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Latest Proterozoic Stories

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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...

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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...

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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...

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2008-07-17 16:15:00

A lone granite boulder found against all odds high atop a glacier in Antarctica may provide additional key evidence to support a theory that parts of the southernmost continent once were connected to North America hundreds of millions of years ago. Writing in the July 11 edition of the journal Science, an international team of U.S. and Australian investigators  describe their findings, which were made in the Transantarctic Mountains, and their significance to the problem of piecing...

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2008-04-22 12:20:00

In a paper published in this month's "ËœGeophysical Journal International', Dr Graeme Eagles from the Earth Sciences Department at Royal Holloway, University of London, reveals how one of the largest continents ever to exist met its demise.Gondwana was a "Ëœsupercontinent' that existed between 500 and 180 million years ago. For the past four decades, geologists have debated how Gondwana eventually broke up, developing a multitude of scenarios which can be loosely grouped...

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2008-02-26 11:55:00

The rise of oxygen and the oxidation of deep oceans between 635 and 551 million years ago may have had an impact on the increase and spread of the earliest complex life, including animals, according to a study reported in the Proceedings of the National Academy of Sciences online Early Edition during the week of February 25 - 29.Today, we take oxygen for granted. But the atmosphere had almost no oxygen until 2.5 billion years ago, and it was not until about 600 million years ago when the...

2007-11-11 03:00:00

By Shen, Bing Xiao, Shuhai; Dong, Lin; Zhou, Chuanming; Liu, Jianbo ABSTRACT- Upper Neoproterozoic successions in the North China and nearby Chaidam blocks are poorly documented. North China successions typically consist of a diamictite unit overlain by siltstone, sandstone, or slate. Similar successions occur in Chaidam, although a cap carbonate lies atop the diamictite unit. The diamictites in both blocks have been variously interpreted as Cryogenian, Ediacaran, or Cambrian glacial...


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...

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Word of the Day
snash
  • To talk saucily.
  • Insolent, opprobrious language; impertinent abuse.
This word is Scots in origin and probably imitative.