Bearded Geology

A new project I've been working on is now on the blog: the Arkansas Paleozoic Stratigraphy Database . This is a searchable database of the Paleozoic lithostratigraphic nomenclature in Arkansas with some related information. Within this database, you can search for stratigraphic names that not only are currently in use, but names that are now abandoned and replaced, as well as some that have recently been proposed. For each name you can find its age, any sub-divisions, proper usage as used by the USGS and AGS, historical usage (including past and present names), type locality or type area, type section location (if available), primary reference section location (if available), geographic distribution, etymology of the name, and citation of the original publication the name was used in. Also included for each name is a downloadable stratigraphic chart (PDF file) of either the Ozark or Ouachita/Arkansas River Valley region (whichever the unit is best exposed in) that illustrates the s...

While I've been doing some reading and writing for my PhD comps exam, I've tangentially discovered that the term thagomizer  is not in the 783-page Glossary of Geology  (5th edition, revised 2011). I was under the assumption that the term, coined in Gary Larsen's The Far Side comic strip for the spiky bits of a Stegosaurus' tail, has entered mainstream usage. However, it appears that it hasn't quite attained formality in scientific literature, much to my dismay. (image credit: ©Gary Larsen/ Wikimedia ) The Glossary of Geology includes several anatomical names used in paleontology (e.g. orbit, tibia, glabella, and gizzard), but the thagomizer didn't make the cut. Although it has recently become used in the scientific literature ( Costa and Mateus, 2019 ). This got me wondering if there are any terms used for the bony plates that protrude from the Stegosaurus' back. Unfortunately, I have not found any such endearing name for these like the t...

Geologists frequently use the term dolomite to describe both the mineral and the carbonate rock that is comprised of that same mineral. However, I find this to be unnecessarily confusing, especially since a clear distinction between calcite and limestone is recognized. So, I've dug up some history to the term dolomite . In 1768, Swedish natural scientist and “father of modern taxonomy”, Carl Linnaeus (later known as Carl von Linné), briefly described a type of rock he called marmor tardum , translated as slow marble . Marmor tardum , Linnaeus says, is a white marble that is as hard as quartz, but slowly effervesces potentially describing a dolomitized marble. Italian geologist, Giovanni Arduino, also described a marble in 1779 that has been considered to be dolomitized. However, it wasn’t until 1791 that a more complete description of dolomite was published by French geologist Déodat Gratet de Dolomieu, who described dolostones in the Alps (a region then called County Tyrol) ...

The USGS has a great website for searching stratigraphic names and I've found some names that are a little different. I've listed some of the most interesting ones below. Note that many of these are from the western states, and there's a reason for that. Names of lithostratigraphic units (groups, formations, members, and beds) must named after a geographic locality, such as a county, town, river, or mountain, per the nomenclatorial rules set forth in the North American Stratigraphic Code . Many of the geographic localities in the eastern US are more puritanical, if you will, from early European settlers, while the western states settled in the mid- to late-nineteenth century were named more loosely. Also, note that not all of these names are currently in use, some of these names may have been abandoned in favor of another name(s) and others may have been proposed, but not formally accepted for one reason or another (e.g. it must have sufficient reason for naming the unit,...