sedimentary

Can you find the unconformity?

An unconformity is an erosional or non-depositional gap in the geologic record. They typically form when an older layer is subject to a period of erosion before the deposition of new sediments.  This road cut near Payson, Arizona shows a pretty cool unconformity. Can you find where it is? Check the jump below to see… Continue reading Can you find the unconformity?

petrology, sedimentary

Geo Lingo | The Language of Geologists

Does it ever feel like geologists are speaking a different language? With so many different terms to describe and categorize rocks, learning the lexicon of a geologist can be a bit daunting. To help learn some basic geo lingo, here’s a (far from comprehensive) guide of some of the most important classification and terms geologists… Continue reading Geo Lingo | The Language of Geologists

sedimentary

Ooids • Sedimentary Spheres

While these dark gray spherical clasts could be mistaken for some type of fossil, they’re actually ooids, which are chemically precipitated sedimentary grains. Ooids form around a nucleus of a mineral grain or shell fragment. Concentric layers composed of calcium carbonate precipitate out and progressively coat the nucleus, forming a pattern almost like tree rings.… Continue reading Ooids • Sedimentary Spheres