Earth Science Week 2017 - Wednesday (National Fossil Day™)

Happy Earth Science Week 2017!

Wednesday of Earth Science Week is celebrated as National Fossil Day™.  This summer, during our Out West vacation, we visited two large fossil sites the Mammoth Site of Hot Springs, SD and the Vore Buffalo Jump near Sundance, WY.

The Mammoth Site formed approximately 26,00 years ago when a sinkhole formed.  As the sinkhole filled with groundwater, it began to attract local wildlife (including mammoths).  Unfortunately for the mammoths, the sides of the sinkhole were steep and many mammoths fell into the shallow water where they were unable to escape.  Over time the sinkhole filled with sediment (and the remains of dead mammoths).  Overtime, the sediments surrounding the sinkhole eroded away and the former sinkhole was left behind as a hill!  This amazing site was discovered by accident in 1974 during excavation of a proposed housing development.  The importance of the discovery was recognized immediately.  Today the mammoth site remains an active paleontological dig with 61 separate mammoths being identified to date (along with other Ice Age fauna).

People in this photo give an idea of the scale of the site.

 

The arrows point out mammoth tracks in the sediment.

The goal at the Mammoth Site is to leave as many of the bones in place as possible.  On occasion some bones must be moved due to instability or the possibility of other more complete skeletons lying underneath them.  The site has a large overhead lift system to facilitate removal of bones when needed.

A mammoth skull wrapped in plaster for removal.

The fossils found at the Vore Buffalo Jump are much more recent than those of the Mammoth Site.  This site is also a sinkhole, but rather than accidental the deaths of the animals found here were intentional.  Over the course of 300 years (from about 1500AD - 1800AD) Native American tribes used the site to kill migrating bison by driving them over the edge of the sinkhole.  At least five different tribes used the location over time, as evidenced by stone projectile points found at the site.  While other buffalo jump sites have been located at cliffs, this is the only known use of a sinkhole for the purpose.  Less than 10% of the site has been excavated.

A building has been constructed over the active dig site at the bottom of the sinkhole.

The bones in the sinkhole are so jumbled that it is impossible to tell exactly how many buffalo died here.

 

What's with the ™ after National Fossil Day?  The National Park Service holds a trademark on the phrase National Fossil Day - while they allow use of the phrase, they do require that the trademark appear after the first use of the phrase in a document.

Earth Science Week 2016 - Wednesday (National Fossil Day)

Happy Earth Science Week!

Unfortunately I did not have time to write something new for today so I am re-posting an article that I originally posted in October 2014:

The Wednesday of Earth Science Week is designated as National Fossil Day.  National Fossil Day was first celebrated in 2010.  This celebration is organized by the National Park Service to "promote public awareness and stewardship of fossils, as well as to foster a greater appreciation of their scientific and educational values."

Happy National Fossil Day!

Like most states, Michigan has an official state fossil - the American Mastodon (Mammut americanum).  Over three hundred mastodon fossil sites have been found in Michigan, but only south of a line running west from Saginaw Bay.  No mastodon fossils have been found in Northern Michigan, nor any in the Upper Peninsula.

Mural depicting American Mastodons (Mammut americanum) -  Museum of Natural and Cultural History at Central Michigan University

Fossil American Mastodon Jaw -Museum of Cultural and Natural History at Central Michigan University

Not only does Michigan have a state fossil, but our official state stone is also a fossil - the Petoskey Stone.  Petoskey Stones are the fossilized remains of the extinct Hexagonaria coral.  Hexagonaria was a common colonial coral that lived in the warm shallow ocean that covered Michigan during the Devonian period (more than 350 million years ago).  Petoskey Stones can be found around the state, but are most common along the shores of Lake Huron and Lake Michigan.

An unpolished Hexagonaria - found in Shiawassee County, MI

The odds of finding a mastodon fossil are not very high, but with a little luck and a little time searching almost everyone will find a Petoskey Stone. 

A Hexagonaria coral "Petoskey Stone" on a Lake Michigan beach

So Happy National Fossil Day and happy fossil hunting!

Fossil Cockles

On Saturday (31 October), Shara and I spent part of the day at the Mid-Michigan Rock Club annual show.  We left with several sample to use in classroom presentations and for home display - sulfur from Maybee, MI, a chunk of native copper and quartz from the Upper Peninsula, and a large piece of gypsum.

My favorite purchase of the day was this...

Fossil Cockles from the Pliocene Epoch

These are fossils of an extinct species of cockle (clam) named Clinocardium meekianum.  The fossils are from a rock formation known as the Rio Dell Formation in coastal Humboldt County, CA and date to the Pliocene Epoch (5.33 to 2.58 million years ago).  Each individual shell measures approximately 2.5 to 3.0 inches (6.35 to 7.62 centimeters) across.  The group measures about 6 inches by 7 inches.

The underside of the sample

Rather than being used in classroom presentations, this specimen is destined for a shelf at home next to several other fossils.

Earth Science Week - National Fossil Day

Happy Earth Science Week!

The Wednesday of Earth Science Week is designated as National Fossil Day.  National Fossil Day was first celebrated in 2010.  This celebration is organized by the National Park Service to "promote public awareness and stewardship of fossils, as well as to foster a greater appreciation of their scientific and educational values."

Happy National Fossil Day!

Like most states, Michigan has an official state fossil - the American Mastodon (Mammut americanum).  Over three hundred mastodon fossil sites have been found in Michigan, but only south of a line running west from Saginaw Bay.  No mastodon fossils have been found in Northern Michigan, nor any in the Upper Peninsula.

Mural depicting American Mastodons (Mammut americanum) -  Museum of Natural and Cultural History at Central Michigan University

Fossil American Mastodon Jaw -Museum of Cultural and Natural History at Central Michigan University

Not only does Michigan have a state fossil, but our official state stone is also a fossil - the Petoskey Stone.  Petoskey Stones are the fossilized remains of the extinct Hexagonaria coral.  Hexagonaria was a common colonial coral that lived in the warm shallow ocean that covered Michigan during the Devonian period (more than 350 million years ago).  Petoskey Stones can be found around the state, but are most common along the shores of Lake Huron and Lake Michigan.

An unpolished Hexagonaria - found in Shiawassee County, MI

The odds of finding a mastodon fossil are not very high, but with a little luck and a little time searching almost everyone will find a Petoskey Stone. 

A Hexagonaria coral "Petoskey Stone" on a Lake Michigan beach

So Happy National Fossil Day and happy fossil hunting!

Earth Science Week - Wednesday

Happy Earth Science Week!

Today is National Fossil Day!  For today I thought I would share photos of some of the fossils in my collection.  Almost all of these fossils were purchased.  In many cases I do not know their origin.

Ammonites

Crinoid

Fern

Clams in a sandstone slab from the Mason Esker

Michigan fossil slab containing corals, shell fragments, bryozoa, crinoid stems, etc.

Cobble containing shells from the Mason Esker

Two trilobites and an ammonite

An unpolished Hexagonaria (Petoskey Stone)

"Petoskey Stones" Are Corals - An article from Nature Magazine (January 1942)

Last March I wrote an article about four fossils that had been found around Michigan.  One of the fossils that I wrote about was a "Petoskey Stone".  A Petoskey Stone is a fossilized colony of  Hexagonaria coral which lived in Michigan during the Devonian period (more than 350 million years ago).

Today I was looking through several old copies of Nature Magazine from the 1940s - not to be confused with Nature magazine.  Nature Magazine was published by the American Nature Association from 1923 to 1959 before being absorbed by the magazine Natural History. On page 46 of the January 1942 issue of Nature Magazine, I found this short article about the Petoskey Stone that I thought I would share.