Geology is pretty mind bending. Most of the bricks that built New York City, for example, were made with clay carried down by the ice sheet from Canada and deposited in huge amounts in the Hudson valley (back when it was covered in glacial lakes ~10,000 years ago).
Today, as humanity moved on from bricks to materials like steel and concrete, the massive brick factories are left abandoned and the excess bricks quietly erode back down into the earth:
I've seen enough of this comic at this point to think that it's very deliberate. I think the artist's goal is to create a spiritual successor to Peanuts