Featured Research

from universities, journals, and other organizations

Mining ancient ores for clues to early life

Date:
December 10, 2012
Source:
McGill University
Summary:
An analysis of sulfide ore deposits from one of the world's richest base-metal mines confirms oxygen levels were extremely low on Earth 2.7 billion years ago, but also shows that microbes were actively feeding on sulfate in the ocean and influencing seawater chemistry during that geological period. The research provides new insight into how ancient metal-ore deposits can be used to better understand the chemistry of the ancient oceans -- and the early evolution of life.

Scientists probe Canadian sulfide ore to confirm microbial activity in seawater 2.7 billion years ago.
Credit: Image courtesy of McGill University

An analysis of sulfide ore deposits from one of the world's richest base-metal mines confirms that oxygen levels were extremely low on Earth 2.7 billion years ago, but also shows that microbes were actively feeding on sulfate in the ocean and influencing seawater chemistry during that geological time period.

Related Articles


The research, reported by a team of Canadian and U.S. scientists in Nature Geoscience, provides new insight into how ancient metal-ore deposits can be used to better understand the chemistry of the ancient oceans -- and the early evolution of life.

Sulfate is the second most abundant dissolved ion in the oceans today. It comes from the "rusting" of rocks by atmospheric oxygen, which creates sulfate through chemical reactions with pyrite, the iron sulfide material known as "fool's gold."

The researchers, led by PhD student John Jamieson of the University of Ottawa and Prof. Boswell Wing of McGill, measured the "weight" of sulfur in samples of massive sulfide ore from the Kidd Creek copper-zinc mine in Timmins, Ontario, using a highly sensitive instrument known as a mass spectrometer. The weight is determined by the different amounts of isotopes of sulfur in a sample, and the abundance of different isotopes indicates how much seawater sulfate was incorporated into the massive sulfide ore that formed at the bottom of ancient oceans. That ancient ore is now found on Earth's surface, and is particularly common in the Canadian shield.

The scientists found that much less sulfate was incorporated into the 2.7 billion-year-old ore at Kidd Creek than is incorporated into similar ore forming at the bottom of oceans today. From these measurements, the researchers were able to model how much sulfate must have been present in the ancient seawater. Their conclusion: sulfate levels were about 350 times lower than in today's ocean. Though they were extremely low, sulfate levels in the ancient ocean still supported an active global population of microbes that use sulfate to gain energy from organic carbon.

"The sulfide ore deposits that we looked at are widespread on Earth, with Canada and Quebec holding the majority of them," says Wing, an associate professor in McGill's Department of Earth and Planetary Science. "We now have a tool for probing when and where these microbes actually came into global prominence."

"Deep within a copper-zinc mine in northern Ontario that was once a volcanically active ancient seafloor may not be the most intuitive place one would think to look for clues into the conditions in which the earliest microbes thrived over 2.7 billion years ago," Jamieson adds. "However, our increasing understanding of these ancient environments and our abilities to analyze samples to a very high precision has opened the door to further our understanding of the conditions under which life evolved."

The other members of the research team were Prof. James Farquhar of the University of Maryland and Prof. Mark D. Hannington of the University of Ottawa.

The Natural Sciences and Engineering Research Council of Canada made this study possible through fellowships to Jamieson and a Discovery grant to Wing.


Story Source:

The above story is based on materials provided by McGill University. Note: Materials may be edited for content and length.


Journal Reference:

  1. J. W. Jamieson, B. A. Wing, J. Farquhar, M. D. Hannington. Neoarchaean seawater sulphate concentrations from sulphur isotopes in massive sulphide ore. Nature Geoscience, 2012; DOI: 10.1038/ngeo1647

Cite This Page:

McGill University. "Mining ancient ores for clues to early life." ScienceDaily. ScienceDaily, 10 December 2012. <www.sciencedaily.com/releases/2012/12/121210133500.htm>.
McGill University. (2012, December 10). Mining ancient ores for clues to early life. ScienceDaily. Retrieved February 1, 2015 from www.sciencedaily.com/releases/2012/12/121210133500.htm
McGill University. "Mining ancient ores for clues to early life." ScienceDaily. www.sciencedaily.com/releases/2012/12/121210133500.htm (accessed February 1, 2015).

Share This


More From ScienceDaily



More Fossils & Ruins News

Sunday, February 1, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Discovery Of 'Dragon' Dinosaur In China Could Explain Myths

Discovery Of 'Dragon' Dinosaur In China Could Explain Myths

Newsy (Jan. 30, 2015) A long-necked dinosaur from the Jurassic Period was discovered in China. Researchers think it could answer mythology questions. Video provided by Newsy
Powered by NewsLook.com
Battle of Waterloo Artefacts Go on Display at Windsor Castle

Battle of Waterloo Artefacts Go on Display at Windsor Castle

AFP (Jan. 29, 2015) Artefacts from the Battle of Waterloo go on display at Windsor Castle to mark the 200th anniversary of the momentous battle. The exhibition includes contemporary prints, drawings and personal belongings of French Emperor Napoleon. Duration: 00:31 Video provided by AFP
Powered by NewsLook.com
Mideast Skull Find Sheds Light on Human Ancestors' Trek

Mideast Skull Find Sheds Light on Human Ancestors' Trek

AFP (Jan. 29, 2015) A 55,000-year-old partial skull found in the Middle East gives clues to when our ancestors left their African homeland, and strengthens theories that they co-habited with Neanderthals. Duration: 00:54 Video provided by AFP
Powered by NewsLook.com
Scientists Say Earliest Snakes Lived Alongside The Dinosaurs

Scientists Say Earliest Snakes Lived Alongside The Dinosaurs

Newsy (Jan. 28, 2015) Wrongly categorized as lizard fossils, snake fossils now show the reptile could have developed earlier than we thought — 70 million years earlier. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins