Where: Northern Territory, Australia (17.1° S, 130.4° E: paleocoordinates 0.0° N, 0.0° E)

• coordinate stated in text

• outcrop-level geographic resolution

When: Blue Hole Formation (Limbunya Group), Statherian (1800.0 - 1600.0 Ma)

• The basal unit of the Limbunya Group is the unconformity-bound Stirling Sandstone, for which U-Pb sensitive high-resolution ion microprobe (SHRIMP) detrital zircon dating provides a maximum depositional age of 1830 ± 13 Ma (Carson 2013). A series of U–Pb zircon SHRIMP ages on tuffs in the middle Limbunya Group suggest that this interval was deposited c. 1655–1630 Ma (Fig. 1; Fanning 1991; Cutovinos et al. 2002; Dunster & Ahmad 2013), and similar c. 1640 Ma U–Pb zircon SHRIMP ages have been obtained from tuffs in the correlative McArthur Group in the McArthur Basin (e.g. Armstrong 1998; Smith 2001; Munson et al. 2020). Finally, a U-Pb zircon chemical abrasion-thermal ionization mass spectrometry (CA-ID-TIMS) age of 1642.2 ± 3.9 Ma has been obtained on a tuff in the Fraynes Formation, the penultimate formation of the Limbunya Group (Fig. 1; Munson et al. 2020). As such, geochronological data constrain Limbunya Group deposition to between c. 1800-1768 and 1635 Ma. Considering also the unconformity separating the Stirling Formation from the Limbunya Group, it is likely that most of the succession was deposited between c. 1655 and 1640 Ma.

• bed-level stratigraphic resolution

Environment/lithology: peritidal; lithified, dolomitic siltstone

Size class: microfossils

Preservation: original chitin

Collection methods: chemical, hydroflouric

• Repository: Museum and Art Gallery of the Northern Territory, Darwin (MAGNT)

Primary reference: L. A. Riedman, S. M. Porter, M. A. Lechte, A. Santos, and G. P. Halverson. 2023. Early eukaryotic microfossils of the late PalaeoproterozoicLimbunya Group, Birrindudu Basin, northern Australia. Papers in Palaeontology 9(e1538) [M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 232740: authorized by Matthew Clapham, entered by Matthew Clapham on 26.12.2023

Creative Commons license: CC BY (attribution)