I've seen about 'corduroy roads' on TV programmes talking of old back roads in America. The only book on geology I can recall reading was by a man with the surname Mountain! In Africa I and my men built access tracks across streams by using layers of rocks for the water to run between. My two literary efforts - African Odyssey and Black Dragon, Yellow Dragon (both on Kindle, by Eric Hayman) - are meagre compared to your extensive output. And I too am 'mature'.Yes, Hayman, I did think as I was writing it of 'coduroy roads', which I've had on my mind when including a bit of 17th century military engineering in one of my recent novels, but I wasn't sure how better to put it. It's not folded as the long hills are fairly even - much like overgrown ripples on a beach or lines of dunes in the desert, though of a flatter profile, having been worn down by 11,500 odd years of erosion. Heh, it's rekindled my interest in geomorphology, I might have to go see what recent books there are on the subject, since G.H. Dury 'The Face of the Earth' which was, if not cutting edge when I was at school still one of the better books. Being published 1959 it included the then newish studies of continental drift, and the effect of the weight of ice on the earth's crust.
Yup, I'm getting on in years.