What are Earth's oldest volcanic rocks, and how did they form? Today, we'll explore the seafloor 3.8 billion years ago through dark basalt rocks in Nuvvuagittuq, northern Quebec. Along the way, we'll earn a green belt in geology, rest our heads on volcanic pillows and journey to the deepest spot in the modern ocean.Extra Credit: Try to find dark black basalt in a building or countertop near you.