Showing posts with label silver creek member. Show all posts
Showing posts with label silver creek member. Show all posts

Tuesday, February 4, 2020

Spinocyrtia (Platyrachella) oweni Brachiopod Fossil




This brachiopod fossil was found in the Silver Creek Member of the North Vernon Limestone of Clark County, Indiana, USA. It appears to be a Spinocyrtia (Platyrachella) oweni. It existed in the Middle Devonian Period.

Fossil was cleaned with ultrasonic cleaner.

Wednesday, October 19, 2011

Protoleptostrophia perplana? Brachiopod



This may be one of the largest best preserved brachiopods I have ever found, measuring over 5 cm in width. It was recovered from the Silver Creek Member of the North Vernon Limestone of Clark County, Indiana, USA and appears to be a Protoleptostrophia perplana? (Conrad, 1839). Originally, I thought this was a Megastrophia (Caster, 1939) in an earlier posting (CLICK HERE) but Dave at Views of the Mahantango blog pointed out that error.

Thanks to Kenny for cleaning the matrix off this specimen with sand abrasive cleaning.  See further down in this posting for before and after pictures of both sides.  It really is clean!





Wednesday, September 7, 2011

Aulopora Corals on Brachiopods


Included in this posting are pictures of Aulopora sp. coral fossils that colonized a brachiopod shell surfaces. It was attempted to clean the corals using sand abrasive air cleaning but that was with limited success.  The process took too long to remove matrix from the corals and at times would detach them from the shell.  This matrix of Silica Shale is some what harder than found on similar corals from southern Indiana.

As a comparison to the Silica Shale, the next two images are Aulopora sp. corals encrusted on a Spinocyrtia euruteines brachiopod from the Silver Creek Member, North Vernon Limestone of Clark County, Indiana USA.  This limestone matrix is softer and these Devonian fossils are composed of a reddish-purple colored material.







Here are some corals growing on a Spirifer brachiopod.





If you click on the last to pictures to see the full image size and then magnify portions of the fossil, one can see some micro coral colonies that formed on both sides of the shell.


Thanks to Kenny for doing some prep work on these fossils.  The Silica Shale fossils belong to Dave at the Views of the Mahantango blog.  Learn more at his blog post: CLICK HERE TO VIEW

Tuesday, August 30, 2011

Megastrophia (Silver Creek Limestone)


This brachiopod fossil is a nice find in that is over 5 cm in width.  It appears to be intact though needs to be cleaned with sand abrasive cleaning. Usually only the top half is found of this genus, Megastrophia.  These types of brachiopods might be one of the largest found in the Devonian layers around southern Indiana.

Fossil was found in the Silver Creek Member of the North Vernon Limestone of Clark County, Indiana, USA. This layer dates to the Devonian Period (Eifelian).

Hopefully, a posting of it cleaned up can be presented...




Tuesday, March 29, 2011

Tentaculites with Devonochonetes


Presented for your visual inspection, a Devonian hash plate from the Silver Creek Limestone of Clark County Indiana.  An intact Tentaculites with a lot of Devonochonetes brachiopods.

The Tentaculites is an extinct molluscs that lived in the Devonian and Silurian.  The ringed cone like shell is known as a conch.  Study of Devonian pyrite specimens from Germany alludes to the creature having tentacles.   So maybe they were like miniature shelled squids.  The next image shows the Tentaculites being about 1 cm in length.

Learn more about Tentaculitoids in the 1996 book Fossils of Ohio, Chapter 20 (pp.282-287) written by Stig M. Bergström.

This fossil is available for purchase on eBay CLICK LINK HERE.


On one side of this limestone block, is a cross section of a brachiopod with calcite crystals.


On the bottom of the plate are more remains of brachiopods plus this pygidium of a trilobite.  More that like it belonged to a Phacops.

View of top of plate:

View of bottom of plate:

View of one of the sides:


Sunday, February 27, 2011

Aulopora on Orthospirifer Brachiopod


One of the easier fossils to prep with sand abrasion cleaning are specimens from the Silver Creek Member, North Vernon Limestone of Clark County, Indiana USA.  I believe it is this layer of limestone that the county's large concrete plant uses to manufacture product.  This fossil is the Orthospirifer brachiopod and it has a nice colony of Aulopora coral growing on it.  The brachiopod and coral lived in the Middle Devonian Period.

Thanks to Kenny for cleaning this one up for me!





Thursday, July 22, 2010

Essroc Quarry - Speed, Indiana

Recently, I visited the Essroc Quarry in Speed, Indiana with a class of geology students from a local college.  The representative gave a us a presentation of the operations of the quarry which primarily produces cement for the North American market.  It is one of the largest cement manufacturing facilities in North America (the largest in the world may be in Germany).  North America is the third largest world producer of cement behind China and India.


The operations covers about 3000 acres (1214 hectares) with 1000 being the active quarry.  They estimate they have enough material at the current rate of consumption to produce cement for the next 150 years.  The quarry is large enough to be used by pilots as a visual navigation marker.

Cement is composed primarily of four ingredients: calcium, silicon, aluminum, and iron.  The plant uses the Silver Creek Member of the North Vernon Limestone to produce the limestone (calcium).  They obtain the silicon from the clay in the soil above the limestone. The rock material is obtained with Caterpillar front loaders and dump trucks and taken to the processing area.



The rock is then placed in the crusher to shape the rock into small pieces.  It is then mixed with silicon (clay), iron and aluminum.  I do not remember if he told us the source of the last two elements.  The rock is then broken down into a powder in one of the largest grinding apparatuses in the United States.  The material is then sent to a long rotating furnace heated to over 2500 degrees F (1370º C) to transition the limestone and silica clay to a hot mass called clinker  The steel drum furnace has to be lined with fire bricks because the metal drum can melt.  Coal is the fuel that heats the furnace (not sure if it comes from Indiana or Kentucky). The clinker is then put in a grinder to make the powder you find in Portland cement bags.


Learn about how to make cement in this video that Essroc created (Internet Explorer might be required to view).

A warehouse the size of about 1 acre stores the finished product.  It has the capability of loading 5 rail cars and many truck trailers simultaneously.  The finished products produced at the plant include BRIXMENT® Masonry Cement and Portland Cement.  In a side note: Portland gets its name from stone from the Isle of Portland off the coast of England.  It was named by its inventor (1824) Joseph Aspdin.  Learn more at the Portland Cement Association website.  They have a flash animation that documents the whole process.

Essroc Corporation is a good local citizen to Clark County providing approximately 150 jobs in their operations.  In the past, the former owner built infrastructure in the town of Speed including stores, a church, and park.  The 10 acre company owned and maintained park hosts the annual Art In Speed Park festival. This year (2010) the festival is August 28-29 from 10AM till 5 PM.

Extensive pollution controls are used control dust.  You can see in the image above of the golf course next to the plant is very green and not dust covered.  The area in the quarry and plant is also watered down with a water truck daily.   The company contributes to the tax base to help maintain roads and infrastructure used by company equipment.

Essroc is owned by Italcementi Group of Italy which has international holdings around the world.  The North American group as of 2009 consisted of 7 full cycle cement plants, 3 quarries, 1 grinding center, and 39 ready mix concrete plants with 1789 employees.  Their sales were 400 million Euros ($556 million) in 2009.


History
Speed, Indiana is named after former Louisville business man James Breckenridge Speed (1844-1912) who was president of Louisville Cement Company. According to The Encyclopedia of Louisville, after serving in the Civil War he worked for Louisville Hydraulic Cement and Water Power Company which was based in Shippingport at the the Tarascon Mill. In 1869, the name was changed and he became president. He was also involved in finance, coal, wool mills, railways, and telephone companies. After he died, the Speed Art Museum and University of Louisville Speed Scientific School were named after him.

Fossils
The Speed Limestone is known for several fossils: Hadrophyllum orbignyi, Bordenia knappi (Hall, 1882), and Eridotrypa bryozoan.  Interestingly, the Bordenia knappi was named by a local fossil dealer named George K. Greene in 1903 for a wealthy businessman/geologist William W. Borden whom Borden, Indiana is named after.  In my studies a lot of the fossils found in the Louisville area were named by people outside of the Louisville area this one is one of the exceptions.

Monday, July 5, 2010

Phacops Trilobite with Tentaculites

This plate was recently sand abrasive cleaned.  It revealed the cephalon of a Phacops rana (Green, 1832) trilobite with a Tentaculites (Schlotheim, 1820) in front of it.  The Tentaculites (Schlotheim, 1820) was in between a broken segment of Phacops (Emmrich, 1839) thorax.  Further exploration of the plate reveal pieces of unidentified bryozoan and Protoleptostrophia (Caster, 1939) brachiopod.

Matrix is Silver Creek Member of North Vernon Shale Limestone of Clark County, Indiana.  Fossils are from the Middle Devonian Period (Eifelian) dating approximately 397 to 391 million years ago.


Unfortunately, I did not take a picture of the plate before I cleaned it.  Curses!

Saturday, July 3, 2010

Enrolled Phacops rana


First two images of an enrolled Phacops rana (Green, 1832) trilobite fossil found in the Silver Creek Member of the North Vernon Limestone of Clark County, Indiana.  This fossil has been sandblasted though concrete like residue still remains in between thorax segments.  Creature existed in the Middle Devonian Period.  Nice size for this trilobite at about 3 cm wide.

Still not been able to determine if pygidium or cephalon exists on this fossil due to hardness of matrix.  Tried using the engraver some to expose more of fossil but conservative use due to fragile nature of fossil.


Fossil in plate before sand blasting.

Thursday, July 1, 2010

Aulopora on Protoleptostrophia/Devonchonete Brachiopods


This image shows an Aulopora (Goldfuss, 1829) coral growing across the surface of a Protoleptostrophia perplana (Conrad, 1839) brachiopod.  It is surrounding quite a few Devonochonetes (Muir-Wood, 1962) brachiopods. The plate was found in the Silver Creek Member of the North Vernon Limestone.  Specimens found in Clark County, Indiana.  Fossil creatures shown existed in the Middle Devonian Period (Eifelian).  Need to figure out a way to clean the matrix out of the little horn shapes.

Next picture shows the plate before it was sandblasted.  You can see quite a few Aulopora (Goldfuss, 1829) corals and some of the brachiopod surface.


Here is another piece of Aulopora (Goldfuss, 1829) my cousin will be sandblasting in the near future.  The Silver Creek matrix is some of the best to abrasively clean.  I believe this layer is the one used to create cement with.