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Official Journal of the Asia Oceania Geosciences Society (AOGS)

Geoscience Letters Cover Image

Table 1 U-Th isotopic compositions and 230Th ages for corals of Badoc Island by MC-ICPMS, Thermo Electron Neptune, at HISPEC, NTU

From: Occurrence of 1 ka-old corals on an uplifted reef terrace in west Luzon, Philippines: Implications for a prehistoric extreme wave event in the South China Sea region

Sample ID Weight g 238U ppba 232Th ppt d234U measureda [230Th/238U] activityc 230Th/232Th atomic (×10−6) Age (year ago) uncorrected Age (year ago) correctedc,d Age (year BP) relative to 1950 AD δ234Uinitial correctedb
BAD-071914-2.1 0.26321 2324.0 ± 3.6 30.3 ± 1.8 145.2 ± 2.2 0.07067 ± 0.00017 89,269 ± 5199 6937 ± 22 6936 ± 22 6871.7 ± 22 148.1 ± 2.2
BAD-071914-2.2 0.20931 3151.7 ± 4.7 595.6 ± 2.6 147.2 ± 2.1 0.010623 ± 0.000038 926.8 ± 5.0 1014.3 ± 4.1 1009.9 ± 4.6 945.1 ± 4.6 147.6 ± 2.1
BAD-071914-2.3 0.21320 3130.4 ± 5.1 161.0 ± 2.2 143.4 ± 2.3 0.010119 ± 0.000035 3245 ± 46 969.2 ± 3.9 968.0 ± 3.9 903.1 ± 3.9 143.8 ± 2.3
BAD-022215-09 0.10863 2564.8 ± 2.4 27.5 ± 4.3 144.8 ± 1.4 0.0145 ± 0.0001 22293 ± 3471 1387 ± 5 1386.6 ± 5.4 1320 ± 5 145.4 ± 1.4
BAD-111815-01 0.14431 3374.9 ± 2.9 69.6 ± 3.2 145.4 ± 1.3 0.02898 ± 0.00013 23170 ± 1079 2793 ± 13 2793 ± 13 2727 ± 13 146.6 ± 1.4
  1. Decay constants are 9.1705 × 10−6 year−1 for 230Th, 2.8221 × 10−6 year−1 for 234U (Cheng et al. 2013), and 1.55125 × 10−10 year−1 for 238U (Jaffey et al. 1971)
  2. a[238U] = [235U] × 137.77 (±0.11‰) (Hiess et al. 2012); δ234U = ([234U/238U]activity − 1) × 1000
  3. bδ234Uinitial corrected was calculated based on 230Th age (T), i.e., δ234Uinitial = δ234Umeasured X eλ234*T, and T is corrected age
  4. c[230Th/238U]activity = 1 − e−λ230T + (δ234Umeasured/1000)[λ230/(λ230 − λ234)](1 − e−(λ230 − λ234) T), where T is the age
  5. dAge corrections, relative to chemistry date, were calculated using an estimated atomic 230Th/232Th ratio of 4 (±2) × 10−6 (Shen et al. 2008)