Quantcast

Latest Proterozoic Stories

2007-09-28 12:17:27

WASHINGTON -- Oxygen, key to life on Earth today, began to appear on the planet millions of years earlier than scientists had thought, new research indicates. An analysis of a deep rock core from Australia indicates the presence of at least some oxygen 50 million to 100 million years before the great change when the life-giving element began rising to today's levels, according to two papers appearing in Friday's edition of the journal Science. Previously, the earliest indications of oxygen...

41f4ce01bdaa02ab7c973a68bf785f781
2006-06-07 08:05:00

It has been 2.3 billion years since Earth's atmosphere became infused with enough oxygen to support life as we know it. About the same time, the planet became encased in ice that some scientists speculate was more than a half-mile deep. That raises questions about whether complex life could have existed before "Snowball Earth" and survived, or if it first evolved when the snowball began to melt. New research shows organisms called eukaryotes - organisms of one or more complex cells that...

2005-09-29 19:30:00

A study that applied innovative techniques to previously unexamined rock formations has turned up strong evidence on the "Slushball Earth" side of a decades-long scientific argument. The study appears in the Sept. 29 Science Express. The lead author is Alison Olcott, a Ph.D. student of earth sciences in the USC College of Letters, Arts and Sciences. Geologists agree that prehistoric Earth was locked in a deep freeze during Precambrian times, about 750 to 600 million years ago. They disagree...

674d7c51aa389e1e4362db9979b1b3231
2005-08-11 06:20:00

Boulder -- An experiment in a dry Antarctic stream channel has shown that a carpet of freeze-dried microbes that lay dormant for two decades sprang to life one day after water was diverted into it, said a University of Colorado at Boulder researcher. The results showed the resilience of life in the harsh polar environment, where temperatures are below freezing for most of the year and glacial melt water flows for only five to 12 weeks annually, said Professor Diane McKnight of CU-Boulder's...

2005-08-09 23:37:28

An experiment in a dry Antarctic stream channel has shown that a carpet of freeze-dried microbes that lay dormant for two decades sprang to life one day after water was diverted into it, said a University of Colorado at Boulder researcher. The results showed the resilience of life in the harsh polar environment, where temperatures are below freezing for most of the year and glacial melt water flows for only five to 12 weeks annually, said Professor Diane McKnight of CU-Boulder's Institute of...

2005-07-11 19:20:00

Blacksburg, Va. July 11, 2005 "“ Scientists interested in ancient life have a wealth of fossils and impressions frozen in rocks that they can study from as far back as 540 million years ago "“ when animals with shells and bones began to become plentiful. But evidence of complex life older than 540 million years is scant and difficult to study. Now, a research team from Virginia Tech in the United States and Nanjing Institute of Geology and Paleontology in China has discovered...

2005-06-02 22:45:02

Boulder, Colo. - The June issue of GEOLOGY covers a wide variety of potentially newsworthy subjects. Topics include: discovery of 21 Martian river channels and estimates of their discharge and runoff production; evidence for olivine-rich bedrock on Mars; regional dynamics of global climate change; a challenge to the mantle plume hypothesis; constraints on late Neoproterozoic glaciations; new modeling of pyroclastic currents and possibilities for human survival in 79 A.D. Pompeii; the...


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
call-note
  • The call or cry of a bird or other animal to its mate or its young.
'Call-note' is newer than 'bird-call,' which originally referred to 'an instrument for imitating the note of birds' but now also refers to 'the song or cry of a bird.'
Related