Definition relative dating geology
If you need more help with geologic time or terminology, check out these resources.
Colorado's geologic history is as complex as it is fascinating.
The entire Mesozoic Era (295 Ma long) shot by in under an hour, the dinosaurs departed just 20 minutes ago (thank goodness), and we've been comfy and relatively ice-free for only a mere 0.2 seconds.
A healthy human female can expect to live just under 2 milliseconds in a developed country.
As we come up on major divisions along the geologic timeline, a brief "About Time" header will summarize what event or fossil record breakpoint ushered in the upcoming division and show how it's subdivided.Over 50 Ma, an entire mountain range like the Ancestral Rockies can rise up and vanish.The pink feldspar bands in the severely deformed metamorphic rock at right (a mylonite from the Homestake Shear Zone in the northern Sawatch Range) show the kind of internal folding you'd expect from warm taffy, but this rock didn't actually melt.The wavy fabric indicates solid flow at mid-crustal temperatures of 400-500C.To recast barely conceivable geologic time intervals in a more familiar format, they'll also appear from time to time as military hours in a single 24-hour day (and all-nighter) of creation beginning at the planet's formation and ending with the here and now.
This geologic overview focuses primarily on the Colorado Rockies and the Colorado Plateau, but adjoining portions of Wyoming, Utah and the High Plains as far east as the Black Hills of South Dakota also have important and related stories to tell.