Excavations Unlock New York City’s Dramatic Geologic Foundation

A decade of subterranean excavations on the Third Water Tunnel, the Second Avenue Subway, and the Long Island Rail Road’s East Side Access Project has provided geologists with unprecedented access to New York City’s physical structure.

1 minute read

February 22, 2014, 9:00 AM PST

By James Brasuell @CasualBrasuell


Sam Roberts provides a glimpse of the excitement experienced by geologists in recent years as they’ve explored the subterranean levels of New York City. Quoted int he article is Tony Hiss, the author of The Experience of Place, who describes what’s so exciting about New York’s foundation: “New York’s deepest and darkest secret, its oldest and most violent and previously only vaguely glimpsed history is finally coming to light — the schist that formed three-quarters of a billion years ago, when colliding continents compressed an ancient ocean; the even more elusive amphibolite, three times harder than concrete, that’s a slow-cooked remnant of islands as big as Japan off the New York shoreline.”

New York City's geology has also had a marked impact on the country’s most famous real estate market: “The application of that theory illustrates why skyscrapers historically sprouted downtown and in Midtown, but not in between. The bedrock — the formidable Manhattan Schist on which their concrete foundations rest — is closest to the surface in those two areas, though, nowadays, the technology exists to build almost anywhere.”

Monday, February 17, 2014 in New York Times

portrait of professional woman

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban Planner

Cover CM Credits, Earn Certificates, Push Your Career Forward

Aerial view of town of Wailuku in Maui, Hawaii with mountains in background against cloudy sunset sky.

Maui's Vacation Rental Debate Turns Ugly

Verbal attacks, misinformation campaigns and fistfights plague a high-stakes debate to convert thousands of vacation rentals into long-term housing.

July 1, 2025 - Honolulu Civil Beat

Logo for Planetizen Federal Action Tracker with black and white image of U.S. Capitol with water ripple overlay.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

July 2, 2025 - Diana Ionescu

White and purple sign for Slow Street in San Francisco, California with people crossing crosswalk.

San Francisco Suspends Traffic Calming Amidst Record Deaths

Citing “a challenging fiscal landscape,” the city will cease the program on the heels of 42 traffic deaths, including 24 pedestrians.

July 1, 2025 - KQED

Google street view image of strip mall in suburban Duncanville, Texas.

Adaptive Reuse Will Create Housing in a Suburban Texas Strip Mall

A developer is reimagining a strip mall property as a mixed-use complex with housing and retail.

7 hours ago - Parking Reform Network

Blue tarps covering tents set up by unhoused people along chain link fence on concrete sidewalk.

Study: Anti-Homelessness Laws Don’t Work

Research shows that punitive measures that criminalized unhoused people don’t help reduce homelessness.

July 6 - Next City

Aerial tram moving along cable in hilly area in Medellin, Colombia.

In U.S., Urban Gondolas Face Uphill Battle

Cities in Latin America and Europe have embraced aerial transitways — AKA gondolas — as sustainable, convenient urban transport, especially in tricky geographies. American cities have yet to catch up.

July 6 - InTransition Magazine