Google's Geology Logo and Nicolas Steno's Birthday

Once I saw what was Google's new image logo for today I knew I had to write a post on it. It's all about Geology! More specifically it's referencing a famous Geologist and the founder of modern stratigraphy, Nicolas Steno. As it is is 374th birthday today.

I'm sure most of you reading this have no idea who Nicolas Steno is or stratigraphy or why it is important, but nonetheless. Basically Steno came up with the defining principles in the science of stratigraphy which are; the law of superposition, original horizontality, lateral continuity, and cross-cutting discontinuities. I'll give a brief overview of what each means.

The law of superposition basically means that at the time that any given stratum (layer of rock) is being formed, nothing above it existed. The law of original horizontality means that any given strata was once horizontal to the horizon even if it is now titled or perpendicular. Later continuity means that a given strata's material was continuous across earth unless barriers were present. And lastly, the law of cross-cutting discontinuities means that if a body or discontinuity cuts across a given strata it happened after that strata was formed (and therefor is younger in the geologic timescale).

Happy Birthday to Nicolas Steno!