The Ashlock Formation:
A Paleo Class Project by Rachel S. Galvin
The Ashlock Formation from which I gathered my fossil collection is located in central Kentucky just outside of Richmond. It is home to an abundance of marine fossils including impressive whole, three dimensional brachiopods, multiple types of bryzoans, bivalves, crinoids, cephalopods, and gastropods. The unit itself is a thin to thickly bedded limestone of Ordovician age with shaly partings...perfect for fossil hunting! Due to an excessively acidic vinegar solution purchased form the local Wal-Mart, on the advice of an "all-knowing" graduate student, fossils initially collected, and of course the most impressive, were sadly destroyed. The following images, however, accurately relay the types of fossils preserved in this particular outcrop of the Ashlock Formation.
Local day-laborers hired from the Winchester Road location. Good workers but unfortunately had to be fired for hanky-panky on the job.
Specimen Identification:
All specimens in this collection (which are listed in italics) are from the Animal Kingdon and they are classified taxonomically. Though each category may not be known for all samples, a guideline to the taxonomic divisions are as follows (note the color of each division for future reference):
Kingdom
Phylum
Subphylum
Class
Subclass
Order
Family
Subfamily
Genus
Species
Specimens:
Stenolaemata
Trepstomata
family
Prasopora: This bryzoa of unknown species appears as nodular when found in its host rock. It is abundant in Ordivician rocks throughout central
Kentucky. This particular specimen is weathered and does not exhibit common Bryazoan features. In the linked immage it is the first of
three specimens.
C. Florida: This Bryzoan specimen is also very common in the Ordivician rocks of central Kentucky. It is possible to infer from this sample where
external aperatures existed and where the animal branched into its original, larger form. In the linked image the second and third
specimens are Constellarians.
Articulata
Orthida
Plectorthidae Dalmanellidae
Platystophiinae Resserellinae
Platystrophia: Reserella:
Specimens 1,2, and 3 The Reserella sample of unkonwn species also shows the straight hing line and costae ornamentation
respectively show the so common in the order Orthida. This order is known to inhabit rocks form the Cambrian to the
straight hinge line for Holocene. During the Ordovician, however, this order was at its height of abundance. It is no wonder
which this order is know, then that central Kentucky limestones are filled with these genera!
the brachial view, and the
pedicle view. Each view
also illistrates the radial
ornamentations known as
costae.
Cyrtosoma Cyrtosoma Diasoma
Gastropoda Cephalopoda Bivalvia
Crinozoa
Crinoids possess a stalk, calyx/cup, and arms which surve as feeding devices. In the linked image one can only see a single radial plate
from the stem of the crinoid. It is ,therefore, impossible to categorize the specimen further than its class. Crinoids are found in rocks from
the Cambrian to the modern day but saw their hayday in the Mississippian period. They resemble flowers when they are full grown and
becasue they generally establish their sessile existance near each other in the substrate people refer to them as "gardens of sea lilies".
Aluminum Ore
Aluminum Ore of non economic quality and unknown origin. May be a worthy indication that new exploration is needed in the area!
For more information about central Kentucky through time and particularly during the Ordovician (when my outcrop was deposited) please visit the Kentucky Geological Survey and the Kentucky Plaeontological Society web pages. They are easily accessed through any major browser under these call names. There you will be able to find much more information about geology in general and paleontology specifically. I hope that you enjoyed my page and I should give a special thanks to Sarah and Lee for helping me catch up on my project, Jimmy for keeping me smiling, and Dr. Chestnut for giving us such a relaxed classroom experience!
Contact me by email: rsgalv0@uky.edu
