The Geology of New England Fieldstone by 4 Nichols

What is a fieldstone?

Simply put a fieldstone is a rock that is found in a field, though that description hardly does it any justice. The story of the fieldstone is much longer, spanning millennia, and much more exciting than an inorganic chunk of minerals just sitting in a field. The story of the fieldstone is an epic.

A fieldstone is actually a patient remnant of a time long past, a time-traveler from an earlier Earth. This polished stone that you can now reach out and touch is, in fact, a wandering nomad that has seen hundreds of millions of years and earthly forces that almost defy comprehension. What if this stone, that was forced to leave the earthen embrace of Mother Nature, could actually tell you its story?

Forged in a sea of flames, crushed by shifting continents, and buried for eons, the fieldstone was then snatched from its home by an unimaginable quantity of ice restlessly meandering across the globe. Countless years have passed this stone by as it drifted across yet-to-be-named lands in solitary exile before it was finally abandoned in a field, forgotten by the forces of nature that had formed and displaced it.

Early New Englanders encountered this tired, little stone while trying to clear suitable farmland often collecting the top stones and relegating them to the stone walls for which New England is famous. Year after year, the farmers continue to battle the relentless stone and the walls grow. The fieldstone’s rough, unfriendly exterior hides a beautiful story waiting to be told.

Now, in your hands, it awaits the next chapter of its journey. From an ancient world, to your home today, this stone has an amazing story to tell, all you need to do is listen…

The story of the Fieldstone is a story of artistry.

The common fieldstone of New England is widely labeled as an unremarkable and rounded stone that can be found littering the New England low-lands and valleys. Traditionally these stones have been stacked into stone walls as a by-product of land cultivation, and, more recently, have found further usage as pieces of art and architecture. Would you like to know more?

Comparing our lifespan to the stones under our feet

To begin to understand the scope of a New England fieldstone, a simple fact of scale must be considered. We, as human beings, measure our lives in years, where as the stones measure their lives in millions of years. Just as there are different types of people out there, there is also a wide assortment of different stones as well. In a broad sense, stone can be divided up into three large categories: Igneous, Sedimentary, and Metamorphic.

Igneous stones are usually the result of liquid magma making its way into, or on top of, the Earth’s crust where it then cools and hardens into solid stone. Typical examples include granite, basalt, and diorite in New England. Sedimentary stones are usually the result of solid stone at the Earth’s surface that is worn down into sediment (boulders, stones, sands, and mud) through various processes of erosion, deposited, and then “cemented” back into a new type of stone over vast periods of time. Fieldstones, in a broad sense, represent the initial transformative step of bedrock turning into larger sediment fragments. Common sedimentary stones are sandstone and shale. Lastly, there are the metamorphic stones. These stones are often the hardest to describe, but make for some of the most beautifully complex fieldstones. Metamorphism occurs when solid stone (of any type) is subjected to extreme heat and/or pressure allowing the minerals in the stones to remobilize and reorganize. These conditions are commonly associated with the movement or collision of landmasses, which New England experienced in its geologic history. Common metamorphic stones include marble, schist, gneiss, and quartzite.

Geologic Multi-car Pile-up

If you ask a geologist about New England geologic history to describe the local bedrock they will often use the word is “complex” at least once. In the case of our unassuming fieldstones, life often did not begin in the fields from which they emerge today. Science tells us that these stone had much earlier beginnings in the hot, molten innards of our planet. Billions of years ago, it is theorized that a super-heated, infant-staged Earth began to cool slightly where it met the vast, coolness of space, creating a thin “skin” of stone that concealed the super-heated interior. The Magma that still exists under this crust is, after all, liquid stone. An apt analogy would be to consider water and about how water, when cooled, begins to freeze.

As one might expect, these cooling slabs of crust began growing and shifting. These shifting masses began colliding with their neighbors, kind of like geologic car-crashes spanning billions of years. A combination of the cooling process and a series of geologic orogenies, or “car-crashes”, gave rise to the stone that would eventually become common fieldstone.

The stone that lays under New England is the site of a truly massive such crash. Imagine the bedrock of New England as a rail-road crossing. Four actors: the Laurentian “Locomotive”, the Taconic “Pick-up Truck”, the Acadian “Sedan”, and the Alleghenian “Cement Truck” represent the land masses.

The scene starts 440 million years ago with the Laurentian Locomotive (proto-North America) slowly lumbering down the rails. It is big, heavy, and firmly anchored to the ground below it. Suddenly, the small Taconic Pick-up (a small volcanic island chain) crashes into the right side of the massive Laurentian Locomotive. As you might imagine, the ensuing carnage of the collision is largely one-sided, but some damage is taken on both sides.

This collision of land masses was followed by two more collisions. The Acadian Sedan collided 350 million years ago, plastering the micro-continent of Avalonia on top
of the previous collision, followed by the Alleghenian Cement Truck 25 million yearslater and lasting upwards of 50 million years. This collision was the event that created the Appalachian mountain range (thought to have once been as expansive as the Himalayan mountains are now) as Euramerica (N. America) collided with Gondwana (Africa). This event created the supercontinent of Pangaea, where all the earth’s landmasses were connected to one another until its eventual separation that began roughly 180 million years ago and is still occurring today. The Appalachian mountain range still stands, but is but a shadow of its former self, as tens of millions of years of weathering has nearly washed them away.

The Big Freez(es): Ice Ages vs. Glacial Periods

It is believed that we are still in an Ice Age, though we are in a warmer period (interglacial) within this larger thermal cycle. This large cycle of global freezing and thawing is relatively recent when compared to the continental shifting that is responsible for forming the continents that we know today, but when compared to the history of our own species, the scope of ice ages still dwarf our own combined histories. During the most recent period of glaciation, it is thought that most of New England was covered with sheets of ice that was often thousands of feet thick. Evidence of this hinted at by peculiar landmarks (such as Cape Cod and Long Island) and grooves cut into solid bedrock (Glacial striations). These relentless, crushing, slow-moving sheets of ice scoured the land of most anything that wasn’t bedrock. Even the bedrock was not safe as mountains and valleys alike were forced to fracture and give up pieces of themselves to grinding advance of the ice. A period of warming occurred about 12,000 years ago, causing the receding of the ice back to its present locations near the poles. The glaciers that had long covered much of the continent of North America began to melt, recede, and drop all of the earthen material and stone that it had been carrying in its icy mass.

How the Stones Came Down from the Mountains

Stones and debris of all shapes and sizes were dropped at random about the landscape as solid land emerged from under the weight of the crushing presence of the retreating ice sheets. Stones that were dropped on hills and mountains were methodically brought to valleys and lowlands by gravity and the force of moving water. Thousands of years of rainfall, seasonal freezing/thawing, and winds placed fieldstones on the fields that farmers would eventually use to grow food.

The Rugged Holdouts

Humans are thought to been manipulating fieldstones in New England for thousands of years now, from stone tools to stone caves to property-bounding stone walls. As humans began cultivating the land for food production, the fieldstones have been the bane of their efforts of plowing and harvesting, often damaging or disabling equipment. They began making stone walls out of them and, as the yearly freeze/thaw cycle would bring more stones to the surface, the walls and piles of fieldstone would expand.

Sliced, diced, and made to look real nice!

It wasn’t until recently that humans have begun to truly realize the inner beauty of the fieldstones. Still sought after as a quaint building material, much of the beauty of the fieldstone lies hidden inside. The interior displays the complexities that hint at the struggles of each individual stone. Some sparkle, some shine, some are very colorful. Some have striations while others are smooth. Some are rounded and others pointed. Each stony fabric and texture seen on the surface of a food slab is an epic record of the creation of that particular field stone. What sort of story does your Charcuterie Board, Coaster, Or Bowl whisper to you?