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.

Aulopora on Protoleptostrophia Brachiopod

This image shows an Aulopora (Goldfuss, 1829) coral growing across the surface of a Protoleptostrophia perplana (Conrad, 1839) brachiopod.  Two other brachiopods shown in the top left are probably a Spinocyrtia or Devonochonetes. 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).

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

This last picture shows the plate after sandblasting.  The cleaning was focused on the Aulopora (Goldfuss, 1829) coral growing on the brachiopod.

Protoleptostrophia perplana Brachiopod

Half of an internal Protoleptostrophia perplana (Conrad, 1839) brachiopod found in the Silver Creek Member of the North Vernon Limestone.  Specimen found in Clark County, Indiana.  Brachiopod existed in the Middle Devonian Period (Eifelian).

While this fossil is not complete, features I like are the muscle scars and exposed hinge teeth. It might be mixed in with other brachiopod fragments of Chonetes and Sprifier. 

The Silver Creek Member ranges 0-9 meters in thickness through out Clark County.  Described by (Campbell & Wickwire, 1955) as "homogeneous, fine-grained, bluish to drab or gray, argillaceous, magnesian limestone". I find it to be a light gray to whitish in color and quarried for cement.  Maybe it is the reason Cementville exists with the Essroc plant in Clark County.  It was named by C.E. Siebenthal in the 1901 Indiana Department of Geology and Natural Resources Annual Report 25. 

Sources for identification:

Formations of Ordovician, Silurian, and Devonian Rocks in the vicinity of Hanover, Indiana Compiled by Guy Campbell and Grant T. Wickwire - January 1955.

Picture on fossilpictures.wordpress.com web site.  Especially picture located lower left corner (click to enlarge).