The Ausable River:

I took Geology precisely because of the Caring and Values part of this course. I’m an English and ARHA major and am therefore not accustomed to taking college-level science courses. However, at the beginning of this semester, I believed that knowledge of the physical world around me was an important component of my higher education, that it would enhance my connection to the natural world and broaden my horizons as a thinker and writer. After taking Suficial Earth Dynamics, I am even more cemented in this view, as well as my belief in the benefit of a true liberal arts education. This is not to say that I wasn’t immensely challenged by aspects of this course; during quarantine especially I had trouble grasping concepts and fully immersing myself in the knowledge being passed on through videos and worksheets. However, the challenges I faced are dwarfed by the way that my perspective on the natural world has shifted.

In my original journal prompt, I wrote about the Adirondacks: the National Park where I grew up and where I returned after Amherst closed down. My childhood home is surrounded by 40 acres of woodland, and bordered by the Ausable River. I found myself especially drawn to our unit on rivers because of the hundreds of hours I’ve spent swimming and sitting by the river next to my house. The Ausable River was named by Samuel de Champlain during his first explorations of the area. The original spelling was Au Sable, which is French for ‘sandy’, because de Champlain noticed its large sandy delta where it drained into Lake Champlain. However, the river is important not just as a significant part of my childhood or source of the Hudson, it also shaped the land I grew up on. Each summer day of my childhood spent running through the woods, I was unaware that the land I played on had been altered and shaped by the nearby river’s activity.

Luckily for me, the Ausable River Association already completed part of my work for me. As I started to look more at the land I had grown up on, I found a detailed map of the Ausable River’s watershed area. This showed me both the topographical map of the area, and the surficial geology of the land I grew up on.

 

Figure 1 (removed): Satellite Image of my childhood home and the land surrounding. House is marked with a star. The property covers the land between State Rt. 9N and the Eastern Bank of the Ausable.

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Surficial Geology of the area, via ausableriver.org

Figure 2: Surficial Geology of the area, via ausableriver.org Light Green: Kame Deposits. Dark Green: Recent Alluvium. Tan: Till.

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geological map of the bedrock of the Ausable River

Figure 3: Bedrock Geology of the area, via ausableriver.org Charcoal Grey (left half): meta anorthosite and anorthositic gneiss Dark Grey (center section): Undivided metasedimentary rock and related migmatite Medium Grey: Olivine metagabbro Light Grey: Charnock, manger, pyroxene-quartz syenite gneiss

A number of things about the surficial geology of my childhood home became clearer after I studied these maps. I’d already known that this section of the Ausable River was relatively flat and meandering because our house had been built between the straight road and the sinewy river. I’d had numerous cookouts on the river’s sandy point bar, and swum across to the cut bank, where the water was over my head. Much of the surficial geology - the till (tan) and kame deposits (light green) - of the surrounding area were part of the glacial landscape, but the ‘recent alluvium’ stood out as evidence of post-glacial processes. The alluvial deposit indicated that a recent flood had covered the glacial till. However, the flood must have occurred before the river was in its current location, because the alluvial deposition follows a less-sinuous pattern than the current Ausable.

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Alluvial deposition map of the Ausable River
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map of the current path of the Ausable River

Figures 4 & 5: Alluvial deposition map vs. current path of the Ausable River

I was glad to find new information about a place that feels very familiar to me; I learned a lot during the research process and gained a new appreciation for the factors that built my childhood home and the source of endless adventures. My relationship with that piece of land has evolved as I spend more and more time away from it. The geological perspective allows me to engage with the land in a different way. Instead of thinking about the last hundred years - with our 95-year-old neighbor who used to run on the same paths that I played on - I can think on a scale where alluvial deposition is a recent event, where the advance and retreat of glaciers are within memory, where, compared to water and ice, I am the least significant thing to ever move across this small stretch of land.

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2012 photo of girl (author) wading in Ausable River showing a very rocky shore

Figure 6: Photograph of me in the river, summer of 2012

 

Maeve Brammer Geology 112 Prof. David Jones

May 15, 2020