Ensimatic

I am sitting in the Imaging Center working on my thesis: for now that means reading through really dense papers about Appalachian orogenic belts. Joy of joys.

Okay, it isn’t that bad, but I’d rather be outside on this beautiful day.

Anyway, here I am shedding tears and drops of sweat over 50 page papers on Silurian suture keys when I come across this gem: “It marks where the Ordovician Tetagouche-Exploits ensimatic back-arc basin (TEB), which opened within the leading peri-Gondwanan Gander terrain, finally closed.” Besides the mouthful of ancient geologic events and geographic places there is only one word that stumped me. Ensimatic. Solution? Google.

Double take. Fourth hit.  “Rhymes with ensimatic…” What?! Of course that is why I am looking up this really arcane, unused word, Google. Of course. Unable to move any further without clicking on this gem of a link I succumbed to taking a little break.

And let me tell you, it was enlightening.  There are 76, yes!, seventy-six, words that rhyme with ensimatic according to rhymebrain.com. Which is, well, amazing, because I would so much rather be writing poetry about rocks than an annotated bibliography.

Laurentia is just chilling in the west,
Not knowing, a back-arc basin is doing its best:
To move on over and collide is its quest.
Its movement is swift because its ensimatic,
When it hits, it will be problematic,
Because this back-arc basin is pretty erratic.

.

And now, Google has proved far more of a distraction than what would be considered a normal work break. Back to the annotated bibliography I go…

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P.S. After looking up “simatic” I was able to deduce that ensimatic means that the back-arc basin is perched on the lowest layer of the Earth’s crust, which is rich in both silica and magnesium and usually contains a high about of basaltic magma. Hopefully that is what it means because if I have to look up more words I might begin writing an ode.

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Recently, the state geologist for Maine, Bob Marvinney, came and visited our compound. We gave him a grand tour of the peninsula and showed him around the rocks. There will be more to come on this excellent visit and some of the rocks we saw, but to keep yourself busy have a look at the Maine Geological Survey’s website.

It is a great resource for us and for geology fanatics across the globe. The most important publication on the website for us is the 1:100,000 Bath Quadrangle and map published in 2002 by Hussey and Berry. it is in the maps and publications page.

A Propah Lobstah Dinnah at Shortridge Coastal Center

Aside

 

 

 

 

 

Working Inside

We have spent a lot of time out of doors over the last couple weeks but as we cover more and more area we are starting to spend some more time on the computer. The evenings of last week and today’s rainy Monday were good opportunities to get some serious debate in over polygons and map details.

Soon, once we have some more detailed polygons, I’ll post the work in progress. For now, here are some images of us in debate and working together on drawing some lines… We project the map on the wall so all four of us can work together.

Mapping with the input of four different people can be incredibly challenging.

Here is Heather at the control center and we call this person the “driver” because using ArcGIS is like driving an 18-wheeler. Or so I think.

Peter added his thoughts from the eastern side of the peninsula.

That’s all for now from Shortridge! More to come soon!

Measuring Rocks?

What does it mean to measure a rock? I know this is what you have been thinking about ever since you subscribed to this blog several months ago. And to satisfy your insatiable hunger for geology-knowledge I, Haley, will present a tutorial on measuring folds in rocks.

WHAT?! Rocks have folds????

In fact! Yes! They do. Have a look:

This is a wonderful fold in three dimensional view. Peter and I found it  near Singing Sands Beach – the southernmost cove on Small Point. Now, you can see all the layers shaped like half a cinnamon roll in the foreground and you should be able to see the continuation of those layers in a cylindrical fashion as you move your eyes to the background. Here is a little help (Yay, Powerpoint!):

Now, for the tricky part. You need to visualize the fold three dimensionally. It isn’t just a rock face you are looking at. Those layers extend toward the back of the picture. Similar to this cylinder:

So now you can see the fold, but how do you MEASURE it?

Be patient, young grasshopper and I shall tell all…

Geologists like to break things down into planes. Yes. Think Algebra. I know it hurts, but go with me:

Here is a plane that I can see pretty easily. Now, of course you are saying, “But you just made something curvy flat! You can’t do that!”

Response:

Yes.

I.

Can!

Explanation:

If you measure enough planes in a fold (three to be precise) you can later redraw the measurements and come up with a fold that is pretty darn close to this one. And here is where you break out the algebra. (Ahhhh!)  You need to visualize this plane in a coordinate system of three dimensional space. Instead of using ordinate and abscissa  axis though, we geologists simplify and use a cardinal direction! Yay! Only one number! You need to know the bearing of the plane.

In this photograph, you can see I have placed a north arrow on top of the plane. This way you can make a guess as to what the bearing of the limb is. I would say it is about NNE. In the field, we would use our compass to get an exact number for the bearing. This would probably be about 20° on a compass.

Now we only need one other measurement for this plane… Now, we need a third axis (like the z-axis in the cartesian coordinate system) in order to understand completely its orientation in space because we need to measure how vertical the plane is. Our measurement of the vertical incline of a plane is based on a concept and system that is the same no matter where you go in the world (unlike the cartesian system): gravity. We just need to measure the steepness of the plane to record its orientation in the third dimension. This steepness is measured as an angle from a flat horizontal line (a horizontal line, which is always exactly perpendicular to gravity).

Powerpoint has this nifty feature that snaps a line to the horizontal of the page. What comes on a compass is just as fun: we have compasses with levels so that we can find a horizontal line and measure the angle with ease.

Now, almost there. We measured one plane, we have two more.

The next is the other limb of the fold, which is essentially the above plane, just flipped to the other side of the layers. I think it should be fairly simple to visualize and I was running out of patience with Powerpoint, so you’ll have to use your imagination.

The trickiest thing to measure and visualize is the plane that cuts the folds in half and describes where the two limbs meet. Here is what that plane would look like:

You would use the same technique of cardinal direction and steepness to measure this plane. Once all the planes are measured, you have enough information to redraw the fold, or perhaps more importantly compare it to other folds and folding patterns in your area. The measurements of “cardinal direction and steepness” are known to geologists as “strike and dip.”

(Side note: When Peter and I were measuring today we met someone on the beach who asked us, “Are you measuring strike and dip?” We stared back in happy surprise to the man tanning on the beach and said, “Yes!” He told us he was a geo major from Lehigh University. As we told him the scope of our summer field work he reminisced about geology field camp at Lehigh. Somewhat of an “initiation camp” into the geology cult, he described. Me thinks we need some kind of “initiation camp”  at Bates… Harharhar.)

The size of folds, the frequency of folds, the shape of folds, and the orientations of folds can help a geologist come up with part of the story of the rocks you are looking at. It can also help explain the dynamic movement of rock miles below the crust – something you could never see with the naked eye.

Our workday office…

…Is beautiful.

We work on perhaps the most beautiful coastline in all of Maine. In the past week I (Haley) have seen more incredible wildlife than all the rest of my 21 years combined. The peninsula we are doing our mapping on is just… breathtaking. And, it is incredibly well preserved. The sad paradox of the peninsula is that it is all private property. It is probably home to some of the best preserved land and wildlife in Maine because it is untouched and owned by only a few families who don’t live there all year round. There is nothing like this in Acadia. All the roads have posted signs and you feel like quite an intruder, but in the name of science we were granted access most all off the rocky coastline of Small Point. So, we are the lucky un-owners that get to marvel at its beauty.

Here is a selection of photographs of the wildlife we have seen so far. You won’t believe it!

A whole pack of baby eiders!

A little baby turtle! See the next picture…

That is how baby he is!

A little baby sea otter was playing in the rocks with his brothers and sisters.

When I saw this baby seal sunning on the beach I almost cried with joy. He (she?) was so cute I couldn’t stand it. We were able to get pretty close too!

And here are four bobcats in the field! Jen, Heather, Peter and Dyk are measuring and mapping out a complicated fold in a granitic vein.

Getting the Goods

The spring semester is over at Bates and all of the people involved in our study have embarked on their Short Term excursions. Dyk is in the Southwest for the next month teaching a short term course of 14 students traveling from the rim of the Canyon to the top of the cinder cones. Heather and Jen are both working at the study site during short term doing a lot of preliminary research and mapping. While Jen and Heather slave away at Small Point, Peter and Haley are both rowing their way through Short Term. This weekend is actually the ECAC Championships.

Once Short Term is over and everyone has had a little break in June, the fun begins! With our project fully funded by the EDMAP Grant, beginning June 22nd we’ll be able to spend eight full weeks in the field. Getting full funding on the grant also means that our new equipment should be arriving soon. We already have the newest member of the family – the Juno:

We have already started testing it out in the field and doing some preliminary research.

This picture was taken at the end of our last day in the field of the semester. Professor John Creasy has deemed us "Dyk's Angels."

For now, that’s all the news from Small Point. More to come soon!