Stratigraphy, or study of rock or soil layers (strata), was originally introduced as a branch of geology. However, it is often applied in other disciplines, especially in archaeology and paleonthology. As an archaeologist (though not a field archaeologist), all I learnt about stratigraphy was taught from archaeological perspective. So I'm curious how the approach of other disciplines to stratigraphy differs from the archaeological. I'm especially interrested in geology - because it is the main and original discipline for stratigraphy, and because the geological time is very different from the archaeological time.
I know the basic principles such as law of superposition and principle of original horizontality are common. On the other hand, the time (hundreds or thousands of years x millions of years before present), materials on which stratigraphy is studied (sediments often created by human culture x rocks) and dating methods differ.
But how do these differences affect the "theoretical" methodology? That it is usually not possible to dig 100 million old strata with a spade is natural, but how about interpretation?
Is geological stratigraphy visualized with Harris matrix or something very similar too? Are there any special principles that usually apply only on very old strata? Or is geological stratigraphy simpler, so some archaeological stratigraphy rules don't apply? Is there any distinctions between various stratigraphic units (layers and cuts, or other distinctions)? If yes, which categories are usually distinguished?