Driving long distances on the interstate is like blue water cruising without an autopilot or auto steering – lots of detailed attention required and boring as hell.
Driving down I-85 southwest through North Carolina and South Carolina, I noticed a couple of mountain peaks (about 1,000 feet high). They were conical shapes that appeared to be all alone so I wondered whether they were extinct volcanoes. I googled geological formation of Kings Mountains, SC, and discovered that in fact they were volcanic in nature. The rock in this north-south band of terrain (technically the Caroline terrane) is considered exotic rock because it is different from the types of rocks on either side. However, that didn’t mean that there have ever been volcanoes in NC/SC. When the land mass that would become Africa split off from the land mass that would become North America, about 400-500 million years ago, there was significant volcanic activity on the west side of the African land mass. The Carolina terrane split off and drifted on the molten mantle over the next 100 million years moving to the west, sinking about a mile and a half into the sea that would become the north Atlantic, and gathering a significant amount of ocean sediment. It crashed (over a period of 7-8 million years) into the budding North American continent, riding up onto the seabed to connect with the existing area. Erosion of the sediment exposed the volcanic rocks while the sediment washed to the ocean to form the coast of the eastern North American land mass, i.e. all the land between the Kings Mountains and the ocean today. All of this was accomplished by about 2.75 million years ago. Cool!
The result was a highway with sharply rising and falling ridges that really exercised the engine and transmission.