 |
| Artwork by Troy Nickle |
Is time merely a limited linear concept created by mankind
so that we can understand the passing of the days, weeks and years?
We seldom think of time on a vast scale
encompassing thousands, millions and even billions of years. I wonder what the earth
looked like a billion years ago. How has our earth formed and evolved over that
period of what we call time? It’s hard to fathom, but I had the opportunity to
take a 6 day trip with geologist Mark Jirsa into the Boundary Waters Canoe Area
Wilderness, (BWCAW), to gain an understanding of Minnesota’s ancient bedrock
crust and had a glimpse of what the earth might have looked like millions of
years ago.
Mark focuses on Precambrian geology and studies and maps many of the rock outcrops in the BWCAW
and throughout Minnesota to improve our understanding of crustal evolution that
spans nearly 3 billion years - (2690 to 2722 Million years). Many of the exposures in the Boundary Waters area
provide examples of some of Earth’s oldest and most complex crust. Much of the bedrock in Minnesota is covered by
hundreds of feet of glacial sediment, but the
bedrock in Superior National Forest which includes the BWCAW is near or at land
surface, creating exposures that are sufficiently large and closely spaced
allowing it to be mapped in detail.
 |
| Photograph by artist Troy Nickle |
Mark tells me that he is trying to uncover the geological
story behind the formations in the rock. The once flat-lying strata has been
folded, metamorphosed (thermally altered), faulted and now stand nearly on end.
Like a detective Mark looks at the rock and tries to uncover the story behind
it. He looks at the layers measuring the direction with a compass, determining the strike or trend of the layer
and if possible the angle the layers recede into the rock, (the dip) and tries
to determine which way is up, (the topping) formed by an understanding of the
sediments in the layers, and how sediments settle- usually the heavier
sediments settle first then the lighter ones later. He takes a UTM (Universe
Transverse Mercator) reading of the location and writes a variety of geologist
nomenclature on the sediments that formed the rock, the type of rock, fault
lines and other information that will help him form detailed maps of the
geology. Mark is seriously passionate about his work and it is not hard if you’re
near him to soon be consumed with trying to understand and uncover the
geological story at how this ancient bedrock might have formed.
 |
| Photograph by artist Troy Nickle |
It took us 2 days to paddle out to our base camp in the
south arm of Knife Lake. There Mark and I developed a collaboration that would
bridge geology with art. Mark was really amazing to work with and helped form
some of the ideas driving the work. Through a discussion of where this work could
go and how to relate art with geology we decided to frame key areas of rock
formations, sediment layers, fault lines and other interesting areas of bedrock
as windows looking back into the ancient past. I used locally available materials
like stone, wood or reeds to create the frames placed over areas of bedrock and
created a frame that was 1 meter square and corresponded to a UTM
location. Mark took notes of the location,
the strike, dip, topping, type and age of rock, sediment formations and
numerous other details which will be part of the work while I created the frame
and took a detailed image of the rock within the frame and an image of where
the work exists in context to the land. Each rock formation is like a unique drawing
that forms interesting lines and textures telling a story of an ancient world.
During one day of mapping we documented 10 sites while hiking through the Knife
Lake burn of 2011. We walked through thick brush, fallen trees and endured the
high winds, heavy rain and later were rewarded with a spectacular view.We covered
a large area and when we got back to camp made plans to cover other areas on our route back.
No comments:
Post a Comment