Younger, hotter Earth still not understood

Sep 13, 2010
Younger, hotter Earth still not understood
Satellite image of the Hudson Bay region. (Image by NASA)

Plate tectonics may not have operated on a younger and hotter Earth according to new research from the University of Bristol carried out on preserved remnants of ancient continental crust in the Hudson Bay region of Canada.

The processes that formed and shaped the early ’s crust are still poorly understood, and the onset of plate tectonics has been estimated as being as early as the Hadean (4.6-3.8 billion years ago) or as late as the Neoproterozoic (1,000-542 million years ago).

The Hudson Bay region represents an excellent opportunity to investigate crustal formation during the (that is from the formation of the Earth, almost 4.6 billion years ago, until 542 million years ago).  It records tectonic events leading to the formation and stabilisation of the Laurentian continent (most of modern-day North America) and also preserves crust with ages spanning around 2 billion years.

David Thompson, a PhD student in Bristol’s Department of , and colleagues from the University of Calgary and the Geological Survey of Canada analysed the structure and thickness of the crust using seismic waves to investigate what tectonic process were operating on the younger Earth.

They found that the crust between 3.9 and 2.7 billion years old had a relatively simple structure with no clear signs that it was subjected to the kind of plate tectonic processes operating now.  The crust that formed about 1.8 billion years, however, showed evidence of the collision of two continents, similar to the collision between India and Asia still ongoing today.

The researchers then compared the observed structure of the Hudson Bay crust with of a similar age found elsewhere in the world. They concluded that modern-style plate tectonics may not have been established until as late as 1.8 billion years ago.

The research is published in and was named as one of the Nature Geoscience's research highlights in their September issue.

Explore further: The Albian Gap, salt rock, and a heated debate

More information: Precambrian crustal evolution: Seismic constraints from the Canadian Shield by D.A. Thompson, I.D. Bastow, G. Helffrich, J-M. Kendall, J. Wookey, D.B. Snyder, D.W. Eaton Earth and Planetary Science Letters 297 (2010) 655-666. www.sciencedirect.com/science/journal/0012821X

Related Stories

Bias in the rock record?

Jan 14, 2009

(PhysOrg.com) -- The fossil record is known to be biased by the unevenness of geographical and stratigraphical sampling, and the lack of exposed rocks containing fossils. In a recent Perspective in Science [2 Jan ...

Mapping Venus: Extreme makeover or plate tectonics?

Mar 22, 2010

(PhysOrg.com) -- Venus and Earth have long been thought of as sister planets. Given its similar size and proximity to Earth in the inner Solar System, Venus might seem like a promising candidate for having ...

Study reveals ancient rocks linked to old Earth's crust

Feb 24, 2010

(PhysOrg.com) -- A new geological study which took place in the Pilbara region of Western Australia brings us one step closer to understanding more precisely the timing of when the primordial earth crust was ...

Mediterranean Sea dried up five million years ago

Feb 16, 2009

(PhysOrg.com) -- Upward movement of the Earth's crust transformed the Straits of Gibraltar into a dam. Approximately five million years ago, the Mediterranean Sea dried up after it was sealed off from the Atlantic Ocean. ...

Recommended for you

The Arctic: Interglacial period with a break

41 minutes ago

Scientists at the Goethe University Frankfurt and at the Senckenberg Biodiversity and Climate Research Centre working together with their Canadian counterparts, have reconstructed the climatic development ...

Building collapse during earthquake aftershocks

54 minutes ago

Earthquakes kill, but their aftershocks can cause the rapid collapse of buildings left standing in the aftermath of the initial quake. Research published in the International Journal of Reliability and Sa ...

Large igneous provinces associated with mid-ocean ridges

3 hours ago

Lip reading normally involves deciphering speech patterns, movements, gestures and expressions just by watching a person speak. Planet Earth has LIPS, too - they are an acronym for large igneous provinces, ...

Volcanic ash proves inefficient cloud ice maker

4 hours ago

When tons of ash spewed into the atmosphere from a 2010 Icelandic volcano it caused havoc for vacationers across Europe. But did it also dramatically change clouds? Researchers at Pacific Northwest National ...

New technique allows study of clouds in 3-D

4 hours ago

With two off-the-shelf digital cameras situated about 1 kilometer apart facing Miami's Biscayne Bay, Lawrence Berkeley National Laboratory scientists David Romps and Rusen Oktem are collecting three-dimensional ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.