. Earth Science News .
EARLY EARTH
Ancient rocks reveal how Earth recovered from mass extinction
by Staff Writers
Edinburgh UK (SPX) Jul 21, 2016


illustration only

Scientists have shed light on why life on Earth took millions of years to recover from the greatest mass extinction of all time.

The study provides fresh insight into how Earth's oceans became starved of oxygen in the wake of the event 252 million years ago, delaying the recovery of life by five million years.

Findings from the study are helping scientists to better understand how environmental change can have disastrous consequences for life on Earth.

The Permian-Triassic Boundary extinction wiped out more than 90 per cent of marine life and around two thirds of animals living on land. During the recovery period, Earth's oceans became starved of oxygen - conditions known as anoxia.

Previous research suggested the mass extinction and delayed recovery were linked to the presence of anoxic waters that also contained high levels of harmful compounds known as sulphides.

However, researchers say anoxic conditions at the time were more complex, and that this toxic, sulphide-rich state was not present throughout all the world's oceans.

The team, led by researchers at the University of Edinburgh, used precise chemical techniques to analyse rocks unearthed in Oman that were formed in an ancient ocean around the time of the extinction.

Data from six sampling sites, spanning shallow regions to the deeper ocean, reveal that while the water was lacking in oxygen, toxic sulphide was not present. Instead, the waters were rich in iron.

The finding suggests that iron-rich, low oxygen waters were a major cause of the delayed recovery of marine life following the mass extinction.

The study also shows how oxygen levels varied at different depths in the ocean. While low oxygen levels were present at some depths and restricted the recovery of marine life, shallower waters contained oxygen for short periods, briefly supporting diverse forms of life.

The precise cause of the long recovery period remains unclear, but increased run-off from erosion of rocks on land - caused by high global temperatures - likely triggered anoxic conditions in the oceans, researchers say.

The study, published in the journal Nature Communications, was funded by the Natural Environment Research Council and the International Centre for Carbonate Reservoirs. The work is a contribution to the UNESCO International Geoscience Programme. It was carried out in collaboration with the Universities of Leeds, Gratz, Bremen and Vienna University.

Dr Matthew Clarkson, of the University of Edinburgh's School of GeoSciences, who led the study, said: "We knew that lack of oxygen in the oceans played a key role in the extinction and recovery processes, but we are still discovering how exactly it was involved. Our findings about the chemistry of the ocean at the time provide us with a clearer picture of how this complex process delayed the recovery of life for so long."

Professor Simon Poulton, of the University of Leeds, who co-authored the study, said: "The neat point about this study is that it shows just how critical an absence of oxygen, rather than the presence of toxic sulphide, was to the survival of animal life. We found that marine organisms were able to rapidly recolonise areas where oxygen became available."


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only


.


Related Links
University of Edinburgh
Explore The Early Earth at TerraDaily.com






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Previous Report
EARLY EARTH
The success of the plant-eating dinosaurs
Bristol UK (SPX) Jul 19, 2016
There has been a long debate about why dinosaurs were so successful. Say dinosaur, and most people think of the great flesh-eaters such as Tyrannosaurus rex, but the most successful dinosaurs were of course the plant-eaters. A new study from the University of Bristol, led by Masters of Palaeobiology student Eddy Strickson, has presented clear evidence about how plant-eating dinosaurs evolv ... read more


EARLY EARTH
Study: Crumbling school buildings yield crummy scores

Taiwan buses recalled after deadly fire disaster

Ex-Marine 'assassinated' Baton Rouge cops: police

Ex-Marine 'assassinated' Baton Rouge cops

EARLY EARTH
Fallout Fungi From Chernobyl Flee Earth on ISS Radiation Study Mission

NASA to Begin Testing Next Generation of Spacecraft Heat Exchangers

Passive Attitude Control For Small Satellites

Active tracking of astronaut rad-exposures targeted

EARLY EARTH
Massive sewage spill forces closure of Los Angeles beaches

South Africa's great white sharks face extinction: study

Ocean acidification - the limits of adaptation

Ocean Glider tells quite a tale after 74 days at sea

EARLY EARTH
Warming Arctic could disrupt migration patterns of millions of birds

More Chinese vessels to sail the Arctic: shipping firm

NASA's Field Campaign Investigates Arctic North American Ecosystems

Ocean warming to blame for Antarctic Peninsula glacier retreat

EARLY EARTH
ANU leads effort to develop drought-proof crops

More for less in pastures

How plants can grow on salt-affected soils

Scientists sequence genome of 6,000-year-old barley

EARLY EARTH
Tokyo jolted by third quake in four days

Tropical Storm Frank forms in Pacific off Mexico: NHC

Tide-triggered tremors give clues for earthquake prediction

Super-eruptions may give a year's warning before they blow

EARLY EARTH
Armed group kills 17 soldiers at Mali base: ministry

Mali opens terrorism inquiry after 17 soldiers killed

Bashir reshuffles senior Sudanese military officials: army

Low uptake of space technology science slows Africa's growth: experts

EARLY EARTH
Cave art reveals religious encounters between Europeans and Native Americans

Technological and cultural innovations amongst early humans not sparked by climate change

Genomes from Zagros mountains reveal different Neolithic ancestry

Changes in primate teeth linked to rise of monkeys









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.