Benthic foraminiferal abundances from eight sites of the Northwest Australian shelf

DOI

Foraminiferal analysis of Miocene to recent strata of the Northwest Shelf of Australia is used to chart West Pacific Warm Pool (WPWP) influence. The assemblage is typified by "larger" foraminifera with ingressions of the Indo-Pacific "smaller" taxa Asterorotalia and Pseudorotalia at around 4 Ma and from 1.6 to 0.8 Ma. A review of recent and fossil biogeography of these taxa suggests their stratigraphic distribution can be used to document WPWP evolution. From 10 to 4.4 Ma a lack of biogeographic connectivity between the Pacific and Indian Ocean suggests Indonesian Throughflow (ITF) restriction. During this period, the collision of Australia and Asia trapped warmer waters in the Pacific, creating a central WPWP biogeographic province from the equator to 26°N. By 3 Ma Indo-Pacific species migrated to Japan with the initiation of the "modern" Kuroshio Current coinciding with the intensification of the North Pacific Gyre and Northern Hemisphere ice sheet expansion. Indo-Pacific taxa migrated to the northwest Australia from 4.4 to 4 Ma possibly because of limited ITF. The absence of Indo-Pacific taxa in northwest Australia indicates possible ITF restriction from 4 to 1.6 Ma. Full northwest Australian biogeographic connectivity with the WPWP from 1.6 to 0.8 Ma suggests an unrestricted stronger ITF (compared to today) and the initiation of the modern Leeuwin Current. The extinction of some Indo-Pacific species in northwest Australia after 0.8 Ma may be related to the effects of large glacial/interglacial oscillations and uplift of the Indonesian Archipelago causing Indonesian seaway restriction.

Supplement to: Gallagher, Stephen John; Wallace, Malcolm W; Li, Chung Leong; Kinna, Belinda; Bye, John A T; Akimoto, Kazumi; Torii, Masayuki (2009): Neogene history of the West Pacific Warm Pool, Kuroshio and Leeuwin currents. Paleoceanography, 24, PA1206

Identifier
DOI https://doi.org/10.1594/PANGAEA.758377
Related Identifier https://doi.org/10.1029/2008PA001660
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.758377
Provenance
Creator Gallagher, Stephen John ORCID logo; Wallace, Malcolm W ORCID logo; Li, Chung Leong; Kinna, Belinda; Bye, John A T; Akimoto, Kazumi; Torii, Masayuki
Publisher PANGAEA
Publication Year 2009
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 1254 data points
Discipline Earth System Research
Spatial Coverage (115.036W, -20.561S, 116.641E, -19.286N); North west Australian continental margin