Saturday, August 31, 2013

The Ocean Bottom on the Mountain

Ernest Hemingway is rumored to have won a bet by telling the world's shortest story: "For Sale: Baby shoes, never worn."  As I sat on the side of Dorr Mountain, waxing geologically to my brother-in-law, he pointed out to me that the story I was telling was really much shorter than the words I was using.  Perhaps a shorter telling would have gone something like this: "Ocean bottom found on a mountaintop."

Hemingway's story was all about what it implied.  So what is implied by a four-foot boulder of ocean bottom rock?  Time.  Ignoring that this rock was part of a much larger formation, we can conclude that these four feet must have piled up over time.  One resource suggests that clay, likely once a major component of this chunk of sea floor, gathers at 10mm every thousand years.  This isn't a rock; this is a time lapse of 1.2 million years of arduously slow settling of clay.

So what about the mountain itself? The depths at which granite is formed are measured in miles (kilometers really, but this is America, right?).  That means that the bulb of granite that makes up most of Mount Desert Island once rested deep under the Earth's surface; now Dorr Mountain stands nearly a quarter mile above sea level.  Over the hundreds of millions of years since that deep magma cooled, wind, water and ice have excavated the remains of an ancient collision between North America and the ancient land mass on which MDI rests.

A look at the sea bottom rock implies something more. Several flat faces, on many planes, give evidence of glaciers. The glacier that plucked that rock from its original bed dragged the behemoth across the Earth's surface like cheese across a grater. The chaotic innards of the glacier occasionally flipped the mighty stone, smoothing yet another face.  The glacier, perhaps a mile tall, would have both ripped at Dorr, and been slowed by it. As the ice layed the mountain low, it may have slowed sufficiently to drop some of its load - seafloor included.

Hundreds of thousands of years of piling clay, miles of erosion, and an ice sheet a mile thick, all whispered in the language of rocks.  Scenes like this, like the glacier that came before them, cover Maine. Millions of shorts stories, implying so much more.


Ansley, J. E. 2000. The Teacher-Friendly Guide to the Geology of the Northeastern U.S. Paleontological Research Institution, Ithaca, NY.  

Hardcastle, Tim . "Pelagic clay ." Historical Geology- Wikibooks. Wikibooks, n.d. Web. 1 Sept. 2013. <http://en.wikibooks.org/wiki/Historical_Geology/

Miller, Robert B. , Scott R. Paterson, and Jennifer P. Matzel. "Plutonism at different crustal levels: Insights from the ~5–40 km (paleodepth) North Cascades crustal section, Washington." The Geological Society of America Special Paper 456 (2009)


Petford, N. , A. R. Cruden, K. J. W. McCaffrey, and J.-L. Vigneresse. "Granite magma formation, transport and emplacement in the Earth's crust." Nature408 (2000): 669-673. Print.

"Dorr Mountain : Climbing, Hiking & Mountaineering : SummitPost." Climbing, Hiking, Mountaineering : SummitPost. N.p., n.d. Web. 1 Sept. 2013. <http://www.summitpost.org/dorr-mountain/416282>.



1 comment:

  1. loved the writing and the story. thanks for another treat!

    ReplyDelete