Navigation Links
Geologists revisit the Great Oxygenation Event
Date:8/19/2010

ig rise in evolution associated with the final oxygen event."

"But then they noticed that after the big rise in spiny cysts and just when we see evidence for oxygen in the rock record, the acritarchs disappear. And that really doesn't make sense if you're evolving new groups because of the increase in oxygen."

"In 2009 a group of scientists led by Phoebe Cohen of Harvard University inspected acritarchs with transmission electron microscopes and concluded that they are not algae but rather animals, encased in protective cysts that animals form when conditions are not favorable to life," says Fike.

At the same time a group of scientists (including Fike) led by Chao Li of the University of California Riverside measured redox proxies in several different sections through the formation.

These measurements showed that the Nanhua Basin had had a layered chemical structure with deep iron-rich waters, near-shore wedges of sulfur-rich water and an oxygenated surface.

Both the sulfur- and the iron-rich waters would have been lethal to oxygen-loving species.

A Cautionary Tale

At the same time Fike acknowledges that spatial variability in redox proxies may make many geologists feel ill at ease because it might instead reflect an unusual depositional context or the reworking of the proxy after deposition instead of a signficant change in geochemistry.

By way of illustration, he describes a study of Amazonian mud belts, published this year by Robert Aller of Stony Brook University and colleagues in Geochimica et Cosmochimica Acta.

"The Amazon dumps mud rich in organic material into the Atlantic," Fike says. "The mud is deposited and the oxygen in it is consumed by biological activity, but then a storm churns it up, it gets reoxygenated, and redeposited. And this process happens over and over again."

By the time the muds become sediments, their chemistry is very different from what it was w
'/>"/>

Contact: Diana Lutz
dlutz@wustl.edu
314-935-5272
Washington University in St. Louis
Source:Eurekalert  

Page: 1 2 3 4 5 6

Related biology news :

1. Brown geologists show unprecedented warming in Lake Tanganyika
2. Geologists studying groundwater arsenic levels in India empower Bengali women, children
3. University of Leicester geologists demonstrate extent of ancient ice age
4. Geologists map rocks to soak CO2 from air
5. 30 years later, what killed the dinosaurs is revisited
6. New research aims to unravel how phosphorus pollution drives toxic algal blooms in the Great Lakes
7. NOAA awards $2.5 million for research on invasive species in the Great Lakes
8. Children born after assisted reproduction at greater risk of congenital malformations
9. Fossil-fuel use and feeding world cause greatest environmental impacts: UNEP panel
10. The great pond experiment: Regional vs. local biodiversity
11. Small mammals -- and rest of food chain -- at greater risk from global warming than thought
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Geologists revisit the Great Oxygenation Event
(Date:8/31/2014)... data from the last 19 years reveals that fresh water ... of Antarctica to rise by 2cm more than the global ... detected the rapid rise in sea-level by studying satellite scans ... kilometres. , The melting of the Antarctic ice ... an excess of around 350 gigatonnes of freshwater to the ...
(Date:8/31/2014)... decades, malaria diagnosis has changed very little. After taking a ... across a glass slide, stains it with a special dye, ... causes the disease. This approach gives an accurate count of ... measure of disease severity but is not ideal because ... from the Singapore-MIT Alliance for Research and Technology (SMART) has ...
(Date:8/29/2014)... some surprising discoveries about the body,s initial responses ... the team found that specialized cells in the ... viral invasion and are the source of gut ... (IL-1β). , Though aimed at the presence ... epithelium that provides a barrier to protect the ...
Breaking Biology News(10 mins):A new way to diagnose malaria 2A new way to diagnose malaria 3The early cost of HIV 2
... Incredible camera trap video footage from the forests ... in that country are paying off, according to the ... traps from several locations across Thailand,s Western Forest Complex ... glimpses into the lives of tigers, Asian elephants, gaurs, ...
... proposed, it was dismissed as being unrealizable: "It,ll never ... research funding. Today, 15 years later, the physicist Professor ... presented with the Deutscher Zukunftspreis, one of Germany,s most ... controversial idea. Leo, director of the Fraunhofer Institute for ...
... an adorable doe-eyed bat with a dark side it is ... a PhD student in ecology and evolutionary biology at The City ... a revolutionary way to help fund her research into how this ... can spread from flying foxes to humans by tracing the evolution ...
Cached Biology News:Candid video clips from Thailand show anti-poaching efforts saving wildlife 2Electronics made of plastic 2Electronics made of plastic 3Electronics made of plastic 4Crowdfunding science: Student raises cash online to follow a flying fox 2Crowdfunding science: Student raises cash online to follow a flying fox 3
(Date:8/31/2014)... N.J. , Aug. 31, 2014 Wockhardt ... Drug Discovery program in Anti-Infective research when two of ... coveted Qualified Infectious Disease Product (QIDP) status from U.S. ... to drugs which act against pathogens which have a ... are identified by Centre for Disease Control (a top ...
(Date:8/31/2014)... Texas (PRWEB) August 31, 2014 ... Polyacrylamide Industryā€¯ is a professional and in-depth ... report provides basic Polyacrylamide information, including Polyacrylamide ... as well as industry overview. This research ... market as well as global industry analysis ...
(Date:8/30/2014)... Dallas, TX (PRWEB) August 31, 2014 ... Industry is a professional and in-depth study on ... industry in Global and China. , The report ... definitions, applications and industry chain structure. Global market ... with a focus on history, developments, trends and ...
(Date:8/29/2014)... but one of the most promising technologies for future ... light (photons) instead of electrons. First, it is necessary ... photons and control their direction. Researchers around the world ... control, but now scientists at the Niels Bohr Institute ... emitted one at a time and in a particular ...
Breaking Biology Technology:U.S. FDA Grants QIDP Status for Wockhardt Anti-Infective Drug Discovery Program 2U.S. FDA Grants QIDP Status for Wockhardt Anti-Infective Drug Discovery Program 3International Polyacrylamide Industry & Copper Iodide Market Data Analysis Now Available at DeepResearchReports.com 2International Polyacrylamide Industry & Copper Iodide Market Data Analysis Now Available at DeepResearchReports.com 3Electrical Insulating Varnish Market World, China Regional Analysis & 2020 Forecasts Available at DeepResearchReports.com 2Electrical Insulating Varnish Market World, China Regional Analysis & 2020 Forecasts Available at DeepResearchReports.com 3Breakthrough in light sources for new quantum technology 2
... The approval of an emergency,contraceptive with over-the-counter access ... option for preventing unintended pregnancy.,However, many patients are ... when they may need it. Clinicians should to ... patients about their,risk of pregnancy., To address ...
... Products for Aida,s ... ... (OTC Bulletin Board: AIDA) today announced that has,acquired one of China,s ... Aida,s subsidiary, Hanzhou,Aida Pharmaceuticals Co., Ltd acquired 43% of the institute ...
... Equity Investment and Line of Credit -, ... Board: MODG), a biopharmaceutical company applying its,patented technology ... announced that it has closed a $2 million,equity ... has entered into a,line of credit agreement that ...
Cached Biology Technology:Publication Addresses Misconceptions About Emergency Contraception 2Aida Acquires High-Level Research Institute in China 2Modigene Announces Closing of $12 Million Financing by Members of The Frost Group 2Modigene Announces Closing of $12 Million Financing by Members of The Frost Group 3Modigene Announces Closing of $12 Million Financing by Members of The Frost Group 4Modigene Announces Closing of $12 Million Financing by Members of The Frost Group 5
Viral CCI Biotinylated Affinity Purified PAb...
Human RXR beta/NR2B2 MAb (Clone H7341) Keywords: RXRbeta, RXRbeta, Retinoid X Receptor beta...
Human SOST Affinity Purified Polyclonal Ab...
BOND ELUT MATRIX-C18, 25 mg ...
Biology Products: