Over 400 million years ago the continents of (what is now known as) Europe and North America collided. With that immense force, the Appalachian Mountain range was pushed up from the impact. At the same time, an increase in global temperature melted the ice caps enough to significantly increase the sea level. To the west of the mountains, including what is now Central and Western New York ,the land flooded with a shallow sea. Marine life thrived here as fresh water from the mountains carried sand and nutrients into this sun-saturated saline ecosystem. Regular deposits of sand, silt, and mud from the mountains created the varied rock layers characteristic of the Finger Lakes Region. Sand from the eroded mountains was packed in layers and under high pressure to create sandstone. Organic-rich mud, probably deposited along the ocean floor by seasonal floods became the soft and brittle shale stone. Its organics now decayed into natural gas, the centerpiece of hydraulic fracturing mining (or fracking). Crustaceans, feeding from the nutrient-rich estuaries, amassed in these shallow oceans. The sheer volume of their colonies over time is measured in the bountiful limestone layers that cap the region’s waterfalls. Limestone is comprised of the minerals left from their shells. Salt from the occasional evaporating of the sea resulted in the massive salt deposits that created the salt mining industries that grew up around Seneca and Onondaga Lakes.
Uplift and river valleys
Around 360 million years ago, sea levels began to decline, and the land that was for millions of years covered in a shallow ocean began to uplift. By 100 million years ago, the inland sea that once covered New York would have mostly disappeared. The new land uncovered began to form a mesh of river valleys, most of which flowed south-to-north, and one valley that flowed west-to-east, carrying the drainage out to the ocean.
Ice age carving
About 2 million years ago a series of ice ages resulted in the massive deposits of snow across the northern continent. The snow packed up for miles and compressed into massive ice sheets called glaciers. The river valleys of New York filled with ice and as the glaciers slowly moved, they gouged out the existing valleys deep into the bedrock, carving out basins which would become the Finger Lakes and the Great Lakes.
As the glaciers receded, they left huge holes across the state, that filled instantly with their melt-water. The south-north flowing valleys were deepened by the glaciers and become the Finger Lakes. The west-east flowing valley that emptied to the north became Lake Ontario and the St. Lawrence River. The lakes still retain their directional flow from pre-glacial times.
“In your hands
The dog, the donkey, surely they know
They are alive.
Who would argue otherwise?
But now, after years of consideration,
I am getting beyond that.
What about the sunflowers? What about
The tulips, and the pines?
Listen, all you have to do is start and
There’ll be no stopping.
What about mountains? What about water
Slipping over rocks?
And speaking of stones, what about
The little ones you can
Hold in your hands, their heartbeats
So secret, so hidden it may take years
Before, finally, you hear them?”
Marine sediments were deposited in the area by a deepening sea whose shoreline gradually moved to the east during the Middle Silurian. Above the beach and the shallow off-shore Grimsby and Kodak sandstones there is the fine-grained green Maplewood shale. It contains a few marine fossils. Following this is an unusual rock; a sedimentary iron deposit. Though thin here, it is contemporary with deposits laid down in several areas of the United States.
The “basement” rock beneath the Paleozoic sediments was exposed in a core from a deep well (3,078 feet) drilled in Rochester before the turn of the century. It was reached in a search for gas in the Ordovician rocks. This local “basement” rock is a quartzite, and its relations to different kinds of basement rock elsewhere in Western New York are obscure; few similar records exist.
The bedrock in Western New York consists of a succession of lower and middle Paleozoic sediments-chiefly shales but including prominent beds of dolomite, cherty limestone and thick bedded sandstones which are weather resistant and tend to form cliffs.
The sediments in Western New York were the debris from the erosion of older rocks southeast of this area, probably along what is now the Mid-Atlantic Coast of the United States. Igneous and metamorphic rocks, as well as sedimentary rocks, supplied fragments of quartz and feldspar and other common minerals. The clay minerals that formed shale in Western New York largely resulted from the chemical breakdown of feldspar minerals during weathering and erosion of the source area uplands.
“I have always felt insignificant while thinking in-terms of Deep time, I have always dreaded the fact that however much we struggle, the monuments we build to keep us alive even after we are gone will be erased just in a snap of finger or a blink of an eye and we will be no more.”
― Allan Amanyire
“Geology gave us the immensity of time and taught us how little of it our own species has occupied.”
― Stephen Jay Gould,