Sitting with Deep Time in Casco Bay
On a warm July morning, I walked half a mile down a grassy trail at Woodward Point Preserve in Brunswick to reach the rocky shore. My stroll through this 87.5-acre conserved peninsula felt, in a certain way, like time travel. I passed first through meadows of newly blooming goldenrod; then through older stands of pine, ferns, and blueberry bushes; then to the mica-flecked edge of Woodward Cove that has stood against the tug of tides for millennia.
At the edge of the sea, the past, present, and future swirl together. Resting my palms on the beige and grey stone, I touched back some 445 million years to the Silurian period, when the quartz and feldspar grains that comprise the rock first began accumulating at the bottom of a now extinct ocean. Over time, that seafloor debris became buried beneath Earth’s crust and pushed down into the mantle, where heat and pressure cooked it into metamorphic rock that later rose to the surface through further tectonic movements.
Much of the layered, rusty rocks throughout Casco Bay share a similar origin story. They formed long before legs ever carried any animals down grassy paths. When plants were just beginning to knit the ground in green and continents remained largely lifeless. With my hands touching down on that schist—that metamorphosed seafloor—I tried to imagine this younger Earth.
An osprey screamed overhead, calling me back to the present. Our lives brim with busyness, and with the heartbreaks of ongoing environmental crises and social injustices. These injustices and crises urgently demand our attention, call us to work for a healthier and more just future. Sitting on those Silurian rocks overlooking Woodward Cove, I was also reminded of the long arc of Earth’s 4.54-billion-year history and how brief our lives are in the scheme of that history. How fortunate we are to be here at all, to care for this place as well as we can while we can, and to remember that change will continue unfolding long after we’re gone.
Further offshore, another hump of even older metamorphosed seafloor rises up out of Casco Bay as Whaleboat Island. This 122- acre MCHT preserve sits about a mile west of Harpswell Neck and is made up of bedrock that formed some 465 million years ago, during the Ordovician period, when the very first backbones were just beginning to evolve within fish. The rocks themselves derive from ash and other debris that plumed out of a volcanic arc and settled at the bottom of a shallow sea.
On a recent visit, mist rolled over the neighboring islands as I tried to evoke that Ordovician world in my mind’s eye, conjure what it looked, smelled, and sounded like. I glanced around and stripped Whaleboat Island of its barnacled tidepools, its hay-scented fern, its spiderwebs and rose petals fluttering in the wind. I removed the seagulls crying above, and their stray feathers floating in the waves. I imagined a world in which none of these familiarities existed, when most of life’s dramas took place under the sea.
As long ago and far removed as this version of Earth may seem, this planet had already spun through more than four billion years before those quartzes and feldspars ever began coalescing to form the rock beneath me. These Casco Bay islands and peninsulas are, in the scheme of Earth history, quite young. And those rose petals stuck in the spiderwebs, the feathers floating in the barnacle-laden tide pools, the humans taking all of it in? Infants, brand new visitors of this ancient world.
We can look for these reminders from deep time as we traipse along Maine’s rocky coastline, recall how we all evolved from the same eroding crust.
Author bio: Laura Poppick is a science and environmental journalist whose stories have appeared in The New York Times, Audubon, Scientific American, and elsewhere. Her debut book Strata: Stories from Deep Time will be published by W.W. Norton in July 2025.