Table 1. Summary of U-Th zircon ages.

Crystal name	Depth (µm)	(238U)/(232Th)	±1σ	(230Th)/(232Th)	±1σ	U (ppm)	Age (ka)	+1σ (ka)	−1σ (ka)
HD-10	0–5	4.403	0.071	1.752	0.146	274	30.7	6.2	−5.9
HD-11	0–5	4.762	0.083	3.244	0.314	169	102	26	−21
HD-12	0–5	4.439	0.030	1.760	0.157	260	30.6	6.6	−6.2
HD-13	0–5	5.054	0.057	1.638	0.293	304	21.6	9.8	−9.0
HD-1	0–5	3.865	0.064	1.755	0.096	535	37.4	5.2	−4.9
HD-2	0–5	4.363	0.064	1.557	0.091	369	23.2	3.6	−3.5
HD-3	0–5	6.622	0.114	2.114	0.197	226	26.2	4.9	−4.7
HD-4	0–5	6.130	0.062	2.071	0.238	161	27.8	6.6	−6.2
HD-5	0–5	4.527	0.150	3.241	0.165	250	113	18	−15
HD-6	0–5	5.176	0.068	3.056	0.207	319	76.8	11.4	−10.3
HD-7	0–5	4.069	0.093	4.007	0.151	435	431	∞	−148
HD-8	0–5	3.935	0.042	3.039	0.140	274	133	19	−16
HD-9	0–5	4.312	0.055	1.716	0.148	191	30.1	6.4	−6.1
HD-n1	0–5	4.393	0.042	1.388	0.140	253	16.7	5.2	−5.0
HD-n2	0–5	6.459	0.080	2.298	0.268	171	31.8	7.3	−6.8
HD-n3	0–5	7.030	0.112	2.541	0.275	173	34.2	6.9	−6.5
HD-n4	0–5	4.101	0.046	3.138	0.180	184	131	23	−19
HD-n5	0–5	5.905	0.045	1.835	0.234	136	22.7	6.5	−6.1
HD-n6	0–5	4.216	0.053	3.346	0.142	342	146	20	−17
HD-n7	0–5	6.254	0.086	5.473	0.343	139	210	65	−41
HD-n8	0–5	6.448	0.082	1.705	0.258	194	17.3	6.1	−5.8
HD-n9	0–5	4.005	0.056	1.800	0.212	176	37.6	11.1	−10.0
HD-n10	0–5	5.240	0.054	1.964	0.203	140	30.9	7.0	−6.6
HD-n11	0–5	3.878	0.039	3.565	0.193	208	246	108	−53
HD-n12	0–5	4.019	0.034	1.764	0.129	192	35.7	6.5	−6.1
HD-n13	0–5	3.935	0.022	2.304	0.184	187	68.1	13.1	−11.7
HD-n14	0–5	4.742	0.232	2.380	0.218	281	53.3	11.5	−10.4
HD-n15	0–5	4.773	0.053	2.945	0.139	328	82.2	8.8	−8.1
HD-n16	0–5	4.025	0.056	1.456	0.128	212	21.6	5.6	−5.3
HD-n17	0–5	3.434	0.096	1.634	0.153	187	37.7	9.9	−9.1
HD-n18	0–5	7.047	0.116	2.328	0.255	156	29.0	6.1	−5.8
HD-n19	0–5	6.636	0.067	3.497	0.379	276	66.0	14.1	−12.5
HD-n20	0–5	6.223	0.062	5.374	0.390	151	201	68	−42
HD-n1	20–25	4.146	0.021	2.742	0.254	85	91.8	21.8	−18.2
HD-n2	20–25	5.274	0.026	2.250	0.213	118	40.5	8.0	−7.4
HD-n4	20–25	2.253	0.010	2.493	0.169	78	∞	∞	∞
HD-n6	20–25	7.064	0.031	7.694	0.512	77	∞	∞	∞
HD-n8	20–25	4.987	0.024	1.657	0.255	84	22.6	8.7	−8.1
HD-n9	20–25	3.777	0.019	1.950	0.221	127	49.8	14.1	−12.5
HD-n12	20–25	4.284	0.030	2.046	0.193	70	45.4	9.9	−9.1
HD-n13	20–25	4.689	0.024	3.534	0.398	34	130	46	−32
HD-n14	20–25	4.258	0.022	4.230	0.220	176	521	∞	−237
HD-n15	20–25	4.813	0.060	4.751	0.456	116	453	∞	−233
HD-n16	20–25	6.068	0.027	3.354	0.410	63	70.5	17.9	−15.4
HD-n19	20–25	4.714	0.029	3.075	0.396	36	92.5	30.2	−23.6
HD-n20	20–25	5.843	0.029	6.364	0.502	102	∞	∞	∞
HDA-1	0–5	3.587	0.032	3.045	0.173	181	176	42	−30
HDA-10	0–5	3.584	0.044	2.102	0.152	300	66.0	11.9	−10.7
HDA-11	0–5	4.771	0.114	4.222	0.193	390	214	55	−36
HDA-12	0–5	6.045	0.030	2.520	0.180	362	41.9	5.7	−5.4
HDA-13	0–5	5.496	0.062	2.712	0.342	114	55.4	14.4	−12.7
HDA-14	0–5	3.734	0.021	3.477	0.110	475	263	62	−39
HDA-15	0–5	3.950	0.035	3.053	0.187	152	135	26	−21
HDA-16	0–5	3.814	0.044	1.898	0.141	183	46.8	8.4	−7.8
HDA-17	0–5	5.663	0.087	2.260	0.385	89	37.4	13.1	−11.7
HDA-18	0–5	4.343	0.085	3.611	0.228	195	170	43	−31
HDA-2	0–5	4.329	0.028	2.228	0.195	147	54.4	10.7	−9.7
HDA-3	0–5	4.720	0.154	2.040	0.158	161	39.5	6.9	−6.5
HDA-4	0–5	3.616	0.027	1.861	0.136	291	48.8	8.8	−8.2
HDA-5	0–5	4.505	0.063	2.790	0.132	306	82.0	9.0	−8.3
HDA-6	0–5	3.423	0.026	2.659	0.173	176	132	28	−22
HDA-7	0–5	5.790	0.029	3.132	0.254	159	67.2	11.0	−10.0
HDA-8	0–5	4.046	0.040	1.986	0.154	186	47.2	8.5	−7.9
HDA-9	0–5	4.165	0.056	2.092	0.182	172	50.6	10.1	−9.3
HDA-n1	0–5	6.349	0.049	3.119	0.261	176	57.7	9.2	−8.5
HDA-n2	0–5	8.424	0.101	4.913	0.510	90	83.7	17.2	−14.9
HDA-n3	0–5	4.610	0.076	2.510	0.250	158	63.0	14.0	−12.4
HDA-n4	0–5	3.887	0.047	3.611	0.265	248	261	396	−74
HDA-n5	0–5	8.122	0.039	2.811	0.486	83	34.0	10.5	−9.6
HDA-n6	0–5	4.686	0.089	1.905	0.209	107	34.5	8.6	−8.0
HDA-n7	0–5	3.349	0.219	3.432	0.266	284	∞	∞	∞
HDA-n8	0–5	3.873	0.023	2.028	0.150	176	53.1	9.3	−8.5
HDA-n9	0–5	3.822	0.028	2.398	0.148	264	79.5	12.1	−10.9
HDA-n10	0–5	5.173	0.167	3.275	0.458	104	89.4	30.9	−24.0
HDA-n11	0–5	3.861	0.042	3.302	0.183	221	183	44	−31
HDA-n12	0–5	7.455	0.063	5.569	0.476	98	136	32	−25
HDA-n13	0–5	4.188	0.060	2.558	0.202	210	77.6	14.6	−12.9
HDA-n1	20–25	4.711	0.026	3.219	0.417	140	103	36	−27
HDA-n2	20–25	4.264	0.024	4.044	0.273	157	299	∞	−88
HDA-n3	20–25	4.067	0.118	3.694	0.413	167	235	∞	−83
HDA-n5	20–25	4.391	0.049	4.081	0.358	183	265	∞	−84
HDA-n6	20–25	3.833	0.021	3.761	0.315	135	406	∞	−184
HDA-n8	20–25	4.770	0.032	4.239	0.263	244	218	75	−44
HDA-n9	20–25	3.175	0.017	2.781	0.136	439	193	46	−33
HDA-n10	20–25	4.630	0.024	4.640	0.292	238	∞	∞	∞
HDA-n11	20–25	4.126	0.024	4.471	0.322	209	∞	∞	∞
HDA-n12	20–25	6.265	0.133	6.324	0.450	137	∞	∞	∞
HDA-n13	20–25	5.418	0.026	4.769	0.309	202	213	71	−43
HDA-n14	20–25	3.065	0.050	1.881	0.098	486	67.3	9.7	−8.9
HDA-n15	20–25	3.130	0.033	2.919	0.124	445	259	102	−52
HDA-n16	20–25	5.238	0.024	4.044	0.458	109	142	53	−35

all uncertainties 1σ; decay constants used: λ₂₃₀∶9.1577×10⁻⁶ a⁻¹; λ₂₃₂∶4.9475·10⁻¹¹ a⁻¹; λ₂₃₈∶1.55125·10⁻¹⁰ a⁻¹; age = zircon-melt two point isochron age for melt = (²³⁸U)/(²³²Th) = (²³⁰Th)/(²³²Th) = 0.882±0.015; ∞ secular equilibrium; sampling locations: HD = 36S 602261E/4220954N; HDA = 36S 599557E/4215676N (UTM/WGS84).