Granite Helps Scientists Piece Together Rodinia

If you’ve taught plate tectonics at the middle school level, you’re probably quite familiar with the supercontinent Pangaea. But did you know that Pangaea was not the only supercontinent in earth’s history – just the last to date? Millions of years before Pangaea, another supercontinent known as Rodinia united all of earth’s landmass in an unusual configuration. While we tend to think of Pangaea as the “starting point,” earth’s land and ocean basins have been continually shaped throughout geologic time through a supercontinent cycle.

While Pangaea certainly gets more press, Rodinia was the star of an article in the July 11, 2008 edition of Science. As summarized in a National Science Foundation News release, John Goodge’s team was collecting geologic specimens in the Transantarctic Mountains when they discovered a single granite boulder atop Nimrod Glacier.

Andrew Barth (L) and Devon Brecke (R), collecting glacial moraine samples in the Miller Range of the Transantarctic Mountains. Photo courtesy of John Goodge, University of Minnesota.

Subsequent chemical and isotopic tests indicated that the boulder was strikingly similar to a belt of igneous rock running through the southwestern United States. These similar chemical and isotopic signatures provided support for the SWEAT (southwest United States East Antarctica) hypothesis, which states that East Antarctica was connected to the southwestern United States approximately one billion years ago, as part of the global supercontinent Rodinia.

The supercontinent Rodinia as it began to break up approximately 750 million years ago.

At the heart of Rodinia was Laurentia, or the precursor to most of North America. Debate exists, however, on whether East Antarctica, Australia, Siberia, or South China fit with the western margin of Laurentia. This geologic discovery provides three lines of evidence in support of an East Antarctica – Laurentia connection.

Researchers theorize that about 600-800 million years ago, a portion of Rodinia broke away, gradually drifting southward to become eastern Antarctica and Australia. This movement just predates the Cambrian explosion, a rapid diversification of life and sudden appearance of complex organisms. Goodge explains that “there are ideas developing about these connections between the geo-tectonic world on the one hand and biology on the other.” It is possible that the shifting and colliding of continents, erosion, and influx of minerals and chemicals into the ocean may have provided nutrients to support a growing diversity of organisms.

Connecting to the National Science Education Standards

As with a discussion of Pangaea or plate tectonics in general, this article provides an opportunity to meet the Earth and Space Science standard’s various concepts. According to the National Science Education Standards, “The idea of systems provides a framework in which students can investigate the four major interacting components of the earth system – geosphere, hydrosphere, atmosphere, and the biosphere. In this holistic approach to studying the planet, physical, chemical, and biological processes act within and among the four components on a wide range of time scales to change continuously earth’s crust, oceans, atmosphere, and living organisms.” The holistic approach described in the NSES is reflected in this study’s use of geologic evidence to explain an important biological phenomenon.

How to Turn This News Event into an Inquiry-Based, Standards-Related Science Lesson

Rather than spark a new lesson, this current event provides an opportunity to revisit a familiar unit on plate tectonics, geologic time, and rocks and minerals. Most teachers include a discussion of Alfred Wegner and the evidence for his theory of plate tectonics, including similar fossilized plants and reptiles found in South America and Africa.

After students understand how Wegner used geologic and fossil evidence to reconstruct Pangaea, present the evidence from this most recent discovery. Ask them to explain how the same type of granite could be found in eastern Antarctica and the southwest United States. Once students conclude that the two continents must have been connected, re-examine a diagram of Pangaea, which shows an African-Antarctic connection, not a North America-Antarctic one. How, then, could these two places have similar rocks?

A reconstruction of the supercontinent Pangaea. Image courtesy of Kieff via Wikimedia.

Referring to geologic time may help at this point. Using a modified time scale, remind students that Pangaea existed approximately 200 million years ago, while earth is approximately 4.6 billion years old. What did earth’s surface look like before Pangaea? Lead students to the conclusion that other supercontinents, like Rodinia, existed well before Pangaea. Introduce the concept of the supercontinent cycle.

This type of discussion naturally progresses to the mechanics and processes driving the cycle: plate movement. The following resources from the Middle School Portal can help you teach about earth’s interior and plate tectonics. It may also be helpful to brush up on concepts related to geologic time, as these processes span millions of years.

Geologic Time: Eons, Eras, and Epochs

Plate Tectonics: Moving Middle School Science

Once students understand plate interactions (rifting, subduction, sea-floor spreading), take a global view. Using a world map, plot the locations of plate divergence and convergence. Challenge students to predict what the next supercontinent will look like. For example, current plate movement indicates that as the Atlantic Ocean basin grows, the Pacific Ocean basin is shrinking. In the future, western North America may be connected to Asia in the earth’s latest supercontinent. This story from NPR, Amasia: The Next Supercontinent?, tells the possible story.

Introducing Rodinia as part of a greater supercontinent cycle presents plate tectonics as a driving force in a long-term pattern of constructive and destructive forces. It provides another opportunity for students to consider the cyclic change: a fundamental principle in science.

We Want Your Feedback
We want and need your ideas, suggestions, and observations. What would you like to know more about? What questions have your students asked? We invite you to share with us and other readers by posting your comments. Please check back often for our newest posts or download the RSS feed for this blog. Let us know what you think and tell us how we can serve you better. We appreciate your feedback on all of our Middle School Portal 2 publications. You can also email us at msp@msteacher.org. This post was originally written by Jessica Fries-Gaither and published July 24, 2008 in the Connecting News to the National Science Education Standards blog. The post was updated 2/8/12 by Jessica Fries-Gaither.

26 thoughts on “Granite Helps Scientists Piece Together Rodinia

  1. I am not a teacher, but this is freakin’ fascinating… Here in New Zealand we have a FirstLight channel that teaches that Earth is 6000 years old and humans are descendands of Noah since 2400 BC, quite seriously with presentable guys looking and acting like educated “scientists” lecturing from a pulpit with PowerPoint presentations. It’s sometimes entertaining and bewildering; so, who but not the teachers are to make sure kids differentiate between evidence and fiction (while respecting religion for valid moral values and as the foundation of art and culture), and aren’t brainwashed into taking the old scripts literally in the 21st Century.

  2. Je suis sûr qu’il ya beaucoup de visiteurs qui copient cet article et annonce même sur les réseaux sociaux. Ils peuvent au moins donner crédit à l’auteur

  3. There is another part to the no contact policy that is just as important if you want
    to get him back. However, I am not trying to condemn you,
    making you feel low, instead, that could be a strong
    reminder and warning so that you have to treasure your love one,
    for him not to leave you anymore. He’s pulling away from you, and you feel like the impending breakup is inevitable.

  4. Rodinia is hypothesised to have broken up in the Neoproterozoic with its continental fragments re-assembled to form Pannotia 600–550 million years ago. In contrast with Pannotia, little is known yet about the exact configuration and geodynamic history of Rodinia.

  5. Let us commence a journey into the much travelled topic of Tom
    Clancy’s The Division keygen. The constantly changing fashionable take on Tom Clancy’s
    The Division keygen demonstrates the depth of the subject.
    Remarkably Tom Clancy’s The Division keygen is heralded by
    shopkeepers and investment bankers alike, leading many to state that several of todays most brilliant minds seem incapable of recognising its
    increasing relevance to understanding future generations.
    Since it was first compared to antidisestablishmentarianism
    much has been said concerning Tom Clancy’s The Division keygen
    by global commercial enterprises, who just don’t like that sort of thing.
    Though I would rather be in bed I will now examine the
    primary causes of Tom Clancy’s The Division keygen.

    Social Factors

    While some scholars have claimed that there is no such thing as society, this is rubbish.
    When Sir Bernard Chivilary said ‘hounds will feast on society’ [1]
    he, contrary to my learned colleague Sir George Allen’s recent
    publication ‘Into the eye of , could not have been referring to eighteenth century
    beliefs regarding society. Much has been said about the influence of the media on Tom
    Clancy’s The Division keygen. Observers claim
    it provides standards by which we may judge our selves.

    Special care must be taken when analysing such a delicate subject.
    On the other hand anyone that disagrees with me is an idiot.
    To put it simply, people like Tom Clancy’s The Division keygen.

    Economic Factors

    Increasingly economic growth and innovation are being attributed to Tom Clancy’s The Division keygen.

    We will begin by looking at the Watkis-Teeth-Pulling model, a classic economic
    system of analysis.

  6. But should you prefer richer taste of drinks, then vacuum type machine or manual type
    machine can be a better choice. With dozens of options of coffeemaker now it is possible to choose one which will suit to your
    personal need. Its versatility and functionality has produced
    it the “most used” coffeemaker in workplaces,
    exceeding 200,000 office installations in North America.

  7. And here’s a good tip: if your bag’s cleaning instructions call for air drying in a
    tumble dryer, try throwing a few tennis balls in
    with the sleeping bag. The CFM measure is useful for determining the vacuuming ability.
    Backpacks come in a variety of designs, forms, shapes and colors.

  8. The subject of clear skin diet is a controversial issue.
    The constantly changing fashionable take on clear skin diet demonstrates the depth of the subject.
    While it has been acknowledged that it has an important part to
    play in the development of man, its influence on western cinema has not been given proper
    recognition. Inevitably feelings run deep amongst the aristocracy,
    whom I can say no more about due to legal restrictions.
    Hold onto your hats as we begin a journey into clear skin diet.

    Social Factors

    Society is our own everyday reality. The immortal and indispensable phrase �honesty is the best
    policy� [1] created a monster which society has been attempting to tame ever since.
    No symbol is more potent than clear skin diet in society today.
    It is crunchy on the outside but soft in the middle.

    Our post-literate society, more than ever before, relies upon clear skin diet.
    It is intrinsically linked to adolescent inner acclimatisation.

    Economic Factors

    There has been a great deal of discussion in the world of economics, centred on
    the value of clear skin diet. We will study the Watkis-Teeth-Pulling model, as is standard in this
    case.

    My webpage flower headband

  9. What’s Going down i’m new to this, I stumbled upon
    this I have found It positively helpful and it has aided me out loads.

    I’m hoping to give a contribution & assist other customers like its aided me.
    Great job.

  10. naturally like your web-site but you have to test the spelling on quite a few of your posts.
    Several of them are rife with spelling issues and I in finding it very bothersome to tell
    the truth however I’ll surely come again again.

  11. I visited multiple web pages except thee audio quality for
    audio songs present at this web page is in faxt marvelous.

  12. I have been exploring for a little for any high-quality articles or weblog posts on this
    sort of house . Exploring in Yahoo I at last stumbled
    upon this web site. Reading this info So i’m happy to show
    that I have a very just right uncanny feeling I came upon exactly what I needed.
    I most unquestionably will make certain to don?t overlook this
    site and provides it a glance on a continuing basis.

  13. These plans and patterns are usually for do-it-yourself projects,
    such as building a wooden playhouse or carving a wooden Nativity scene.
    Acquiring woodworking ideas can get costly if you’re getting excellent options and not generic junk.
    You will also be able to prospect, or mine, ores and them smelt the metals that you need –
    or want to sell for a profit.

  14. But it is not so good for drying food, since it takes less than 200 degrees to dehydrate food.
    Baked good, for example, need to be cooked evenly, while most meats need to be
    seared on top. Before purchasing any appliance for your home,
    you must read reviews from users and experts given on the online shopping portals.

  15. Let it seem like you are continuing with your life normally.
    Rule 1- Don’t Think Too Much or Get “Too Deep” Here comes the first step
    of making an exit. That could have something to do with the
    fact that I.

  16. Hi, its fastidious article regarding media print, we all be aware of
    media is a wonderful source of facts.

    my web blog; seo

  17. If some one wants to be updated with most recent technologies therefore
    he must be pay a quick visit this web site and be up to date every day.

    My site: Rodrick

  18. its fastidious article regarding media print, we all be aware of media is a wonderful source of facts.Great post thanks for sharing this.

  19. Ij’s best to pay a vsthis in turn this won line site and reading the seems to of all connects regaimage this post: d while i am hoping am also eager inside of their getting familiareness.

Leave a Reply

Your email address will not be published.

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>