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

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 16, 2025 - Diana Ionescu

Green vintage Chicago streetcar from the 1940s parked at the Illinois Railroad Museum in 1988.

Chicago’s Ghost Rails

Just beneath the surface of the modern city lie the remnants of its expansive early 20th-century streetcar system.

July 13, 2025 - WTTV

Blue and silver Amtrak train with vibrant green and yellow foliage in background.

Amtrak Cutting Jobs, Funding to High-Speed Rail

The agency plans to cut 10 percent of its workforce and has confirmed it will not fund new high-speed rail projects.

July 14, 2025 - Smart Cities Dive

Worker in yellow safety vest and hard hat looks up at servers in data center.

Ohio Forces Data Centers to Prepay for Power

Utilities are calling on states to hold data center operators responsible for new energy demands to prevent leaving consumers on the hook for their bills.

July 18 - Inside Climate News

Former MARTA CEO Collie Greenwood standing in front of MARTA HQ with blurred MARTA sign visible in background.

MARTA CEO Steps Down Amid Citizenship Concerns

MARTA’s board announced Thursday that its chief, who is from Canada, is resigning due to questions about his immigration status.

July 18 - WABE

Rendering of proposed protected bikeway in Santa Clara, California.

Silicon Valley ‘Bike Superhighway’ Awarded $14M State Grant

A Caltrans grant brings the 10-mile Central Bikeway project connecting Santa Clara and East San Jose closer to fruition.

July 17 - San José Spotlight