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, it must be named after a geographic locality).
Names with days:
Thursday Dolomite (named in Utah)
Friday Camp Gneiss (named in California)
Saturday Mountain Formation (named in Idaho)
Sunday Quartzite (named in Michigan & Wisconsin)
Names shared with automobiles:
Bentley Formation (named in Louisiana)
Buick Pluton (named in Missouri)
Cadillac Granite (named in Maine)
Chrysler Limestone (named in New York)
Dodge Shale (named in Iowa)
Ford Sandstone (named in Iowa)
Honda Formation (named in California)
Lincoln Sandstone (named in Kentucky)
Mercury Limestone (named in Nevada)
Renault Formation (named in Illinois, Indiana, Kentucky, & Missouri)
Tesla Formation (named in California)
Names used where you don’t expect them:
California Granite (named in New York)
Delaware Sandstone (named in Texas)
Florida Formation (named in New Mexico & Texas)
Illinois Granodiorite (named in Nevada)
Mexico Sandstone Member (named in Pennsylvania)
Michigan Basalt (named in Colorado)
Montana Breccia (named in Nevada)
Pacific Sandstone (named in Missouri)
Tennessee Sandstone (named in Arkansas)
Virginia Slate (named in Minnesota)
Various other names:
Bacon Limestone Member (named in Texas)
Bastard Limestone (named in New York & Pennsylvania)
Bathtub Formation (named in Arizona)
Battle Ax Basalts (named in Oregon)
Beer Bottle Rhyolite Member (named in Arizona)
Ben Hur Limestone (named in Virginia)
Big Butt Quartzite (named in North Carolina & Tennessee)
Christmas Tree Conglomerate (named in Utah)
Gene Autry Shale (named in Oklahoma)
Hell-to-Finish Formation (named in New Mexico)
Hurry-Up Sand (named in Pennsylvania)
Ice Box Shale (named in South Dakota)
Jackass Mountain Group (named in Washington)
Jackhammer Formation (named in California)
Janies Nipples Member (named in Idaho)
Kangaroo Formation (named in Colorado)
Moonshine Conglomerate (named in California)
Naked Girl Canyon Member (named in Arizona)
Orange Granite (named in Vermont)
Razorback Formation (named in New Mexico)
Rich Butt Sandstone (named in Tennessee)
Satans Kingdom Formation (named in Connecticut)
Six Flags Limestone (named in Texas)
Ticklenaked Formation (named in Vermont)
Troublesome Formation (named in Colorado)
And lastly, my favorite:
Noah Dolomite Member (named in Utah)
On a related note, I was once told a story by Dr. Doy Zachry about a grad student who was studying a sandstone bed that is informally known as the “middle Bloyd sandstone”, currently being considered to be formally named the “Parthenon Sandstone” by the Arkansas Geological Survey. The student did a measured section of this sandstone near the community of Limestone, Arkansas, and saw the opportunity for a fantastic, but confusing, name. He said to Dr. Zachry that they ought to propose the name “Limestone Sandstone” for this unit. However, Dr. Zachry had to shoot down that suggestion for the obvious reason.