Where: Northern Territory, Australia (16.7° S, 135.7° E: paleocoordinates 0.0° N, 0.0° E)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Balbirini Dolomite Formation (Nathan Group), Calymmian (1600.0 - 1400.0 Ma)

• The Balbirini Dolomite is constrained by U-Pb (SHRIMP) ages of 1609 +/- 3 Ma and 1613 +/- 4 Ma near its base in the Evaporitic Unit, and 1589 +/- 3 Ma near the top (Page et al., 2000). The Balbirini is divided into two unconformity-bound packages, with the microfossil-bearing Stromatolitic Unit assigned to the upper package by Jackson & Southgate (2000). Given the unconformity, it is likely that the microfossil-bearing part of the Balbirini Dolomite formed closer to 1590 Ma, in the Mesoproterozoic (Calymmian) rather than prior to 1600 Ma.

• bed-level stratigraphic resolution

Environment/lithology: peritidal; lithified, stromatolitic, cherty/siliceous dolomite

Size class: microfossils

Preservation: permineralized, original carbon, replaced with silica

Collected by M.D. Muir, K.A. Plumb in 1972

Collection methods: peel or thin section

• Repository: Commonwealth Palaeontology Collection, Canberra

Primary reference: D. Z. Oehler. 1978. Microflora of the middle Proterozoic Balbirini Dolomite (McArthur Group) of Australia. Alcheringa 2:269-309 [M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 227560: authorized by Matthew Clapham, entered by Matthew Clapham on 15.10.2022

Creative Commons license: CC BY (attribution)