Lake Carmel Pit (Lower Bay-Sound Clay) - Miller III (1983) (Holocene of the United States)

Also known as Lower Bay-Sound Clay, Lake Carmel Pit

Where: Orleans County, Louisiana (30.1° N, 90.0° W: paleocoordinates 30.1° N, 90.0° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Lower Member (Michoud Formation), Holocene (0.0 - 0.0 Ma)

• Five late Quaternary stratigraphic units are exposed at the Lake Carmel borrow pit. These in ascending order are : 1) deltaic equivalents of Deweyville terrace alluvium (Wisconsin); 2) a buried soil zone, "Little Woods paleosol" (late Wisconsin-early (Pleistocene); 3) bay-sound clay, "Michoud Formation" (middle Holocene); 4) barrier bar sand of the New Orleans trend (middle Holocene); 5) St Bernard prodeltaic and delta front deposits (late Holocene). This collection is from the Bay-Sound Clay (Michould Formation), a slightly shell, greenish gray, soft silty clay to clayey silt immediately above the Pleistocene unconformity. The botttom of the clay is dated at 7,290 and 7,200 years. The unit is 4 m thick. The collection comes from depth 9-10m

• bed-level stratigraphic resolution

Environment/lithology: paralic; poorly lithified, shelly/skeletal, gray, green, silty claystone and poorly lithified, shelly/skeletal, gray, green, argillaceous siltstone

• Radiocarbon dates mark the time when marshy paralic depositional environments reached the New Orleans East are at the advancing edge of the modern transgression of Gulf waters; adjacent paleofluves were probably flooded at this time and contained subtidal estuarine environments.
• Slightly shelly, greenish gray, soft silty clay to clayey silt.

Size class: macrofossils

Collection methods: bulk,

• All taxa collected and identified G. Mollyn. Unknown repository, though possibly Tulane University

Primary reference: W. Miller, III. 1983. Stratigraphy of newly exposed Quaternary seduments, eastern Orleans Parish, Louisiana. Tulane Studies in Geology and Paleontology 17(4):85-104 [A. Miller/A. Hendy/A. Hendy]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 41934: authorized by Austin Hendy, entered by Austin Hendy on 22.07.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• Exhaustive for mollusca. Key to abundance data: a=abundant; c=common; mc=moderately common; u=uncommon; r=rare.
Gastropoda
 Heterostropha - Pyramidellidae
Turbonilla interrupta Totten 1835 snail
 Opisthobranchia - Cylichnidae
Acteocina canaliculata Say 1826 barrel-bubble
 Sorbeoconcha - Littorinidae
"Littorina irrorata" = Littoraria irrorata
"Littorina irrorata" = Littoraria irrorata Say 1822 periwinkle
 Sorbeoconcha - Naticidae
Neverita duplicatus Say 1822 moon snail
 Neogastropoda - Columbellidae
"Anachis semiplicata" = Costoanachis semiplicata
"Anachis semiplicata" = Costoanachis semiplicata Stearns 1873 snail
 Neogastropoda - Nassariidae
Nassarius vibex Say 1822 snail
"Nassarius acutus" = Nassarius (Nassarius) acutus Say 1822 snail
Bivalvia
 Nuculanida - Nuculanidae
Nuculana concentrica Say 1824 Concentric Nut Clam
 Mytilida - Mytilidae
Geukensia demissa Dilwyn 1817 mussel
Subspecies: Geukensis demissa granosissima
Brachidontes exustus Linnaeus 1758 mussel
 Ostreida - Ostreidae
Crassostrea virginica Gmelin 1791 oyster
 Arcida - Arcidae
"Anadara ovalis" = Lunarca ovalis
"Anadara ovalis" = Lunarca ovalis Bruguiere 1789 ark
 Cardiida - Tellinidae
"Tellina texana" = Angulus texanus, Macoma tenta
"Tellina texana" = Angulus texanus Dall 1900 tellin clam
Macoma tenta Say 1834 tellin clam
 Cardiida - Veneridae
Mercenaria campechiensis Gmelin 1791 quahog
"Agriopoma texasiana" = Callocardia (Agriopoma) texasiana Dall 1892 venus clam
 Cardiida - Mactridae
Rangia cuneata Sowerby 1831 clam
 Pholadida - Corbulidae
"Corbula contracta" = Caryocorbula contracta
"Corbula contracta" = Caryocorbula contracta Say 1822 clam
 Pholadida - Pholadidae
Cyrtopleura costata Linnaeus 1758 clam