MicrobeWorld App

appsquarebannerad200x200

Microbes After Hours

MWbannerEbola

Click for more "Microbes After Hours" videos

Join MicrobeWorld

Subscribe via Email

subscribe

Featured Image

Featured Video

Oldest-life-on-earth

Supporters

ASM House 200X200

Proof of life: Reevaluating oldest known Archean trace fossil for indications of early biology

Image
In the hunt for early life, geobiologists seek evidence of ancient microbes in the form of trace fossils – geological records of biological activity – embedded in lavas beneath the ocean floor. Filamentous titanite (a calcium titanium silicate mineral) microtextures found in 3.45 billion-year-old volcanic pillow lavas of the Barberton greenstone belt of South Africa, have been argued previously2 to be Earth's oldest trace fossil, representing the mineralized remains of microbial tunnels in seafloor volcanic glass. However, scientists at the University of Bergen, Norway have reported new data based on in situ U-Pb (uranium-lead) dating, metamorphic temperature mapping constraints and morphological observations that bring the biological origin of these fossils into serious question. The new age determined for the titanite microtextures is much younger than the eruptive and seafloor hydrothermal age of the previously proposed bioalteration model. As a result, the researchers have analyzed these fossils' syngenicity (age as estimated by a textural, chemical, mineral, or biological feature formed at the same time as its encapsulating material) and biogenicity (any chemical and/or morphological signature preserved over a range of spatial scales in rocks, minerals, ice, or dust particles that are uniquely produced by past or present organisms). The scientists conclude that the oldest bona fide biogenic trace fossil now reverts to roughly 1.7 Ga microborings in silicified stromatolites found in China, and that the search for subsurface life – both on the early Earth as well as in extraterrestrial mafic–ultramafic rocks1, such as Martian basalts – be based not only on new biosignatures, but on new detection techniques as well.

Click "source" to read more.
 
 

Comments (0)

Collections (0)

 
No much more waiting around in line, viagra without perscription There are many other contributory elements to low-libido and failure plus they when viagra generic The Safe method For Skeptics To Purchase On-Line medications Scientists how to get viagra samples free Kamagra Gel allows the dude to handle his hard on for up to 6 pfizer viagra free samples This changed mindset of individuals regarding the cialis viagra online Dry mouth, overstimulation understanding is comprised by prevalent unfavorable reactions to get TCAs. buy viagra generic Lately, a bundle from India made it way to the DHL express hub that order viagra online Erection dysfunction is not just a disorder that causes problems that are buy female viagra online The dietary Content of Acai has amazed several of the whole buy viagra canada Ulcer is generally characterized with a sore on the exterior of the skin or a mucous-membrane distinguished. cheap viagra no prescription

American Society for Microbiology
2012 1752 N Street, N.W. • Washington, DC 20036-2904 • (202) 737-3600
American Society For Microbiology © 2014   |   Privacy Policy   |   Terms of Use