Lower Conglomerate, Vaqueros Fm - Near Point, Santa Cruz Island (Oligocene of the United States)

Where: Santa Barbara County, California (34.0° N, 120.0° W: paleocoordinates 32.6° N, 111.8° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Lower Conglomerate Member (Vaqueros Formation), Chattian (28.1 - 23.0 Ma)

• The Vaqueros Formation is subdivided into two units on Santa Cruz Island, a lower conglomerate unit and an upper volcanic arenite. The collection is from the congomerate, which rests disconformably on the upper Eocene variegated shales of the Cozy Dell Formation, is 555 ft thick and comprised primarily of horneblende-diorite clasts.

• member-level stratigraphic resolution

Environment/lithology: coastal; lithified, medium-grained, coarse, shelly/skeletal, sandy, calcareous conglomerate

• High energy, shallow-water siliciclastic environment.
• Conglomerate, with fossiliferous, poorly sorted medium to coarse sandstone, and calcareous cement.

Size class: macrofossils

Collection methods: quarrying,

• Reported by Bereskin and Edward. Not sure of any repositories.

Primary reference: D. E. Weaver. 1969. Geology of the Northern Channel Islands. American Association of Petroleum Geologists - Pacific Section [A. Miller/A. Hendy/A. Hendy]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 52417: authorized by Austin Hendy, entered by Austin Hendy on 04.08.2005

Creative Commons license: CC BY (attribution)

Taxonomic list

• Nomenclature appears reasonable. Unsure of identifier.
 Sessilia - Balanidae
Balanus sp. Da Costa 1778 barnacle
 Sessilia - Tetraclitidae
Tetraclita sp. Schumacher 1817 barnacle
 Pectinida - Pectinoidae
Spondylus perrini Wiedey 1928 scallop
"Pecten vanvlecki" = Amussiopecten vanvlecki Arnold 1907 scallop
Lyropecten miguelensis Arnold 1906 scallop
 Ostreida - Flemingostreidae
"Ostrea miguelensis" = Acutostrea miguelensis
"Ostrea miguelensis" = Acutostrea miguelensis Hertlein 1928 oyster
 Mytilida - Mytilidae
"Mytilus expansus" = Crenomytilus expansus
"Mytilus expansus" = Crenomytilus expansus Arnold 1907 mussel
 Cardiida - Veneridae
Chione sp. von Mühlfield 1811 venus clam
Dosinia merriami Clark 1915 venus clam
Dosinia margaritana Wiedey 1928 venus clam
 Cardiida - Cardiidae
"Cardium (Trachycardium) vaquerosensis" = Trachycardium (Trachycardium) vaquerosensis
"Cardium (Trachycardium) vaquerosensis" = Trachycardium (Trachycardium) vaquerosensis Arnold 1908 cockle
 Neogastropoda - Muricidae
Trophon sp. Montfort 1810 murex snail
Rapana vaquerosensis Arnold 1908 murex snail
 Neogastropoda - Conidae
Conus sp. Linnaeus 1758 cone shell
 Naticoidea - Naticidae
"Polinices recluzianus" = Glossaulax reclusiana
"Polinices recluzianus" = Glossaulax reclusiana Deshayes 1839 moon snail
Subspecies: Polinices recluzianus andersoni
 Calyptraeoidea - Calyptraeidae
Calyptraea ? filosa Gabb 1866 slipper shell
 Sorbeoconcha - Turritellidae
Turritella ocoyana Conrad 1855 turret shell
 Dentaliida - Dentaliidae
Dentalium sp. Linnaeus 1758 tusk shell
 Clypeasteroida - Echinarachniidae