Research Article

Evolutionary Biology

The age of Homo naledi and associated sediments in the Rising Star Cave, South Africa

James Cook University, Australia
University of the Witwatersrand, South Africa
University of Johannesburg, South Africa
University of Wisconsin-Madison, United States
University of Wollongong, Australia
Environmental Futures Research Institute, Griffith University, Australia
Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), Spain
The Australian National University, Australia
The University of Melbourne, Australia
La Trobe University, Australia
Southern Cross University, Australia

May 9, 2017

https://doi.org/10.7554/eLife.24231

Open access
Copyright information

Figures
Tables

14 figures and 10 tables

Figures

Figure 1

Download asset Open asset

Location of Rising Star Cave and the Dinaledi Chamber.

(a) Simplified geological map showing the position of the Rising Star Cave (in grey); (b) close-up map of the Dinaledi Chamber showing the distribution of the dating samples, including: U-Th flowstone samples (yellow dots, black text); ESR samples (purple dots, orange text); and OSL samples (red dots, blue text). Age estimates for the different samples are shown, with cross reference to Tables 1, 7 and 8.

https://doi.org/10.7554/eLife.24231.003

Figure 2

Download asset Open asset

Geological face map and cross-sections through the sediment pile at different locations in the Dinaledi Chamber, illustrating the relationships between the flowstone groups and sedimentary units.

The positions of the section lines are shown in (a); a face map of the entry zone of the Dinaledi Chamber (looking NE) is shown in (b); geological cross-sections through the central part of the Dinaledi Chamber near the excavation pit are shown in (c) and (d).

https://doi.org/10.7554/eLife.24231.004

Figure 3

Download asset Open asset

Field and close-up photographs of all flowstone samples collected for U-Th dating.

The flowstone groups (i.e., Flowstone Groups 1, 2 or 3), sample numbers, and ages (2σ uncertainty), as listed in Table 1, are shown below each sample. Ages reported here are from JCU, unless otherwise stated.

https://doi.org/10.7554/eLife.24231.005

Figure 4

Download asset Open asset

Location of the three *H. naledi* tooth samples (samples 1767, 1788 and 1810) and one baboon (cf. *Papio*) tooth sample (sample 1841) used for combined U-series and ESR dating.

(a) Map of the Dinaledi Chamber showing the position of the excavation pit and the position of figures (b) and (c); (b) close-up of the SE corner of the excavation pit showing the sample site for sample 1810 and the 50 cm deep sondage from which sample 1841 was recovered; (c) the area to the W of the excavation pit from which samples 1767 and 1788 were collected.

https://doi.org/10.7554/eLife.24231.011

Figure 5

Download asset Open asset

Samples of orange laminated mudstone of Unit 1 for OSL dating.

(a) sample OSL3 with an estimated MAM age of 231 ± 41 ka taken from sub-unit 1b; (b) sample OSL4 with an estimated MAM age of 241 ± 37 ka, taken from sub-unit 1b and covered by a flowstone sheet dated at 290 ± 6 ka (RS5); (c) sample OSL5 with an estimated MAM age of 353 ± 61 ka, taken from sub-unit 1a and covered by a flowstone sheet dated at 32.1 ± 0.4 ka (RS20). The scale bar in each of the photographs is 10 cm.

https://doi.org/10.7554/eLife.24231.012

Figure 6

Download asset Open asset

Photographs of *H. naledi* teeth used for ESR dating.

(a) U.W.101–1767; (b) U.W.101–1788; (c) U.W.101–1810. The order of images for each panel is: buccal, distal, lingual, mesial, and occlusal views. The scale bar in each panel is 1 cm.

https://doi.org/10.7554/eLife.24231.013

Figure 7

Download asset Open asset

Photographs of the baboon (cf. *Papio*) tooth (sample 1841), recovered from the sondage in the excavation pit, and used for ESR dating.

Views are: (a) buccal, (b) occlusal, (c) lingual, and (d) internal.

https://doi.org/10.7554/eLife.24231.014

Figure 8

Download asset Open asset

Cartoon illustrating the sedimentary history resulting in the deposition and redistribution of sediment of Units 2 and 3, and Flowstone Groups 1 to 3 in the Dinaledi Chamber.

Note that all hominin fossils are contained in sub-unit 3b, but that this sub-unit has been repeatedly reworked after its initial deposition. Fossil entry occurred during the initial stages of deposition of Unit 3 below the entry shaft and predated deposition of Flowstone 1c. *H. naledi* fossils may have continued to enter the Dinaledi Chamber as older parts of Unit 3 were eroded from below Flowstone 1c, and as remnants of all older units were reworked to be incorporated into Unit 3 sediments that accumulated along the floor of the Dinaledi Chamber.

https://doi.org/10.7554/eLife.24231.019

Figure 9

Download asset Open asset

Photographs illustrating the sampling approaches taken by SCU-UoW and GU-ANU in obtaining the U-Th results presented in Tables 4 and 5.

(a) Comparison of sampling grids across the enamel-dentine boundary measured by SCU-UoW (red lines) vs. GU-ANU (blue circles). SCU-UoW (red lines) measured a series of parallel, shallow (<5 μm) pits along grid lines across the teeth and averaged U concentrations across each grid. GU-ANU (blue circles) measured the average composition of the tooth in single spots that were laser-bored along profiles across the teeth, and report results for each spot. (**b, c**) Locations of LA-ICP-MS spot analyses for teeth samples 1788 (b) and 1810 (c) conducted by GU-ANU. The detailed transects are shown in panels (d) to (h).

https://doi.org/10.7554/eLife.24231.020

Figure 10

Download asset Open asset

Gamma dose rate reconstructions derived from analytical data of sediment samples collected around ESR samples 1767, 1788 and 1810 (closed circles and diamonds), combined with samples from a vertical profile in the excavation pit and sondage (open circles and diamonds).

The data show little variation in dose rate with depth (see text for explanation).

https://doi.org/10.7554/eLife.24231.021

Figure 11

Download asset Open asset

ESR dose response curves (DRC’s) obtained for the samples 1767, 1788, 1810 and 1841.

To facilitate comparison, all DRC’s have been normalised to the intensity of the natural point (=1).

https://doi.org/10.7554/eLife.24231.023

Figure 12

Download asset Open asset

Evolution of the I_max/I_min ratio vs the irradiation dose for the four tooth samples.

(see text for explanation).

https://doi.org/10.7554/eLife.24231.024

Figure 13

Download asset Open asset

Samples and results of palaeomagnetic analyses forFlowstone 1a.

(a) Outcrop photo of hanging erosion remnant of Flowstone 1a from which the palaeomagnetic sample was taken. The three flowstone phases separated by detrital horizons are clearly visible, and their magnetic polarity has been marked (N = normal; R = reverse). The stratigraphic top is towards the top of the photo; (b) close-up of a hand sample taken for palaeomagnetic analysis from Flowstone 1a in the Dinaledi Chamber. The sample is layered and comprises three distinct phases (from base to top: A-C marked in yellow) separated by thin clastic horizons that mark disconformities indicated with red dashed lines. The larger-scale extent of the three phases can be seen in (a); (c) intensity spectra, Zijderveld plots, and stereo plots for samples from phases A to C taken from (b). Phases B and C show normal polarity and phase A shows reversed and intermediate polarity directions.

https://doi.org/10.7554/eLife.24231.025

Figure 14

Download asset Open asset

Chronostratigraphic summary of radio-isotopic dating results, and interpretation of the depositional ranges of stratigraphic units, flowstones and H.

*naledi* fossils in the Dinaledi Chamber. Following the preferred US-ESR maximum age model and associated uncertainties for ESR samples 1788 and 1810, a maximum depositional age of 335 Ma was determined, while the minimum depositional age of 236 ka was constrained by Flowstone 1c (sample RS18), which covers *H. naledi* material in the entry zone.

https://doi.org/10.7554/eLife.24231.026

Tables

Table 1

Summary table of U-Th disequilibrium ages obtained for samples from the Dinaledi Chamber by James Cook University (JCU - ¹) and the University of Melbourne (UoM - ²). The detailed analytical results are shown in Tables 2 and 3. Sample locations are shown in Figure 1b. The data are ranked by increasing age of the oldest flowstone horizon within the sample, based on the JCU ages. The grey shading highlights the different age groupings observed within the flowstones: 24–32 ka, ~50 ka, 88–105 ka, ~242 ka, ~290 ka and >440 ka. Ages are reported relative to 1950.

https://doi.org/10.7554/eLife.24231.006

Sample ID	Flowstone group	Underlying unit	Age¹ (ka)	2σ¹ (ka)	Age² (ka)	2σ² (ka)
RS19	FS2	sub-unit 3b	24.7	0.2	24.53	0.43
RS11	FS3 (top to RS21)	FS2	9.05	0.06	9.946	0.063
RS21	FS2 (base to RS11)	sub-unit 3b	28.4	0.4	28.62	0.29
RS10	FS2	sub-unit 3b (and bone)	30.1	0.3	–	–
RS20	FS2	sub-unit 1a (Facies 1a; OSL5)	30.4	0.2	32.12	0.38
RS6	FS2	sub-unit 1a, sub-unit 3b	49.8	0.3	50.82	0.43
RS15	FS2 (blind duplicate of RS1)	sub-unit 3b	92.6	1.0	91.40	0.65
RS1	FS2 (blind duplicate of RS15)	sub-unit 3b	–	–	91.04	0.72
RS8	FS2 (below FS1a-e)	sub-unit 3b	95.0	1.0	96.29	0.69
RS14	FS2	in drain, along dolostone wall	100.1	1.2	96.20	0.36
RS17	FS2 (top to RS16)	in drain, along dolostone wall	102.6	0.8	98.6	1.4
RS16	FS2 (base to RS17)	in drain, along dolostone wall	104.0	1.9	99.1	1.4
RS13	FS2 (rim to RS18)	sub-unit 3b	–	–	88.46	0.67
RS18	FS1c (core to RS13)	sub-unit 3b	242	5	242.9	6.6
RS5	FS1	sub-unit 1b (Facies 1b; OSL4)	290	6	–	–
RS22	FS1a (top to RS23)	Unit 2	equilibrium	–	478	+107/−41
RS23	FS1a (base to RS22)	Unit 2	equilibrium	–	502	+181/−53
RS9	n/a (surface outcrop)	n/a	equilibrium	–	equilibrium	–

¹James Cook University (JCU), Advanced Analytical Centre.
²University of Melbourne (UoM), paleochronology laboratory.

Table 2

U-Th data table for James Cook University. Uncertainties include: analytical error, decay constant uncertainty, and uncertainty on initial ²³⁰Th/²³²Th. Ages are reported relative to 1950 and assume an initial ²³⁰Th/²³²Th activity of 0.83 ± 0.5, and the equation given in Placzek et al. (2006). Decay constants for ²³⁴U and ²³⁰Th are from Cheng et al. (2013).

https://doi.org/10.7554/eLife.24231.007

Sample ID	U (ppm)	²³⁴U/²³⁸U	2σ	²³⁰Th/²³⁸U	2σ	²³²Th/²³⁸U	2σ	Age (ka BP)	2σ (ka)	²³⁴U/²³⁸U_initial	2σ
		(activity)		(activity)				(corrected)		(activity)
RS11	2.314	1.772	0.050	0.144	0.001	0.0001088	0.0000005	9.05	0.06	1.8184	0.0003
RS19	0.652	1.855	0.001	0.387	0.002	0.002176	0.000008	24.7	0.2	1.989	0.001
RS21	0.421	1.946	0.001	0.460	0.004	0.001920	0.000015	28.4	0.4	2.109	0.002
RS10	0.846	1.885	0.001	0.466	0.003	0.000792	0.000003	30.1	0.3	2.053	0.001
RS20	0.795	1.855	0.001	0.463	0.003	0.001363	0.000005	30.4	0.2	2.022	0.001
RS6	0.560	1.966	0.001	0.747	0.003	0.000974	0.000002	49.8	0.3	2.263	0.002
RS15	0.400	1.912	0.001	1.164	0.008	0.00472	0.00001	92.6	1.0	2.484	0.007
RS8	0.328	1.813	0.003	1.120	0.008	0.00316	0.00002	95.0	1.0	2.373	0.007
RS14	0.734	1.639	0.095	1.039	0.008	0.00298	0.00002	100.1	1.2	2.175	0.008
RS17	0.680	1.609	0.001	1.032	0.005	0.000679	0.000001	102.6	0.8	2.150	0.005
RS16	0.973	1.583	0.000	1.024	0.011	0.000403	0.000006	104.0	1.9	2.12	0.01
RS18	0.152	1.848	0.001	1.856	0.013	0.01175	0.00005	242	5	3.66	0.05
RS5	0.090	1.728	0.001	1.818	0.009	0.01732	0.00005	290	6	3.92	0.07
RS23	0.314	1.187	0.002	1.315	0.011	0.00346	0.00002	>400	–	–
RS22	0.367	1.209	0.001	1.322	0.008	0.000125	0.000001	>400	–	–
RS9	0.737	1.007	0.002	1.029	0.004	0.000462	0.000001	>400	–	–

Table 3

U-Th data table for the University of Melbourne. Activity ratios are determined after Hellstrom (2003) and Drysdale et al. (2012). Ages are corrected for initial ²³⁰Th using Equation 1 of Hellstrom (2006), the decay constants of Cheng et al. (2013), and an initial ²³⁰Th/²³²Th activity of 1.5 ± 1.5. The initial ²³⁴U/²³⁸U ratios are calculated using corrected ages, which are reported relative to 1950.

https://doi.org/10.7554/eLife.24231.008

Sample ID	U (ppm)	²³⁴U/²³⁸U	2σ	²³⁰Th/²³⁸U	2σ	²³²Th/²³⁸U	2σ	Age (ka BP)	2σ (ka)	²³⁴U/²³⁸U_initial	2σ
		(activity)		(activity)				(corrected)		(activity)
RS11	1.518	1.808	0.003	0.1597	0.0009	0.0000875	0.0000004	9.946	0.063	1.831	0.004
RS19	0.501	1.884	0.011	0.3916	0.0026	0.004322	0.000010	24.53	0.43	1.947	0.011
RS21	0.361	1.968	0.011	0.4654	0.0030	0.0011342	0.0000019	28.62	0.29	2.049	0.011
RS20	0.626	1.878	0.011	0.4925	0.0032	0.0023837	0.0000040	32.12	0.38	1.961	0.011
RS6	0.276	2.023	0.004	0.7856	0.0021	0.00496	0.00010	50.82	0.43	2.181	0.004
RS13	0.076	2.006	0.004	1.1837	0.0047	0.004786	0.000058	88.46	0.67	2.291	0.005
RS15	0.381	1.934	0.004	1.1661	0.0029	0.00639	0.00012	91.37	0.65	2.209	0.005
RS14	0.665	1.626	0.003	1.0010	0.0015	0.001262	0.000014	96.24	0.36	1.822	0.003
RS8	0.257	1.831	0.004	1.1397	0.0034	0.005746	0.000060	96.29	0.69	2.091	0.004
RS17	0.517	1.637	0.009	1.0248	0.0066	0.0023963	0.0000037	98.6	1.4	1.841	0.010
RS16	0.905	1.590	0.010	0.9963	0.0067	0.0017099	0.0000037	99.1	1.4	1.780	0.011
RS18	0.104	2.001	0.011	2.0320	0.0140	0.020557	0.000041	242.9	6.6	2.987	0.027
RS22	0.324	1.228	0.007	1.3017	0.0083	0.0001201	0.0000008	478	+107/–41	–	–
RS23	0.206	1.225	0.007	1.3016	0.0093	0.007818	0.000016	502	+181/–53	–	–
RS9	0.896	1.010	0.002	1.0204	0.0018	0.000916	0.000012	–	–	–	–

Table 4

Summary table of U-Th disequilibrium ages obtained for the three H. naledi teeth (samples 1767, 1788 and 1810) and the baboon tooth (sample 1841) from the Dinaledi Chamber obtained by SCU-UoW. No age calculations were carried out for U concentrations of ≤0.5 ppm or U/Th ≤250 (indicated in red and underlined). Mean values in this table only incorporate values from which meaningful ages could be calculated (indicated in black), however all values (i.e., red and black) were averaged to obtain the relevant mean values reported in Table 4. All uncertainties are given as 2σ.

https://doi.org/10.7554/eLife.24231.009

Sample1767	U (ppm)	U/Th	²³⁰Th/²³⁸U	2σ	²³⁴U/²³⁸U	2σ	Age (ka)	2s (ka)	⁽²³⁴U/²³⁸U)i	2σ
1767-1 D	7.22	685	2.167	0.024	6.259	0.009	43.5	1.1	6.949	0.026
1767-2 D	7.75	996	2.261	0.023	6.282	0.010	45.5	1.1	7.009	0.030
1767-3 D	8.03	196	2.225	0.825	6.276	0.012	–	–	–	–
1767-4 D	8.55	951	2.209	0.031	6.301	0.009	44.1	1.4	7.007	0.030
1767-5* E	3.69	1238	2.259	0.031	6.197	0.055	46.2	1.8	6.924	0.126
1767-6* E	1.76	108	2.239	1.133	6.165	0.038	–	–	–	–
1767-7* E	2.15	109	2.337	0.947	6.231	0.024	–	–	–	–
1767-8* E	2.46	518	2.276	0.021	6.253	0.019	46.1	1.1	6.986	0.048
Mean:
1767 D	7.84	877	2.212	0.026	6.281	0.009	44.5	1.2	6.988	0.029
1767 E	3.08	878	2.268	0.026	6.225	0.037	46.2	1.4	6.955	0.087
Sample1788	U (ppm)	U/Th	²³⁰Th/²³⁸U	2σ	²³⁴U/²³⁸U	2σ	Age (ka)	2s (ka)	⁽²³⁴U/²³⁸U)i	2σ
1788-1 D	6.67	390	2.967	0.026	6.423	0.011	61.4	1.5	7.453	0.054
1788-2 D	7.08	176	3.370	0.833	6.441	0.010	–	–	–	–
1788-3 D	7.17	60	3.206	3.126	6.394	0.049	–	–	–	–
1788-4 D	7.45	1391	3.313	0.023	6.445	0.010	70.3	1.4	7.645	0.056
1788-5 D	5.52	4423	3.269	0.023	6.349	0.010	70.4	1.4	7.531	0.052
1788-6 D	5.07	4090	3.416	0.014	6.378	0.014	74.1	1.1	7.634	0.054
1788-7 D	5.39	4729	3.385	0.020	6.400	0.014	72.9	1.4	7.640	0.054
1788-8 D	5.93	3209	3.427	0.015	6.393	0.013	74.2	1.1	7.654	0.054
1788-9 D	5.24	4329	3.449	0.014	6.413	0.014	74.5	1.0	7.685	0.052
1788-10 D	4.89	3161	3.390	0.010	6.403	0.011	73.0	0.9	7.645	0.052
1788-11 D	4.8	2556	3.394	0.014	6.416	0.014	72.9	1.0	7.659	0.052
1788-12 D	5.48	1606	3.356	0.017	6.384	0.014	72.3	1.1	7.609	0.052
1788-13 D	5.04	838	3.317	0.025	6.420	0.014	70.7	1.5	7.623	0.058
1788-14 D	5.69	93	3.281	2.426	6.408	0.013	–	–	–	–
1788-15 D	5.03	72	3.315	3.731	6.427	0.014	–	–	–	–
1788-16 E	0.13	3	1.786	18.149	3.834	0.267	–	–	–	–
1788-17 E	0.68	25	0.752	9.149	6.248	0.273	–	–	–	–
1788-18 E	0.4	16	0.801	13.053	6.236	0.050	–	–	–	–
1788-19 E	0.08	3	1.783	36.231	4.301	0.288	–	–	–	–
1788-20 E	1.02	306	2.990	0.117	5.541	0.154	75.1	9.3	6.617	0.394
1788-21* E	0.33	50	2.041	27.135	5.793	0.141	–	–	–	–
1788-22* E	0.12	30	1.513	24.801	5.975	0.098	–	–	–	–
1788-23* E	0.25	34	1.368	17.071	5.988	0.079	–	–	–	–
1788-24* E	0.36	90	1.237	13.555	6.167	0.055	–	–	–	–
1788-25* E	0.41	107	1.084	8.672	6.206	0.033	–	–	–	–
1788-26* E	0.48	102	1.302	11.333	6.384	0.081	–	–	–	–
1788-27* E	0.49	165	0.686	7.733	6.367	0.037	–	–	–	–
1788-28* E	0.31	167	1.615	6.975	5.602	0.246	–	–	–	–
1788-29* E	0.44	6	2.311	11.898	5.576	0.306	–	–	–	–
1788-30 E	0.44	62	0.988	5.310	6.089	0.075	–	–	–	–
1788-31 E	0.29	8	1.066	19.256	6.151	0.056	–	–	–	–
1788-32 E	0.23	95	0.994	17.451	6.352	0.064	–	–	–	–
1788-33 E	0.41	6	1.103	21.651	6.344	0.049	–	–	–	–
1788-34 E	0.28	51	1.340	11.450	6.382	0.061	–	–	–	–
1788-35 E	0.35	4	1.286	21.088	6.321	0.062	–	–	–	–
1788-36 E	0.4	115	1.216	12.896	6.372	0.041	–	–	–	–
1788-37 E	0.3	61	1.106	17.059	6.313	0.073	–	–	–	–
1788-38 E	0.54	279	2.810	0.237	6.300	0.064	58.9	12.2	7.262	0.270
Mean:
1788 D	5.59	2793	3.335	0.018	6.402	0.013	71.5	1.2	7.616	0.054
1788 E	0.78	293	2.900	0.177	5.920	0.109	67.0	10.8	6.936	0.332
Sample1810	U (ppm)	U/Th	²³⁰Th/²³⁸U	2σ	²³⁴U/²³⁸U	2σ	Age (ka)	2s (ka)	⁽²³⁴U/²³⁸U)i	2σ
1810-1 D	7.07	348	3.231	0.021	5.814	0.017	77.9	1.6	7.003	0.056
1810-2 D	8.29	411	3.112	0.030	5.863	0.010	73.4	2.1	6.986	0.062
1810-3 D	8.88	979	3.106	0.027	5.929	0.010	72.1	1.8	7.046	0.060
1810-4 D	9.19	833	3.049	0.044	5.993	0.011	69.4	2.6	7.079	0.066
1810-5 D	9.17	508	2.937	0.047	5.990	0.007	66.2	2.8	7.020	0.066
1810-6 D	9.12	55	3.143	6.919	5.981	0.012	–	–	–	–
1810-7 D	7.95	432	3.099	0.018	5.977	0.013	71.1	1.3	7.089	0.054
1810-8 D	8.84	489	2.986	0.074	6.035	0.060	67	4.1	7.088	0.084
1810-9 D	9.39	15905	3.122	0.013	5.870	0.006	73.6	1.1	6.999	0.052
1810-10 D	9.78	7839	3.165	0.017	5.873	0.011	74.8	1.3	7.024	0.054
1810-11 D	9.03	7242	3.174	0.030	5.888	0.015	74.8	2.0	7.043	0.058
1810-12 D	9.53	9626	3.157	0.019	5.889	0.009	74.3	1.4	7.036	0.054
1810-13 D	10.19	10240	3.094	0.018	5.904	0.008	72.2	1.3	7.016	0.052
1810-14 D	10.64	14463	3.155	0.030	5.958	0.010	73.1	1.9	7.099	0.058
1810-15 E	0.005	1	−0.384	146.036	1.965	0.186	–	–	–	–
1810-16 E	0.002	2	−1.060	48.168	1.014	0.108	–	–	–	–
1810-17 E	0.004	1	5.403	17.573	2.357	0.194	–	–	–	–
1810-18 E	0.24	55	3.195	9.109	4.054	0.062	–	–	–	–
1810-19 E	0.54	426	4.009	0.186	5.054	0.109	130.8	21.8	6.872	0.466
1810-20 E	0.85	328	3.625	0.119	4.287	0.137	146.8	22.7	5.984	0.524
1810-21 E	0.41	48	5.009	4.474	4.494	0.186	–	–	–	–
1810-22 E	0.15	7	7.690	8.225	4.349	0.351	–	–	–	–
1810-23 E	0.03	2	9.912	1.843	5.153	0.599	–	–	–	–
1810-24 E	0.01	0	0.661	166.056	1.877	0.144	–	–	–	–
1810-25 E	0.02	2	7.408	9.386	4.964	0.557	–	–	–	–
1810-26* E	0.73	3	3.762	4.100	4.735	0.100	–	–	–	–
1810-27* E	0.14	3	5.271	4.510	4.255	0.112	–	–	–	–
1810-28* E	0.18	5	3.541	8.079	4.562	0.081	–	–	–	–
1810-29* E	0.25	9	3.511	7.095	4.562	0.058	–	–	–	–
1810-30* E	0.21	3	4.027	5.291	4.073	0.149	–	–	–	–
1810-31* E	0.09	1	3.875	39.136	4.029	0.072	–	–	–	–
1810-32* E	0.05	2	2.469	9.099	4.187	0.072	–	–	–	–
1810-33* E	0.06	1	2.602	24.169	4.426	0.141	–	–	–	–
1810-34* E	0.91	2010	3.131	0.068	4.561	0.032	105.2	7.0	5.798	0.128
1810-35 E	1.01	3	4.291	15.514	4.085	0.025	–	–	–	–
1810-36 E	0.04	99	6.297	8.890	4.060	0.242	–	–	–	–
1810-37 E	0.14	528	5.753	3.932	4.385	0.234	–	–	–	–
1810-38 E	0.02	55	5.687	28.490	4.211	0.437	–	–	–	–
1810-39 E	0.01	17	4.203	31.048	4.474	0.314	–	–	–	–
1810-40 E	2.09	1586	3.993	0.049	4.993	0.037	132.5	6.2	6.814	0.146
Mean:
1810 D	9.07	5332	3.107	0.030	5.922	0.0145	72.3	1.9	7.040	0.060
1810 E	1.10	1088	3.690	0.105	4.724	0.0788	128.8	14.4	6.595	0.316
Sample1841	U (ppm)	U/Th	²³⁰Th/²³⁸U	2σ	²³⁴U/²³⁸U	2σ	Age (ka)	2s (ka)	⁽²³⁴U/²³⁸U)i	2σ
1841-1 E	2.51	78	4.415	3.252	5.851	0.035	–	–	–	–
1841-2 E	1.96	51	4.268	7.631	5.842	0.044	–	–	–	–
1841-3 E	2.37	218	4.319	0.041	5.871	0.021	115.5	3.5	7.758	0.090
1841-4 E	1.88	350	4.261	0.046	5.891	0.016	112.6	3.6	7.730	0.082
1841-5 E	2.5	214	4.378	0.045	5.846	0.032	118.7	4.3	7.784	0.124
1841-6 E	2.5	12	4.428	2.744	5.881	0.044	–	–	–	–
1841-7 E	2.4	63	4.484	1.744	5.946	0.044	–	–	–	–
1841-8 E	2.14	47	4.499	2.467	5.962	0.037	–	–	–	–
Mean:
1841 E	2.25	261	4.319	0.044	5.869	0.023	115.6	3.8	7.757	0.099

Table 5

Summary table of U-Th disequilibrium ages obtained for two H. naledi teeth (samples 1788 and 1810) from the Dinaledi Chamber obtained by GU-ANU. No age calculations were carried out for U concentrations of ≤0.5 ppm or U/Th ≤250 (indicated in red and underlined). Negative U/Th values are due to the Th background being higher than the measured values. Mean values in this table only incorporate values from which meaningful ages could be calculated (indicated in black). All uncertainties are given as 2σ. CS = Closed System; Diff = diffusion (i.e., calculated ages are based on the assumption of continuous diffusion after Sambridge et al. (2012).

https://doi.org/10.7554/eLife.24231.010

Sample 1810a	U (ppm)	U/Th	²³⁰Th/²³⁸U	2σ	²³⁴U/²³⁸U	2σ	Age – CS (ka)	2σ (ka)	Age – Diff (ka)	2σ (ka)	(²³⁴U/²³⁸U)i*	2σ
1 E	0.03	−27	3.7113	1.2508	4.4302	0.8881	n/a	–	–	–	–	–
2 E	0.02	−19	3.1648	0.9390	4.2083	0.4703	n/a	–	–	–	–	–
3 E	0.04	−33	3.0257	1.0531	5.1220	0.4988	n/a	–	–	–	–	–
4 E	0.05	−35	3.6352	1.3897	4.9224	0.4912	n/a	–	–	–	–	–
5 E	0.19	−258	3.4504	0.1965	4.8106	0.1376	n/a	–	–	–	–	–
6 D	6.07	−2972	3.2909	0.0666	5.9801	0.0559	77.2	2.3	87.3	2.7	7.19	0.11
7 D	6.10	−5354	3.2618	0.0824	5.9768	0.0312	76.3	2.6	86.2	3.3	7.17	0.08
8 D	6.39	11436	3.3169	0.0800	5.9827	0.0514	77.9	2.6	88.3	3.3	7.21	0.11
9 D	6.47	6193	3.3318	0.0899	5.9470	0.0873	79.0	3.2	89.7	3.8	7.18	0.17
10 D	6.65	−5055	3.4985	0.1048	6.0462	0.0403	82.5	3.4	94.4	4.5	7.37	0.11
11 D	6.95	5149	3.5465	0.0910	6.0531	0.0406	83.8	3.0	96.3	4.0	7.40	0.11
12 D	7.15	3244	3.5238	0.0997	6.0501	0.0423	83.2	3.3	95.4	4.3	7.39	0.11
Mean:
1–5 E	0.07 ± 0.06		3.4321	0.3003	4.7962	0.1504	112.0	15.7	137.1	25.5	–	–
6–12 D	6.54 ± 0.31		3.4018	0.0749	6.0070	0.0428	80.1	2.5	91.1	3.2	7.27	0.11

Sample 1810b	U (ppm)	U/Th	²³⁰Th/²³⁸U	2σ	²³⁴U/²³⁸U	2σ	Age – CS (ka)	2σ (ka)	Age – Diff (ka)	2σ (ka)	(²³⁴U/²³⁸U)i*	2σ
1 E	0.01	17	6.8442	14.0435	0.0228	5.5626	n/a	–	–	–	–	–
2 E	0.00	3	9.2330	16.2333	−2.2838	4.6085	n/a	–	–	–	–	–
3 E	0.00	–2	16.1688	27.6564	−0.1033	7.6336	n/a	–	–	–	–	–
4 E	0.00	–3	14.9980	967.0421	−0.7695	259.2590	n/a	–	–	–	–	–
5 E	0.02	−182	7.1338	296.1136	3.6250	48.0742	n/a	–	–	–	–	–
6 E	0.86	−2493	4.5176	0.1786	4.6588	0.0795	189.1	16.7	381.3	137.9	7.24	0.44
7 E	0.98	−603	4.8797	0.1416	4.8737	0.0681	201.4	14.0	0.0	0.0	7.84	0.40
8 D	4.49	20423	3.5778	0.0670	5.9327	0.0773	87.1	2.7	100.8	3.1	7.31	0.15
9 D	5.35	−10128	3.3046	0.0659	5.9142	0.0677	78.7	2.4	89.2	2.8	7.14	0.13
10 D	5.67	−4197	3.4077	0.0777	5.9480	0.0459	81.3	2.6	92.8	3.3	7.23	0.10
Mean:
1–5 E	0.01 ± 0.01		8.7750	204.6988	1.6547	93.9630	n/a	-	-	-	-	-
6–7 E	0.92 ± 0.12		4.7101	0.1465	4.7730	0.0602	195.7	13.8	471.0	269.4	7.54	0.42
8–10 D	5.17 ± 0.70		3.4214	0.0790	5.9319	0.0523	82.1	2.7	93.7	3.6	7.23	0.13

Sample 1788a	U (ppm)	U/Th	^230th/²³⁸U	2σ	²³⁴U/²³⁸U	2σ	Age – CS (ka)	2σ (ka)	Age – Diff (ka)	2σ (ka)	(²³⁴U/²³⁸U)i*	2σ
1E	0.03	4877	2.1095	3.3058	3.5740	1.6107	n/a	–	–	–	–	–
2E	0.01	−21	3.7845	5.5271	1.3525	2.7713	n/a	–	–	–	–	–
3E	0.00	–1	10.5030	27.8940	−2.4909	10.1171	n/a	–	–	–	–	–
4E	0.00	–1	9.0249	113.8912	−0.7120	32.3636	n/a	–	–	–	–	–
5E	0.00	–2	6.6795	66.2750	0.7769	18.7506	n/a	–	–	–	–	–
6E	0.01	–6	3.0231	0.9844	2.1904	0.4875	n/a	–	–	–	–	–
7E	0.24	−105	2.8139	0.2076	6.3791	0.1624	n/a	–	–	–	–	–
8E	0.24	−204	1.6495	1.5811	6.0123	0.2961	n/a	–	–	–	–	–
9E	0.19	579	2.4075	4.2620	6.3341	1.3187	n/a	–	–	–	–	–
10E	0.48	189	3.1717	2.2862	6.1006	0.1341	n/a	–	–	–	–	–
11E	1.34	13833	3.8792	0.2864	6.3521	0.1024	88.5	9.2	102.9	12.6	7.87	0.32
12E	2.57	755	4.1770	0.0609	6.3275	0.0972	98.6	3.0	117.7	3.1	8.04	0.19
Mean:
1–6 E	0.01 ± 0.01		3.5188	4.4531	2.3471	7.1463	n/a	-	-	-	–	–
7–10 E	0.29 ± 0.13		2.6484	0.2469	6.1824	0.0978	56.2	6.5	61.0	7.7	–	–
11–12 E	1.96 ± 1.23		4.0746	0.0941	6.3361	0.0482	95.1	3.2	112.3	4.7	7.96	0.26

Sample 1788b	U (ppm)	U/Th	²³⁰Th/²³⁸U	2σ	²³⁴U/²³⁸U	2σ	Age – CS (ka)	2σ (ka)	Age – Diff (ka)	2σ (ka)	(²³⁴U/²³⁸U)i*	2σ
1E	0.02	4	2.3945	1.8774	3.5040	1.4368	n/a	–	–	–	–	–
2E	0.02	14	1.9656	1.3299	3.3099	0.9022	n/a	–	–	–	–	–
3E	0.01	–8	2.8156	2.1034	2.5359	0.8082	n/a	–	–	–	–	–
4E	0.02	160	2.1024	58.1854	3.2342	7.4009	n/a	–	–	–	–	–
5E	0.03	−31	2.3859	1.4084	4.1285	1.5222	n/a	–	–	–	–	–
6E	0.03	−20	2.8951	11.2911	4.1046	3.9747	n/a	–	–	–	–	–
7E	0.02	−10	2.8486	3.5383	4.9362	2.3343	n/a	–	–	–	–	–
8E	0.03	−18	2.8325	1.6113	5.7052	0.7139	n/a	–	–	–	–	–
Mean:
1–8 E	0.02 ± 0.01		2.5597	6.7618	4.1308	1.2209	n/a	–	–	–	–	–

Sample 1788c	U (ppm)	U/Th	^230th/²³⁸U	2σ	²³⁴U/²³⁸U	2σ	Age – CS (ka)	2σ (ka)	Age – Diff (ka)	2σ (ka)	(²³⁴U/²³⁸U)i*	2σ
1D	5.44	21578	3.9281	0.0707	6.4260	0.0740	88.6	2.6	103.0	3.1	7.97	0.15
2D	5.39	155037	3.8908	0.0565	6.4416	0.0524	87.2	2.0	101.0	2.4	7.96	0.11
3D	4.95	1708	3.8901	0.0828	6.4085	0.0792	87.8	3.0	102.0	3.6	7.93	0.16
4D	3.87	1653	3.8033	0.0859	6.3786	0.1068	85.8	3.3	99.0	3.6	7.85	0.20
5D	4.25	1168	3.9569	0.0800	6.4051	0.0957	90.0	3.1	105.0	3.6	7.97	0.19
6D	5.12	1493	3.9433	0.0579	6.4951	0.0961	87.8	2.5	102.0	2.5	8.04	0.17
7D	5.34	2659	3.8020	0.0581	6.4713	0.0581	84.0	2.0	96.7	2.4	7.94	0.11
8D	5.06	1093	3.9948	0.0672	6.4479	0.0630	90.3	2.4	105.5	3.0	8.03	0.13
9D	4.78	1018	4.0481	0.0718	6.4468	0.0586	92.0	2.5	108.0	3.3	8.06	0.13
10D	5.22	817	3.9011	0.0582	6.5187	0.0813	86.1	2.3	99.6	2.4	8.04	0.15
11D	5.25	425	3.8872	0.0850	6.4415	0.0624	87.1	2.8	101.0	3.6	7.96	0.14
12D	5.46	345	3.9561	0.0584	6.4658	0.0733	88.8	2.3	103.3	2.5	8.03	0.14
Mean:
1–12 D	5.01 ± 0.28		3.9175	0.0796	6.4479	0.0461	87.9	2.6	102.0	3.6	7.98	0.06

Table 6

Summary table of model parameters used in ESR dating separated by sample number and laboratory. See text for detailed discussion.

https://doi.org/10.7554/eLife.24231.015

Sample:	1767	1788		1810		1841
Laboratory:	SCU	SCU	Cenieh-gu	SCU	Cenieh-gu	SCU
	Enamel:
De (Gy)	194 ± 4	231 ± 8	159 ± 10	296 ± 14	232 ± 30	1676 ± 127
U (ppm)	2.52 ± 0.53	0.38 ± 0.17	0.07 ± 0.07	0.32 ± 0.12	0.16 ± 0.16	2.28 ± 0.48
²³⁴U/²³⁸U	6.21 ± 0.03	5.95 ± 0.32	6.258 ± 0.349	4.04 ± 0.18	4.773 ± 0.060	5.87 ± 0.03
²³⁰Th/²³⁴U	0.37 ± 0.05	0.55 ± 0.52	0.598 ± 0.038	0.92 ± 0.05	0.950 ± 0.034	0.785 ± 0.038
Alpha efficiency*	0.13 ± 0.02	0.13 ± 0.02	0.13 ± 0.02	0.13 ± 0.02	0.13 ± 0.02	0.13 ± 0.02
Initial thickness (μm)	1027 ± 210	1049 ± 277	1486 ± 248	1150 ± 250	1527 ± 257	650 ± 145
Water (%)	0	0	0	0	0	0
	Dentine:
U (ppm)	7.88 ± 0.66	5.76 ± 0.86	4.71 ± 0.27	9.08 ± 0.44	5.81 ± 0.37	–
²³⁴U/²³⁸U	6.28 ± 0.09	6.40 ± 0.03	6.448 ± 0.046	5.93 ± 0.03	5.969 ± 0.035	–
²³⁰Th/²³⁴U	0.35 ± 0.11	0.62 ± 0.02	0.608 ± 0.012	0.52 ± 0.09	0.572 ± 0.010	–
Water (%)	10 ± 5	10 ± 5	10 ± 5	10 ± 5	10 ± 5	–
	Sediment:
U (ppm)	3.0 ± 0.3	2.9 ± 0.1	2.9 ± 0.1	3.2 ± 0.3	3.2 ± 0.3	0.64 ± 0.06^†
Th (ppm)	7.9 ± 0.4	8.3 ± 0.6	8.3 ± 0.6	8.6 ± 0.4	8.6 ± 0.4	4.72 ± 0.47^†
K (%)	1.17 ± 0.14	1.21 ± 0.14	1.21 ± 0.14	1.23 ± 0.14	1.23 ± 0.14	1.47 ± 0.15^†
Water (%)	25 ± 10	25 ± 10	25 ± 10	25 ± 10	25 ± 10	25 ± 10
Depth below ground surface (cm)	0	2	2	5	5	55
Gamma Dose rate (μGy a⁻¹)
25 ± 10% Water, 80% Rn degassing 25 ± 10% Water, no Rn degassing	534 ± 69 724 ± 116	534 ± 69 724 ± 116	534 ± 69 724 ± 116	534 ± 69 724 ± 116	534 ± 69 724 ± 116	534 ± 69 724 ± 116
Cosmic dose rate (μGy a⁻¹)	15 ± 1	15 ± 1	15 ± 1	15 ± 1	15 ± 1	15 ± 1

*After Woodroffe et al. (1991);
^†A relative error of ± 10% was assumed.

Table 7

Summary of ESR dating results (2σ uncertainties) for two end-member scenarios: (i) complete burial of the samples, 80% Rn loss in the sediment and post Th-230 equilibrium in dental tissue (i.e., maximum age scenario); (ii) complete burial of the samples and post-Rn equilibrium in sediment (i.e., minimum age scenario). See text for detailed discussion.

https://doi.org/10.7554/eLife.24231.016

Sample:	1767	1788		1810		1841
Laboratory:	SCU	SCU	Cenieh-gu	SCU	Cenieh-gu	SCU
Scenario 1: 25 ± 10% Water, complete burial and 80% ²²²Rn degassing (maximum age scenario)
internal dose rate (μGy a⁻¹)	1142 ± 515	190 ± 129	47 ± 47	323 ± 175	176 ± 176	1411 ± 596
alpha (μGy a⁻¹)*	0	0	8 ± 2	0	8 ± 2	0^†
beta dose rate, dentine (μGy a⁻¹)	73 ± 33	91 ± 62	64 ± 16	75 ± 41	51 ± 14	–^‡
beta dose rate, sediment (μGy a⁻¹)	101 ± 24	105 ± 31	86 ± 17	95 ± 24	86 ± 18	358 ± 74
gamma and cosmic (μGy a⁻¹)	549 ± 69	549 ± 69	549 ± 69	549 ± 69	549 ± 69	549 ± 69
total dose rate (μGy a⁻¹)	1865 ± 521	935 ± 162	754 ± 87	1042 ± 194	870 ± 190	2318 ± 606
p enamel	−0.03	0.49	−0.02	−0.70	−0.77	0.91
p dentine	0.08	0.13	−0.06	1.02	0.54	–
Age (ka)	104 ± 29	247 ± 42	211 ± 28	284 ± 51	267 ± 68	723 ± 181
Combined SCU/CENIEH-GU age (ka)		229 + 60/–46		276 + 59/–77
Average age for 1788 & 1810 (ka)		253 + 82/–70
Scenario 2: 25 ± 10% Water, complete burial and no ²²²Rn degassing (minimum age scenario)
internal dose rate (μGy a⁻¹)	1277 ± 552	216 ± 165	51 ± 51	335 ± 193	184 ± 184	1520 ± 630
alpha (μGy a⁻¹)*	0	0	8 ± 2	0	8 ± 2	0
beta dose rate, dentine (μGy a⁻¹)	82 ± 35	102 ± 78	69 ± 18	87 ± 50	59 ± 16	--
beta dose rate, sediment (μGy a⁻¹)	132 ± 26	134 ± 33	111 ± 19	126 ± 26	112 ± 19	380 ± 81
gamma and cosmic (μGy a⁻¹)	739 ± 116	739 ± 116	739 ± 116	739 ± 116	739 ± 116	739 ± 116
total dose rate (μGy a⁻¹)	2230 ± 586	1191 ± 219	978 ± 129	1287 ± 232	1102 ± 219	2639 ± 647
p enamel	−0.31	0.06	−0.37	−0.83	−0.91	0.67
p dentine	−0.22	−0.22	−0.40	0.54	0.10	–
Age (ka)	87 ± 22	194 ± 34	163 ± 24	230 ± 40	210 ± 50	635 ± 148
Combined SCU/CENIEH-GU age (ka)		179 + 49/–40		220 + 50/–60
Average age for 1788 & 1810 (ka)		200 + 70/–61

*using alpha attenuation values of Grün (1987).
^†considered as negligible given the low radioelement concentrations in the sediment and the high total dose rate value.
^‡for 1841, the beta dose rate on both sides of the enamel layer is derived from the sediment.

Table 8

Summary of OSL results obtained by the University of the Witwatersrand for samples of Unit 1 from the Dinaledi Chamber (samples OSL3, 4 and 5). The ages were calculated using effective U concentration values (taking disequilibrium into account; see text for details). CAM = Central Age Model; MAM = Minimum Age Model.

https://doi.org/10.7554/eLife.24231.017

Sample ID	H₂O (%)	Th (ppm)	U (ppm) pre-Rn	U (ppm) post-Rn	K (%)	Total dr (Gy/ka)	2σ	Total de (Gy) CAM	2σ	Total de (Gy) MAM	2σ	CAM Age (ka)	CAM 2σ	MAM age (ka)	MAM 2σ	Over dispersion (%)
OSL3	18.9 ± 5	3.71 ± 1.60	0.75 ± 0.177	0.193 ± 0.044	0.45 ± 0.12	0.76	0.07	428.59	68.92	176.4	27.7	560	103	231	41	63
OSL4	25.8 ± 5	3.38 ± 1.60	0.485 ± 0.177	0.097 ± 0.044	0.47 ± 0.12	0.70	0.06	379.89	43.58	168.0	20.7	546	79	241	37	55
OSL5	22.7 ± 5	5.11 ± 1.60	0.692 ± 0.177	0.138 ± 0.044	0.56 ± 0.12	0.90	0.07	759.54	102.33	315.67	48.68	849	132	353	61	68

Table 9

Final mean palaeomagnetic data for all subsamples analysed from each phase of Flowstone 1a as shown in Figure 13. MAD = mean maximum angular deviation for individual samples; K = precision/sample dispersal parameter; Plat = palaeolatitude).

https://doi.org/10.7554/eLife.24231.018

Flowstone 1a	Declination (^O)	Inclination (^O)	MAD	K	Plat.	Polarity
Phase C	15.5	−39.7	3	70.8	75.4	N
Phase B	26	−28.1	7.4	156.2	63.3	N
Phase A	156.4	15.9	5.7	30.2	−60.0	R

Table 10

ESR fitting results obtained by SCU and CENIEH-GU. Both laboratories employed a Single Saturating Exponential (SSE) fitting function. D_max was selected in accordance with Duval and Grün (2016) to avoid D_E overestimation. SCU results in brackets show D_E values that were obtained by SCU using the CENIEH-GU procedure (see text for details).

https://doi.org/10.7554/eLife.24231.022

	SCU			Cenieh-gu
Sample	D_E (Gy)	D_max (Gy)	D_max/D_E	D_E (Gy)	D_max (Gy)	D_max/D_E
1767	194 ± 4 (193 ± 6)	1264	7	–	–	–
1788	232 ± 8 (232 ± 22)	1204	5	159 ± 11	1649	10
1810	296 ± 14 (281 ± 34)	2735	9	232 ± 29	1649	7
1841	1676 ± 127 (1648 ± 500)	3526	2	–	–	–

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Article PDF

Open citations (links to open the citations from this article in various online reference manager services)

Mendeley

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

Paul HGM Dirks
Eric M Roberts
Hannah Hilbert-Wolf
Jan D Kramers
John Hawks
Anthony Dosseto
Mathieu Duval
Marina Elliott
Mary Evans
Rainer Grün
John Hellstrom
Andy IR Herries
Renaud Joannes-Boyau
Tebogo V Makhubela
Christa J Placzek
Jessie Robbins
Carl Spandler
Jelle Wiersma
Jon Woodhead
Lee R Berger

(2017)

The age of Homo naledi and associated sediments in the Rising Star Cave, South Africa

eLife 6:e24231.

https://doi.org/10.7554/eLife.24231

Figures

Location of Rising Star Cave and the Dinaledi Chamber.

Geological face map and cross-sections through the sediment pile at different locations in the Dinaledi Chamber, illustrating the relationships between the flowstone groups and sedimentary units.

Field and close-up photographs of all flowstone samples collected for U-Th dating.

Location of the three H. naledi tooth samples (samples 1767, 1788 and 1810) and one baboon (cf. Papio) tooth sample (sample 1841) used for combined U-series and ESR dating.

Samples of orange laminated mudstone of Unit 1 for OSL dating.

Photographs of H. naledi teeth used for ESR dating.

Photographs of the baboon (cf. Papio) tooth (sample 1841), recovered from the sondage in the excavation pit, and used for ESR dating.

Cartoon illustrating the sedimentary history resulting in the deposition and redistribution of sediment of Units 2 and 3, and Flowstone Groups 1 to 3 in the Dinaledi Chamber.

Photographs illustrating the sampling approaches taken by SCU-UoW and GU-ANU in obtaining the U-Th results presented in Tables 4 and 5.

Gamma dose rate reconstructions derived from analytical data of sediment samples collected around ESR samples 1767, 1788 and 1810 (closed circles and diamonds), combined with samples from a vertical profile in the excavation pit and sondage (open circles and diamonds).

ESR dose response curves (DRC’s) obtained for the samples 1767, 1788, 1810 and 1841.

Evolution of the I_max/I_min ratio vs the irradiation dose for the four tooth samples.

Samples and results of palaeomagnetic analyses forFlowstone 1a.

Chronostratigraphic summary of radio-isotopic dating results, and interpretation of the depositional ranges of stratigraphic units, flowstones and H.

Tables

Download links

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

Be the first to read new articles from eLife

Share this article

Cite this article

Location of Rising Star Cave and the Dinaledi Chamber.

Geological face map and cross-sections through the sediment pile at different locations in the Dinaledi Chamber, illustrating the relationships between the flowstone groups and sedimentary units.

Field and close-up photographs of all flowstone samples collected for U-Th dating.

Location of the three H. naledi tooth samples (samples 1767, 1788 and 1810) and one baboon (cf. Papio) tooth sample (sample 1841) used for combined U-series and ESR dating.

Samples of orange laminated mudstone of Unit 1 for OSL dating.

Photographs of H. naledi teeth used for ESR dating.

Photographs of the baboon (cf. Papio) tooth (sample 1841), recovered from the sondage in the excavation pit, and used for ESR dating.

Cartoon illustrating the sedimentary history resulting in the deposition and redistribution of sediment of Units 2 and 3, and Flowstone Groups 1 to 3 in the Dinaledi Chamber.

Photographs illustrating the sampling approaches taken by SCU-UoW and GU-ANU in obtaining the U-Th results presented in Tables 4 and 5.

Gamma dose rate reconstructions derived from analytical data of sediment samples collected around ESR samples 1767, 1788 and 1810 (closed circles and diamonds), combined with samples from a vertical profile in the excavation pit and sondage (open circles and diamonds).

ESR dose response curves (DRC’s) obtained for the samples 1767, 1788, 1810 and 1841.

Evolution of the Imax/Imin ratio vs the irradiation dose for the four tooth samples.

Samples and results of palaeomagnetic analyses forFlowstone 1a.

Chronostratigraphic summary of radio-isotopic dating results, and interpretation of the depositional ranges of stratigraphic units, flowstones and H.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

Evolution of the I_max/I_min ratio vs the irradiation dose for the four tooth samples.