Paleonet: marine fossils in coal

inselberg at inselberg at
Mon Oct 18 14:34:33 GMT 2010

Dr. James St. John asked:

“Hello - I am somewhat unfamiliar with the Carboniferous, 
so I wanted to ask how common it is to find marine
fossils in bituminous coal beds?

We've found productids, bryozoans, crinoids, and 
pectinacean bivalves on bituminous coal bedding planes 
in the Pottsville Group (Lower Pennsylvanian, Upper 
Carboniferous) in east-central Ohio, USA.

If these were washed in, I wonder why there's no 
accompanying sediments diluting the coal. Could 
marine organisms have settled upon a peat substrate
following a rapid transgression?

Any thoughts? Just curious!”

Christopher T. Baldwin replied:

“If you are dealing with coastal marshes (Think of the 
outer edges of the present Mississippi delta, or any 
other big delta for that matter) then you certainly would 
expect marine organisms. Many coal seams are terminated 
at their tops by a marine band that is composed of a 
carpet of large mussel-like shells (Carbonicola, etc.) 
These marine bands have high value as correlation tools.”

Dr. Robert A. Gastaldo and his coworkers have published a 
number of excellent papers that nicely illustrate what 
Dr. Baldwin writes about above. PDF files of these papers 
can be found on his home page at:

They include;

Pashin, J. C., and R. A. Gastaldo, 2009, Carboniferous of the 
Black Warrior Basin, in Greb, S.F., and Chestnut, D.R., Jr., 
eds., Carboniferous geology and biostratigraphy of the 
Appalachian and Black Warrior Basins: Kentucky 
Geological Survey Special Publication 1, Series 12,
p. 10-21.

Demko, T.M. and R. A., 1996, Gastaldo, R.A. Eustatic and 
autocyclic influences on deposition of the Lower 
Pennsylvanian Mary Lee Coal zone, Warrior Basin, 
Alabama: International Journal of Coal Geology. vol. 31, 
pp. 3-19

Gastaldo, R. A., T. M. Demko, and Y. Liu, 1990, Carboniferous 
coastal environments and paleocommunities of the Mary Lee 
coal zone, Marion and Walker Counties, Alabama. A Guidebook 
for Field Trip VI, 39th Annual Meeting Southeastern Section 
of the Geological Society of America, Tuscaloosa, Alabama. 
Geological Survey of Alabama, 139p

Finally there is:

Liu, Y., and R. A. 1992, Gastaldo, R.A. Characteristics of a 
Pennsylvanian ravinement surface: Sedimentary Geology, 
vol. 77, no. 3-4 , pp. 197-214.



Paul V. Heinrich
Louisiana Geological Survey
Louisiana State University
Baton Rouge, LA 70803

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