Table 2.
Chronometric ages for South Walker Creek sites and their reliability score.
| QML1470 | Dating method | Association | Score | n | Age interpretation | Age (ka) | |
|---|---|---|---|---|---|---|---|
| SW9 | US-ESR (SCU) | Direct (m*) | Yes—w | A* | 5 | Age of megafauna fossils within Unit C. | 32.5 ± 2.5 (2σ)a |
| US (UQ) | Direct (m) | Yes—w | A | 4 | Minimum age of megafauna fossils within Unit C. | 24.5 ± 0.1 (2σ)b | |
| US (UOW) | Direct (m) | Yes—w | A | 2 | Minimum age of megafauna fossils within Unit C. | 25.5 ± 0.1 (2σ)b | |
| OSL (AU + GU) | Indirect (m) | Yes—a, w + b | A | 19 | Age of Unit C, including fossiliferous layer. | 41.3 ± 1.9 (1σ)a | |
| OSL + US-ESR (ALL) | Both | Yes—a, w + b | A* + A | 24 | Combined age of megafauna and deposit. | 40.1 ± 1.7 (1σ)a | |
| C14 (charcoal) (ANU) | Indirect (B) | Yes—w + b | B | 3 | Minimum maximum age of deposit. | > 40–50 kac | |
| SW3 | OSL (AU) | Indirect (m) | Yes—w + b | A | 5 | Age of entire deposit including fossiliferous layer. | 47.7 ± 3.2 (1σ)a |
| SWCC | OSL (AU) | Indirect (m) | Yes—a + w | A | 2 | Age of entire deposit (Units B, C & D), including fossiliferous layers. | 58.2 ± 6.1 (1σ)a |
| SWJ | OSL (AU) | Indirect (m) | Yes—b | A | 6 | Age of Unit B, maximum age of fossiliferous Unit C. | 65.62.2 (1σ)a |
Ratings of dating methods uses established criteria11. All chronometric results, including detailed methods, are provided in the Methods and Supplementary Notes 5–8. m, m*, B, A and A* are categories and ratings defined here11.
a above, b below, w within the fossiliferous layer.
aWeighted mean age and uncertainty.
bOldest age and uncertainty.
cReworked macro-charcoal represents a maximum age for the deposit, however, this material only survived ABA treatment, therefore must be considered a minimum age range. Radiocarbon dates on sediment are not included here as the data is not acceptable according to Rodrigues-Rey11.