Alum Bay, Middle Barton Beds, Isle of Wight (Eocene of the United Kingdom)

Also known as "London Clay" (Beds 4-6)

Where: England, United Kingdom (50.7° N, 1.6° W: paleocoordinates 49.1° N, 5.5° W)

• coordinate based on nearby landmark

• local area-level geographic resolution

When: Middle Member (Barton Beds Formation), Late/Upper Eocene (37.2 - 33.9 Ma)

• beds 4-6 (numbered from bottom to top). Prestwich's stratigraphy is a bit screwy. No one else has recognized the London Clay in this area. This bed is probably part of the Barton Beds (Bosma, 1974). Gardner et al. are the first I've found who call these Barton Beds.

• group of beds-level stratigraphic resolution

Environment/lithology: marine; sandy claystone and pebbly, brown, gray, green, red, sandy, calcareous, carbonaceous claystone

• Dark brown sandy clay with two layers of septaria. A few remains of shells and traces of plants occur in this bed, together with a seam of small flint pebbles. Top of the bed darkest and most fossiliferous. This bed underlain by sand with clay seam which is underlain by dark brown clay, with several layers of septaria, and one thin band of calcareous greenish grey sandstone. The lower part slightly red. At the bottom a thickness of one to two feet is mixed with sand, and contains large rounded flint pebbles. another layer of small flint pebbles occurs near the centre. Organic remains, which are scarce in the lower part, are numerous higher up, especially in the bed containing the small pebbles. Among the large pebbles at the bottom, sharks' teeth are found.

Size classes: macrofossils, mesofossils

Collection methods: Prestwich claims that Bowerbank's Cancer Leachii goes with this bed, but it doesn't seem to fit with the strat columns in both papers. Bowerbank puts this bed at the top of the London Clay, while Prestwich puts it at the bottom.

Primary reference: J. S. Bowerbank. 1839. On the London and Plastic Clay Formations of the Isle of Wight. Transactions of the Geological Society of London, series 2 6:169-172 [J. Alroy/E. Leckey/P. Wagner]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 39696: authorized by John Alroy, entered by Erin Leckey on 03.06.2004, edited by Austin Hendy

Creative Commons license: CC BY (attribution)

Taxonomic list

 Decapoda - Zanthopsidae
"Cancer leachii" = Zanthopsis leachii
"Cancer leachii" = Zanthopsis leachii Desmarest 1822 crab
 Arcida - Glycymerididae
"Pectunculus brevirostris" = Glycymeris brevirostris1
"Pectunculus brevirostris" = Glycymeris brevirostris1 Sowerby 1824 clam
 Ostreida - Ostreidae
Ostrea sp. Linnaeus 1758 oyster
two species
 Ostreida - Pinnidae
"Pinna affinis" = Atrina affinis1
"Pinna affinis" = Atrina affinis1 Sowerby 1821 oyster
 Carditida - Carditidae
"Venericardia planicostata" = Venericor planicosta
"Venericardia planicostata" = Venericor planicosta Lamarck 1801 clam
var. ?Suessonensis
 Pholadida - Corbulidae
Corbula sp.1 Bruguière 1789 clam
 Cardiida - Mactridae
Lutraria sp.1 Lamarck 1799 clam
 Cardiida - Veneridae
Venus sp. Linnaeus 1758 venus clam
 Cardiida - Cardiidae
 Hiatellida - Hiatellidae
"Panopaea virgula" = Panopea1, "Panopaea intermedia" = Panopea intermedia1
"Panopaea virgula" = Panopea1 clam
"Panopaea intermedia" = Panopea intermedia1 Sowerby 1814 clam
 Pholadomyida - Pholadomyidae
"Pholadomya margaritacea" = Pholadomya (Bucardiomya) margaritacea1
"Pholadomya margaritacea" = Pholadomya (Bucardiomya) margaritacea1 Sowerby 1821 clam
 Nuculida - Nuculidae
"Nucula similis" = Nucula (Pronucula) similis Cossmann and Pissarro 1904 nut clam
 Neogastropoda - Buccinidae
 Neogastropoda - Melongenidae
"Pyrula sp." = Melongena (Pyrula)1
"Pyrula sp." = Melongena (Pyrula)1 Lamarck 1799 snail
 Neogastropoda - Muricidae
Murex innexus murex snail
 Neogastropoda - Turridae
"Pleurotoma sp." = Turris1
"Pleurotoma sp." = Turris1 Röding 1798 turrid
 Stromboidea - Strombidae
"Rostellaria sowerbyi" = Tibia1, "Fusus sp." = Rostellaria (Fusus)1
"Rostellaria sowerbyi" = Tibia1 true conch
"Fusus sp." = Rostellaria (Fusus)1 Bruguière 1789 true conch
 Naticoidea - Naticidae
Natica sp.1 Scopoli 1777 moon snail
 Vermetoidea - Vermetidae
 Calyptraeoidea - Calyptraeidae
Calyptraea (Trochita) aperta2 Solander 1766 slipper shell
 Sorbeoconcha - Turritellidae
Turritella edita, "Turritella elongata" = Haustator elongatus, "Turritella conoidea" = Haustator conoidea, "Turritella imbricataria" = Haustator imbricataria1
Turritella edita turret shell
"Turritella elongata" = Haustator elongatus Sowerby 1814 turret shell
"Turritella conoidea" = Haustator conoidea Sowerby 1814 turret shell
"Turritella imbricataria" = Haustator imbricataria1 Lamarck 1804 turret shell
 Sorbeoconcha - Cerithiidae
Cerithium sp.1 Bruguière 1789 cerith snail
 Dentaliida - Dentaliidae
Dentalium planum1 tusk shell
 Selachii -
Plantae indet.1 Haeckel 1866