Jack Hills Zircon: Evidence of a Very Old Earth

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In a report published in Nature Geoscience, a scientific team studying rocks in Australia, used Australian zircons in the Jack Hills that are embedded in the rocks to decide the age and history of these rocks.

They found evidence that the Earth’s crust first formed at least 4.4 billion years ago.  They analyzed the atoms in zircons and used them like a clock to decide when they were formed.  The clock inside the zircon is the radioactive element uranium, and over time it becomes lead.  Follow this to how zircon is used to date rocks.

Figure 1. 4.4 billion-year-old zircon crystal which is used to determine the age of the Earth.  Credit: John W. Valley/University of Wisconsin-Madison.
Figure 1. 4.4 billion-year-old zircon crystal which is used to determine the age of the Earth. Credit: John W. Valley/University of Wisconsin-Madison.

Zircon, a silicate mineral, is like a buried clock that has ticked from the time it formed or crystallized in molten magma.  Zircon crystals are tiny, but very resistant to geological process, including erosion and metamorphism.  Zircons can survive these processes, and the clock keeps ticking.

According to the researchers:

The Earth was assembled from a lot of heterogeneous material from the solar system,” Valley explains, noting that the early Earth experienced intense bombardment by meteors, including a collision with a Mars-sized object about 4.5 billion years ago “that formed our moon, and melted and homogenized the Earth. Our samples formed after the magma oceans cooled and prove that these events were very early.

Figure 2.  Time Line for a Very Old Earth showing the relationship of the Australian Jack Hills Zircon and the geological timeline of Earth. Photo: Andree Valley/University of Wisonsin-Madison.
Figure 2. Time Line for a Very Old Earth showing the relationship of the Australian Jack Hills Zircon and the geological timeline of Earth. Photo: Andree Valley/University of Wisonsin-Madison.

Although zircons were not mentioned in the recent Bill Nye and Ken Ham Debate on evolution, this research study surely adds to Bill Nye’s idea that the record in layers of rocks, ice cores, tree rings, and fossils provides evidence that the earth is very old.  On the other hand, Ken Ham would dispute the findings in the research study on Australian zircons because this is historical science, and we were not there to see this.

According to the researchers, the zircon data “confirms their view of how the Earth cooled very early“, and became habitable, pushing back even further when life began on earth.

Whether we like or not, the debate on the age of the Earth still goes on.  Nye’s ideas are supported, while Ham will continue to resist agreeing with the findings because his ideology is so strong that he will hold on to his “young earth conception.”

What are your views on the value of the Jack Hills’ zircon findings in discussions of the age of the Earth?



Governor Deal’s Weather Task Force is More of a Mob Than a Problem Solving Team

To improve the state of Georgia’s response to severe weather, Governor Nathan Deal appointed a 28 member task force.  A few years ago, when Atlanta educators were accused of changing answers on student tests sheets, the Governor (Sonny Perdue) appointed a panel of three to investigate and prepare a report.  Why do we need 28 people, many of whom simply do not have the time to investigate the state’s natural disaster alert system.

Governor Deal has appointed 28 people to meet and has charged them with coming up with plans to improve the state’s ability to respond to severe weather.  They must report back to the Governor within 60 days of their first meeting.

The task force is made up senior level people from various organizations in the state, public and private.  Figure 1 is a break-down of the Task Force into various categories:

Georgia Severe Weather Task Force


Chamber of Commerce




Georgia Emergency Management Authority (GEMA)


Governor’s Office






Natural Resources Dept.


Police, Fire & Safety


School Superintendents




Weather TV Announcers and National Weather Service

Figure 1. Georgia Severe Weather Task Force, Feb. 3, 2014

The Task Force is more a mob, and not a group that can solve problems and make recommendations.  But more than this is the fact that many of the members of this Task Force contributed to the Atlanta Weather Fiasco on January 28 – 29, 2014. If you look over the list of categories, the fundamental reason the state did NOT respond to the severe weather forecasts that we clearly made public on all four Atlanta TV stations, as well as the National Weather Service, in Peachtree City, Georgia.

Investigate the Georgia Emergency Management Agency/Homeland Security (GEMA)

The organization that should be investigated is GEMA.  GEMA has one mission, as stated on the GEMA website, and that is:

GEMA’s mission is to provide a comprehensive and aggressive all?hazards approach to homeland security initiatives, mitigation, preparedness, response, recovery and special events in order to protect life and property and prevent and/or reduce negative impacts of terrorism and natural disasters in Georgia.

The vision of GEMA is

Create a culture of preparedness by fostering partnerships between local, state and federal government, local business and industry, volunteer and faith-based organizations, and the citizens of Georgia.

And, according the Agency’s website, the Core Business is Mitigation, Preparedness, Response and Recovery.

GEMA failed in it mission, and one has to question its culture and core business ability.  Georgia’s ability to respond to natural disasters is dependent on GEMA’s competence to make decisions and take action based on information available to them from meteorologists, and other earth scientists.  It requires a mode of thinking that is ecological.  People who work at GEMA have to be schooled in systems thinking, and have the courage to make bold decisions based on available data.

The AJC uncovered and published emails sent to and from the Director of GEMA.  The emails do not support in any way boldness in decisions making, nor do they show that GEMA’s director has learned from earlier weather events in Atlanta.

If the Governor wants to improve the state’s ability to respond to natural disasters, it needs to go directly to the source of the problem, and that has to GEMA.

The Task Force should be disbanded before it meets, and instead, the Governor should appoint a smaller group of people who do not have the vested interests similar to the make up of the Severe Weather Task Force.  This committee should be charged with investigating the culture and operations of GEMA, and report back to the Governor on time.

Who would you recommend as members of a smaller committee to investigate GEMA?

NAT GEO The Wild Mississippi

NAT GEO presents The Wild Mississippi, a three-part TV program on Sunday, February 12.  I viewed the three episodes today, and recommend that you tune in Sunday night at 8:00 P.M (Eastern) to view the first of the three episodes.  The second and third episodes follow at 9:00 P.M. and 10:00 P.M.  Check the schedule and details here.

Join the Wild Mississippi Blog Carnival here.

If you are teaching life science, high school biology, earth science, or an ecology or environmental science course, you will find these programs great resources for your students.  I viewed the shows on my 27″ Mac, and the imagery is gorgeous as we travel the river, and witness the wildlife, and power of the Mississippi from its beginning in Minnesota and to the Mississippi River Delta in the Gulf of Mexico.

  • Episode 1: Wild Mississippi: Deep Freeze
  • Episode 2: Wild Mississippi: Raging Waters
  • Episode 3: Delta Blues
Gibson, LA: Wide shot of the bayou from the bow of the boat. (Photo Credit: © NGC / Whitney Beer-Kerr)Thibodeaux, LA: Cameraman Jeff Wayman leaning over the front of the boat. (Photo Credit: © NGC / Whitney Beer-Kerr)
Thibodeaux, LA: Cameraman Jeff Wayman leaning over the front of the boat. (Photo Credit: © NGC / Whitney Beer-Kerr)

Here are links to two videos that will show you the impressive quality of the shows. According to NAT GEO, they explored the length of the Mississippi for an entire year, traveling the full length of the river (2350 miles).

The Mississippi is an amazing river, and every time we cross this river, we are awed at its majesty as it traverses the the continent.

Video 1: Fishing with alligator snappers
Video 2: Bobcat prey



The Dinosaur Footprints Puzzle: Is it pedagogy or paleontology?

In the last post I reviewed the article “Tracking the Footprints Puzzle: The Problematic persistence of science-as-process in teaching the nature and culture of science by Charles Ault and Jeff Dodick which was published in the recent issue of the journal Science Education. I also reflected on my own experience in teaching and writing with the Footprints Puzzle.  In this post, I am going to explore this idea: The Dinosaur Footprints Puzzle: Is it pedagogy or paleontology?

Ault and Dodick, among other issues, highlight that science teachers have been preoccupied for a long time of how best to connect content and process and to teach scientific inquiry.  Questions arose such as how should schools depict science content and process in science inquiry.    Their view on this question is that teaching science as process was a premier trend and is revealed in this quote from their article:

From the 1960s through the 1980s, the scales tipped away from content as many science educators advocated “a process approach” (American Academy for the Advancement of Science [AAAS], 1967; Gabel, 1984) to teaching science. This approach treated a small number of content-free skills (typically 14 in AAAS’ Science: A Process Approach [SAPA]) as representative of the sciences, suggesting that mastery of these skills might enhance student learning in several different subjects. Furthermore, the process approach discouraged mixing content knowledge with training in process skills. Proponents worried that students might become confused by the content, feel discouraged, and therefore lose sight of the process objective. For example, in an exercise for teaching about hypothesis testing students were challenged to define variables influencing rotational speed of a “Whirly Bird” device, isolate an independent (or “manipulated”) variable, and test for the system’s response (also defined operationally as the dependent or “responding” variable) to the manipulated variable (Gabel, 1984, pp. 87–92; Science Curriculum Improvement Study & Berger, 1970). Developing the ideas of angular momentum and rotational inertia (or any intuitive precursors to these concepts) remained outside the lesson’s purview—unnecessary complications that might obscure the logic of experimental design central to the process of scientific inquiry.

The authors ague that science is more than process, and that the nature and concepts of the discipline of inquiry (geology, marine biology, astrophysics) ought to be an important part of science inquiry.  We would agree.  They explain the meaning in this passage:

Mary Budd Rowe, a scholar whose contributions to inquiry science remain unsurpassed (e.g., the role of language, wait-time, and fate control; Rowe, 1978), believed in the appeal to students of science as specially crafted stories about the natural world (Bianchini, 2008)—as meaningful interpretations of experiences (“experiments” being a particular type of experience). Paleontological interpretation of fossil dinosaur footprints is one such story. To learn this story means to journey through the landscape of genuine fossil artifacts guided by the imagery of evolutionary thought—to engage in disciplined inquiry. Paleontological inquiry, representative of the importance of context to observing and inferring in particular ways, promises fascinating stories that amplify experience with meaning (Ault & Ault, 2009).

The Footprints Puzzle as depicted in the original ESCP Text designed to help students investigate fossil dinosaur tracks.

So, as I raise in the title of this post, is the Dinosaur Footprints Puzzle a pedagogical exercise, or an experience in paleontology?  The original intent of the science educators that designed the Footprints Puzzle for the Earth Science Curriculum Project materials in the 1960s was an inquiry activity within the construct of paleontology.  Students were told that the footprints were dinosaur tracks, and they were informed that the tracks were fossils, and were made by dinosaurs in Texas during the Mesozoic Era.  The activity as originally used in the ESCP text was to help students use the tracks to tell a story about about dinosaurs, and how paleontologists use by process (measurement) and concepts (geological time) to interpret events in the rocks.  Naturally, the tracks as shown here represent tracks in nature, and as Ault and Dodick point out, the teacher would need to involve the students in examining real fossils, looking at real tracks, determining the age of the rocks in the area of the tracks, and other important paleontological concepts that would help them build a story.

The dinosaur track activity and its selection as an important activity in an earth science course is an example of the application of pedagogical content knowledge (PCK).  It is a powerful and useful form of representation of key ideas about fossils, and over time it has been recognized as one way to make some aspects of paleontology understandable to students.

The Footprints Puzzle has become for me an important tool in not only the teaching of geology and earth science, but as a vehicle for teaching science pedagogy.  In geology and earth science, I’ve used the Footprints Puzzle as an activity to help students explore fossils, and geological time.  Supplemented with field work to hunt for and collect fossils, students can use the Footprints Puzzle is use their imaginations to create stories about animals as they lived and roamed the earth, and in this case, during the the Mesozoic Era.

I would agree with Alt and Dodick that the original intent of the activity has been distorted by its use as a simple exercise in which students make observations and inferences about tracks on a piece of paper, with no context, or reference to real fossils, dinosaurs, and the earth’s past.  In some cases, the students are told these are tracks in the snow, perhaps by birds; in other cases, students simply make lists of observations.  Don’t get me wrong, there is nothing wrong with doing activities in science that focus on observations.  Many of us have used the CHEM Study activity in which students observe a burning candle and are challenged to make as many observations as they can.  Providing an authentic context (for the Footprint Puzzle) is tantamount to making use of research in the learning and cognitive sciences.  Much of the rationale for this approach can be traced back to John Dewey, and then forward to Lev Vygotsky, Jean Piaget, and Jerome Bruner.

In the next post I will explore how the Footprints Puzzle became an important tool for teaching teachers important teaching and learning strategies.

Water on the Moon

NASA has reported that if astronauts heated lunar soil, it would yield water that could be purified and used for drinking, or separated into Oxygen and Hydrogen and used for rocket fuel.

NASA scientists, of  Project LCROSS, have reported that there is water in one of the moon’s craters, and that there is more water in this crater than there is in the Sahara Desert.  The water, in the form of ice crystals, makes up about 5 – 8% of the crater’s mixture.  According to NASA, 8 wheelbarrows of soil could yield 10 to 13 gallons of water.

This was an unexpected result, as many have thought that the moon was barren of water.  Although there are no plans to go back to the moon, this discovery certainly certainly throws new light on NASA’s previous plan to go back to the moon, and use it as a staging ground for missions to Mars.  According to NASA, the water on moon could be used be broken apart into Hydrogen and Oxygen and used as rocket fuel.

In an article in the New York Times, the moon exploration was set in motion as follows:

Lcross and the lunar orbiter are part of NASA’s Constellation program, started five years ago by the Bush administration to send astronauts back to the Moon. Arguing that it is too expensive and that the United States has already been there, President Obama has pushed for its cancellation. A compromise on the space agency’s future, passed by Congress and signed into law by Mr. Obama last week, sets aside Moon ambitions for now, at least for the return of human explorers.