Near Eucla (Miocene of Australia)

Where: Western Australia, Australia (31.7° S, 128.9° E: paleocoordinates 41.1° S, 124.9° E)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Nullarbor Formation, Langhian (16.0 - 13.8 Ma)

• "Late early Miocene to early middle Miocene" according to O'Connell et al. (2012). Eucla Quarry and Eucla pass sections expose the lower/middle part of the Nullarbor (O'Connell et al., 2012), so an early middle Miocene age assigned here.

• group of beds-level stratigraphic resolution

Environment/lithology: open shallow subtidal; lithified limestone

• Facies are dominated byskeletal grainstones andfloatstones that accumulated in three interpreted paleoenvironments: (1) seagrass banks (upper photic zone), (2) rhodolith pavements (lower photic zone), and (3) open seafloors (lower photicto subphotic zone). The Southern Ocean extended inboard ~450 km from the shelf edge during Nullarbor Limestone deposition, but interpreted paleodepths did not extend much below the base of the photic zone. A small slope angle (~0.02°) over a wide shelf (~300,000 km2) implies deposition on an epeiric platform or epeiric ramp. A Miocene barrier reef was likely coeval with Nullarbor Limestone deposition. Therefore, the inboard portion of the Nullarbor Limestone can be considered part of an extensive back-reef lagoon system on a rimmed epeiric platform, perhaps attaining asize similar to the modern Great Barrier Reef system.

Size class: macrofossils

Collection methods: Repository: South Australian Museum

Primary reference: B. McGowran. 1959. Tertiary nautiloids (Eutrephoceras and Cimomia) from South Australia. Journal of Paleontology 33:435-448 [M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 171278: authorized by Matthew Clapham, entered by Matthew Clapham on 05.07.2015

Creative Commons license: CC BY (attribution)

Taxonomic list

Cephalopoda
 Nautilida - Nautilidae
"Eutrephoceras geelongensis" = Nautilus geelongensis
"Eutrephoceras geelongensis" = Nautilus geelongensis Foord 1891 nautiloid