I find myself in New Hampshire right now because we received a phone call that had the words "dad, brain, surgery and cancer" all in the same sentence. Unfortunately air travel tickets were at a premium so we elected to drive. The drive while long was uneventful but it brought to mind a question poised by a student on my last field class.
How are continents made? Every earthscience teacher in the K12 world teaches about continents. They all explain to their students about how continents "float" while oceanic crust "sinks" They all explain how new oceanic crust is "created" at spreading centers, but none of the group I had ever discussed how continents are made.
A quick survey of my class found that no one really discussed this chapter of geology. I was wondering. Do university classes skip this? Do university students just forget this part? Or has this knowledge level eroded away?
Sunday, July 12, 2009
Callan talks about desk crop-samples. Here are two examples of "parking-lot-crop-samples".
How many times has someone come up to you as a geologist and asked you to identify a rock sample? How many times has the sample in question come from a nearby parking lot? This happens to K-12 teachers all of the time.
Many K-12 teachers are not geoscientists and I tell them that context will help them in trying to identifying the rock sample. They must ask the kids about the location that the rock came from. It helps the kids in creating the description of the
their rock sample as well as giving you an idea of what the name is .
I was particularly interested in how the crystalline sample was found next to the conglomerate sample. It is obvious that the they did not originate in the same place but both had been transported to this location. This can lead to a great discussion about how rocks can be moved: water, wind, truck.
Over the years, these parking lot samples have kept me on my toes, especially that one GEO 101 lab where the TA gave me some aged concrete to identify. I quickly learned that lesson.
Saturday, July 4, 2009
In response to Magmalicious' question about why I ended up as a geo-scientist instead of perhaps a stock broker??
Neither of my parents nor anyone in my immediate family was interested in science...never mind the geo-sciences. It was in high school when I found that the landscapes I had been walking, climbing. biking and canoeing through had stories that could be teased out of the rock. It seemed that by following a few simple rules anyone could piece together this tale. I was hooked. What other field allowed me to be outside all the time and to do real science?
Studies in glaciology let me see why our backyard was full of cobbles from distant places and why the nearby lake was called a kettle pond and why Cape Cod is so rocky
Later, as an undergrad in Colorado, learning how seas had come and go through the years creating alternating layers of sandstone and shale out on the Eastern plains.
And then I found western Colorado with tertiary volcanics and sandstone canyons.
I decided to enter the world of the K-12 science teacher. In that time I figure that I have seen over 3000 students. I hope that I have shared this love of the outdoors, the story of landscape formation and how we can tease information out of the very rocks themselves.
Friday, July 3, 2009
One of the greatest classrooms I have ever had the opportunity to use has been the Colorado River. We spend 3 days camping and canoeing and doing geology for a teacher enhancement course. That means I teach teachers some simple geology and we all share ideas how we can bring kids into the world of rocks and rivers.
Looking down into the Grand Valley on day 1.
Canoeing past Entrada walls
Hiking into side canyons. Here the stream cuts into pre-Cambrian "Black Rocks" dated at 1.7 b.y. and is overlain by the Chinle formation aged approximately 0.2 b.y. Everyone thought that walking on 1.5 b.y of missing time was an impressive Saturday afternoon stroll.
The arches of Mee Canyon. The erosive potential of the Wingate sandstone is seen here. The Kayenta caprock is missing and the windblown Wingate creates evenly placed joints that erode into columns. Our lab that day was to establish the height of the columns and then using the average local incision rate of 0.14 ft/1K years to calculate how long this canyon has been around...a fun time with math!