as small as 30 micrometres across - one third of the width of a human hair1.

Crystals from Australia, the Middle East and the Americas, spanning the past 550 million years, suggest that the ratio of calcium to magnesium in sea water has fluctuated by a factor of more than five.

This record needs to be read with care, cautions geologist Robert Goldstein, of the University of Kansas. Salt crystals form only in unusual environments such as lagoons. To translate the droplets into an accurate reflection of the ocean of the time requires "many, many assumptions", Goldstein says.

Despite these drawbacks, Horita believes that "it is probably the best geological record we have right now".

Drop in the ocean

The challenge now is to match the mooted changes in sea-water chemistry with the geological forces that might have caused them. Possible suspects include underwater volcanoes and earthquakes.

When sea-floor plates move apart they release calcium into the water. Lowenstein’s team found that calcium-rich sea water tended to come from periods of ocean-floor spreading.

"It’s a neat picture," says Goldstein. But it’s not complete. Minerals washed off the land by rivers also influence ocean chemistry, as does the atmosphere, he points out.

Recreating how atmosphere, Earth and ocean interacted in the past should help us predict how ocean chemistry will respond to future forces such as rising levels of greenhouse gases. But, warns Goldstein, the final story "will be a lot more complicated than we could ever have imagined".

Life also plays its part. Animals remove large amounts of calcium - a key component of shells and skeletons - from the ocean. Lowenstein’s team saw a large rise in the amount of calcium in the ocean around the time of the Cambrian Explosion.

"This is the period about 540 million years ago when the major animal groups appear in the fossil record. Rising calcium may have stimulated the origin of shelled organisms", Lowenstein speculates.

  1. Lowenstein, T. K. et al. Oscillation in Phanerozoic seawater chemistry: evidence from fluid inclusions. Science, 294, 1086 - 1088, (2001).

JOHN WHITFIELD | Nature News Service
Further information:

More articles from Earth Sciences:

nachricht Gas hydrate research: Advanced knowledge and new technologies
23.03.2018 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ

nachricht New technologies and computing power to help strengthen population data
22.03.2018 | University of Southampton

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Space observation with radar to secure Germany's space infrastructure

Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.

The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...

Im Focus: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

New solar solutions for sustainable buildings and cities

23.03.2018 | Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

Latest News

For graphite pellets, just add elbow grease

23.03.2018 | Materials Sciences

Unique communication strategy discovered in stem cell pathway controlling plant growth

23.03.2018 | Agricultural and Forestry Science

Sharpening the X-ray view of the nanocosm

23.03.2018 | Physics and Astronomy

Science & Research
Overview of more VideoLinks >>>