In the last world, the early surface had some ore bearing rocks on them. Yellow ones with ochre, brown ones with heavy earth, &c.
I have not found anything like that this world. And the wiki seems to be missing them, as well. I only see ores you can get by mining in cave systems, no surface rocks.
Were ore-bearing boulders on the surface removed? Or are they around, but I just haven't looked hard enough, or otherwise lack the skill?