Quantcast

Latest Proterozoic Stories

f7e934f8a71352427992667d16692ca9
2009-10-03 11:19:54

Princeton University scientists have shown that, in ancient times, the Earth's magnetic field was structured like the two-pole model of today, suggesting that the methods geoscientists use to reconstruct the geography of early land masses on the globe are accurate. The findings may lead to a better understanding of historical continental movement, which relates to changes in climate. By taking a closer look at the 1.1 billion-year-old volcanic rocks on the north shore of Lake Superior, the...

e764dcc605fdfc6b6f29b2fa84fb7d331
2009-07-09 06:00:00

The Earth has experienced many turning points over its 4.5-billion-year history, such as periods of extreme temperature changes, asteroids and the arrival and disappearance of various life forms.  But one of the most monumental events was the Cambrian-era explosion of life some 540 million years ago, when complex, multi-cellular life burst out all over the planet. Scientists point to this critical period as leading to life as we know it today, although its precise causes were not...

884faa2a157d81895cd80d16cc432b481
2009-05-28 12:01:50

U.S. scientists are challenging the prevailing views of the effects of the so-called Snowball Earth glaciations on life on Earth. Researchers from the University of California-Santa Barbara analyzed microfossils found in rocks at the bottom of the Grand Canyon to challenge current theories concerning the effects of the glaciers occurring approximately 635 million to 726 million years ago. Those glaciations are thought to have been responsible for the widespread deaths of early life on Earth....

41adbb02d7e5f83452ba076e552f15841
2009-05-26 15:17:08

New fossil findings discovered by scientists at UC Santa Barbara challenge prevailing views about the effects of "Snowball Earth" glaciations on life, according to an article in the June issue of the journal Nature Geoscience. By analyzing microfossils in rocks from the bottom of the Grand Canyon, the authors have challenged the view that has been generally assumed to be correct for the widespread die-off of early life on Earth. "Snowball Earth" is the popular term for glaciations that...

209b8207f42c76bbe4a84c18822794da1
2009-05-07 13:27:52

An international team of geologists may have uncovered the answer to an age-old question - an ice-age-old question, that is. It appears that Earth's earliest ice age may have been due to the rise of oxygen in Earth's atmosphere, which consumed atmospheric greenhouse gases and chilled the earth. Alan J. Kaufman, professor of geology at the University of Maryland, Maryland geology colleague James Farquhar, and scientists from Germany, South Africa, Canada, and the U.S.A., uncovered evidence...

2009-02-05 14:48:02

U.S. scientists say they have found fossil evidence of animals living on Earth more than 635 million years ago, the oldest such finds. Researchers from the University of California-Riverside, the Massachusetts Institute of Technology and other institutions used compounds preserved in sedimentary rocks to confirm the existence of demosponges. Demosponges appeared during the Neoproterozoic era, 1,000 to 542 million years ago, an era of climatic extremes and biological evolutionary developments...

1cf3ee4104fac943585cdab06dcf80b41
2009-02-04 17:29:32

Scientists announced on Wednesday the discovery of the earliest evidence of animal life to date. Chemical traces found in 635-million-year-old rocks in Oman provide key evidence to support Darwin's theory that simple organisms existed before the evolution of more complex creatures, researchers said in the Feb. 5 issue of the journal Nature. "Basically we have found a thread of that evidence that he predicted should be there," Roger Summons, a geobiologist at the Massachusetts Institute of...

6911c6e0ad9482f0cead76dc53452410
2008-10-05 16:40:00

The fossilized trail of an aquatic creature suggests that animals walked using legs at least 30 million years earlier than had been thought. The tracks -- two parallel rows of small dots, each about 2 millimeters in diameter -- date back some 570 million years, to the Ediacaran period. The Ediacaran preceded the Cambrian period, the time when most major groups of animals first evolved. Scientists once thought that it was primarily microbes and simple multicellular animals that existed prior...

2008-09-19 03:00:23

By Zhu, Wenbin Zhang, Zhiyong; Shu, Liangshu; Lu, Huafu; Su, Jinbao; Yang, Wei Mafic dykes are observed in the Korla region along the northern Tarim Block, NW China. Our sensitive high-resolution ion microprobe U-Pb zircon ages, the first determined for these dykes, indicate that the mafic dykes were mainly formed at 650-630 Ma, and thus document the youngest known igneous activity associated with rifting in the Tarim Block during the Neoproterozoic. Combined with previous geochronological...

2008-08-07 06:00:34

By Steve Kuchera, Duluth News-Tribune, Minn. Aug. 7--IT DOESN'T LOOK EXTRAORDINARY -- but a rock found in Antarctica by a University of Minnesota Duluth professor is helping researchers reconstruct what a supercontinent that existed a billion years ago looked like. Analysis of the chunk of granite collected by UMD geology professor John Goodge in 2005 indicate that part of Antarctica and North America were joined 1.4 billion years ago. "We got really lucky -- I had no idea what we were...


Latest Proterozoic Reference Libraries

Geologic Clock With Events And Periods
2012-11-18 19:10:56

The Neoproterozoic is the third of three subdivisions of the Proterozoic Eon (occurring from 1 billion years ago to 542 million years ago). This terminal era of the Proterozoic is itself divided into three sub-periods called the Tonian, Cryogenian, and Ediacaran Periods. The most severe glaciation known in the geologic record occurred during the Cryogenian Period, when ice sheets reached the equator and formed a possible “Snowball Earth.” And the earliest fossils of multi-cellular life...

Geologic Clock With Events And Periods
2012-11-18 19:08:04

The Paleoproterozoic is the first of three subdivisions of the Proterozoic Eon (occurring from 2.5 billion to 1.6 billion years ago (Ga). This period is marked by the first stabilization of the continents, and also when cyanobacteria--a type of bacteria that uses biochemical processes of photosynthesis to produce oxygen--evolved. Experts have found paleontological evidence that during at least part of the Paleoproterozoic era, about 1.8 Ga, the earth year was about 450 days long, with days...

Geologic Clock With Events And Periods
2012-10-22 14:17:38

The Archean (formerly Archaeozoic) is a geologic eon between the Hadean and Proterozoic eons. The Archean Eon begins at roughly 3.8 billion years ago (Ga) and ends at about 2.5 Ga. But unlike all other geological ages, which are based on stratigraphy, The Archean eon is defined chronometrically. The lower boundary of 3.8 Ga has also not been officially recognized by the International Commission on Stratigraphy. The name Archean is derived from the ancient Greek (Arkhe), meaning...

More Articles (3 articles) »
Word of the Day
barghest
  • A goblin in English folklore, often appearing in the shape of a large dog and believed to portend imminent death or misfortune.
  • A ghost, wraith, hobgoblin, elf, or spirit.
The origin of 'barghest' is not known, but it may be from perhaps burh-ghest, town-ghost, or German Berg-geist (mountain spirit) or Bär-geist (bear-spirit).
Related