A Geological Tapestry of
New York

Collections, location

Erosions, Beacon, NY
Kingston Crystal, Kingston, NY
Eye of the River, a mix of Kingston & Rocky Point, NY
Shore Beans, Rocky Point, NY

Mythical Relics, NY State stone from various locations

see below for geological details specific to each location.

Erosions Collection -Beacon, NY
Kingston Crystal -Kingston, NY

The rocks from the Hudson River's shores, first known as Mahicantuck by the Mahican and Lenape-Munsee tribes indigenous to the region—meaning "The great waters in constant motion" or “The river that flows two ways”—belong to the Austin Glen Formation.

This formation features alternating layers of shale and greywacke. Shale, composed of fine clay particles, is dark gray to black and smooth, while greywacke, a coarse sandstone, is lighter gray and rough. Shale layers are thin and sleek, contrasting with the thicker, sandpaper-like texture of the greywacke.

Ancient Origins of Hudson River Stones

Caitlin Lightfoot chooses stones from the deposits that are native to the shoreline and riverbed of Kingston and Beacon, NY along the Hudson River. Abundant shale and greywacke provide a palette of natural pigment which flows from deep charcoal black, to stormy grey blue, to lagoon blue grey. Red hues range from rusty and sanguine to a plummy, liver quality and deep browns. The stones can have variations from related colors or be striated with white lines of calcite or quartz. This coloration is a result of their layered formation, as they are sedimentary rocks. Textural differentiation ranges from dense, smooth matte to a fine coarse grainy feel.

  • The rocks collected on the shores of the Hudson River (First called the Mahicantuck by the Mahican and Lenape-Munsee indigenous tribe of the region, meaning ‘The great waters in constant motion’ or ‘The river that flows two ways’) in both Beacon and Kingston are part of a rock formation called the Austin Glen Formation. This formation is made up of alternating layers of sedimentary rocks called shale and greywacke. Shale is made up of fine grained particles of clay, whereas greywacke is a general term for a dark gray sandstone made up of much larger particles of sand. If you were to go up to an outcrop and compare the layers, the shale layers are generally a darker gray or black color and feel very smooth to the touch, composed of lots of very thin layers, while the greywacke layers are thicker, slightly lighter gray and feel more rough, like sandpaper.

    At first glance, these may just look like any other gray rocks, but they went through quite a lot before ending up on the shores of the river and into your hands. The sediments that make up these rocks are very ancient clay and sand particles - they tumbled down off the shores of a mini continent as mini sediment avalanches into a deep ocean over 450 million years ago. Back then, there had yet to be the Hudson River, humans, dinosaurs, any type of land animals, trees, or even the continent of North America as we know it. Earth’s top layer, the crust, is broken up into chunks called tectonic plates, and when these plates move around the surface of the Earth, they form all sorts of things like mountains, volcanoes, and most importantly, different continents! Almost 500 million years ago, there was a mini-continent called Avalonia off the coast of ancient North America, called Laurentia.

    In between the two, there was a deep ocean, and lots of sediments were constantly being weathered off of Avalonia by water, wind, and other geologic forces always at work. Many of them made their way out into the ocean through a gradual slow journey, with the smallest clay particles making it the farthest and settling in thick layers of soft mud at the very darkest depths of the ancient ocean. But in between these calm, slow periods of deposition there were quick bursts of small sediment avalanches underwater, launching those larger sand particles farther out into the ocean and settling on top of the soft muds. Geologists believe that these were caused by earthquakes on or near the mini continent, causing quick bursts of sediment movement into the water from the land. Millions of years later when Avalonia collided and merged into Laurentia, these layers of mud and sand were compacted into rock and

    pushed up to the surface where we now can see them on dry land. The soft muds compacted into the shale layers, and the underwater avalanches compacted into the coarser greywacke layers called turbidites.When you look at and feel these stones, you will notice thin white lines that look like they were drawn by the very precise, steady hand of an artist - but no. These formed later on, after the sediments had already been deposited and compacted into rock. First, the rocks fractured from various types and directions of stresses, forming tiny open spaces in the rock. These open spaces eventually were infiltrated by water that seeped in between the different particles of sand or clay of the greywacke or shale. When the water went away, it left behind minerals that precipitated into crystals over time, filling these empty spaces with quartz. The different intersecting lines each represent a different geologic event - possibly millions of years apart or long - that put stress on the rocks, forcing them to fracture open towards the direction of the least stress.

    Another notable feature of these stones is their smoothness. These sculpted, smooth surfaces are a result of countless hours of weathering, where waves tumbled other rocks and sediments against each other over and over again before being dropped by a lowering tide for the last time on the shores of the Hudson River where they were collected. The particles of sand, silt, and clay that were chipped off one by one by Earth’s persistent hands are now who knows where - maybe still floating in the Hudson, out on the continental shelf in the Atlantic Ocean, or just sitting on a beach downriver. Maybe even one day they will make their way out to the bottom of a different watery abyss and turn into a brand new rock millions of years into the future - where someone might pick it up and wonder about its ancient origins. Each rock tells its own story that anyone can decipher if they have the knowledge. Remember this next time you pick up ‘any old gray rock’ by the river.

    © Becky Nesel, Geologis

Geology of the
Shore Bean Collection
Rocky Point, NY

The softly rounded stones of the Shore Bean collection come from the north shore of Long Island, in the town of Rocky Point. Long Island was formed at the end of the last ice age, which began during the Pleistocene roughly 2 million years ago. During this time, multiple ice sheets expanded over and later retreated from large swaths of North America. In colder periods, the ice sheets would advance over the landscape in a blanket of ice that reached 2 miles thick in places. In warmer periods, the glaciers would partially melt - geologists call this a retreat. These advances and retreats happened constantly during the Pleistocene, like a dance of ice moving back and forth across the continent. The most recent ice sheet, the Laurentide Ice Sheet, is what we see evidence of in modern day Northeastern US. We can read the landscape like a story, the ice sheet leaving behind clues from its last advance and its last retreat.

  • At the Laurentide’s last retreat, it created Long Island. When it was advancing during the last cold period about 20,000 years ago, it scraped along the land like sandpaper. Any soil, rocks, sediments, plants, or trees that were in its path were uprooted, crushed, ground down into clays and pebbled and gravel. Some larger chunks of rock stayed intact and hitchhiked in the glacier, then dropped in new places where they would confuse geologists thousands of years later (glacial erratics). This big mess of dirt and rock was pushed forward by the advancing ice like a giant bulldozer, the front edge of the ice sheet collecting remains of prior landscapes from different parts of the region.

    As this last cold period transitioned into a warm one, the ice could no longer remain in its solid state. It began to melt, and no longer could push forward the giant pile of dirt and rock. Think of this like the driver of a bulldozer suddenly backing up the bulldozer, and leaving behind the pile of whatever was just being pushed forward. That ‘pile’ is the terminal moraine we now call Long Island.

    Now think about all of the land that the ice had scraped over during its advance southward, all of the dirt and sand and rocks that it collected in its travels. All of this earth had now been dropped in this huge pile in an unfamiliar geological setting. The rocks in this pile do not represent the geologic history of the place they now find themselves in. If you were to look at a piece of bedrock on a hike up a mountain for example, you would be able to put together some kind of geologic history of that place based on what the rocks told you. On Long Island, this possibility goes out the window because of the origin of the rocks found here. That’s partly what makes the Bean collection so special. There’s this feeling of mystery that comes with the stones foraged from Rocky Point. Did they come from a granite rock formation, or basalt, or quartzite? What part of the Northeast did they come from, and how old are they? What would they be able to tell us about their long journey if they could talk?

    © Becky Nesel, Geologist