The architects of Columbia’s modern Northwest Tower, at the corner of Broadway and 120th Street, made good use of some beautiful stones. In their polished and swirling surfaces, they tell a story of the clash of continents and the processes by which mountains are made. Professor David Walker of the Lamont Doherty Earth Observatory leads us on Part 5 of the Columbia Geology Tour.
Coming next week: In a stairwell, the alpha predator of the Ordovician. (You can watch all of the videos on YouTube here.)
