Soleimani, Mojgan; Nadimi, Alireza; Koltai, Gabriella; Dublyansky, Yuri; Carolin, Stacy A; Spötl, Christoph (2023): Measured isotope activity ratios, calculated ages and monte-carlo derived age error, and Oxcal deposition model U-Th ages and associated age error of the stalagmite SIB-4 from Sibaki Cave, Southwestern Iran [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.955974, In: Soleimani, M et al. (2023): U/Th, age model and stable isotope data from the Last Glacial Maximum to the Early Holocene in Sibaki Cave, Southwestern Iran [dataset bundled publication]. PANGAEA, https://doi.org/10.1594/PANGAEA.955861
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Published: 2023-02-22 • DOI registered: 2023-04-19
Abstract:
A total of 32 230Th ages were measured along the growth axis of SIB-4 stalagmite. 100-200 mg of calcite powder was drilled per sample in a laminar-flow hood following growth lamina. The samples were chemically prepared at the Department of Earth Sciences, University of Oxford. The samples were spiked with a mixed 229Th-236U spike, dissolved in HNO3 and refluxed on a hot-plate overnight for spike-sample equilibration. Chemical separation of U and Th was done following procedures adapted from Edwards et al. (1987). The separated U and Th fractions were analysed on a Nu Plasma multi-collector inductively coupled plasma mass spectrometer, following the procedure described in Carolin et al. (2019). Individual 230Th ages with their 95% confidence intervals were calculated using an in-house Monte Carlo script that incorporates chemical blank errors, analytical uncertainties and initial 230Th/232Th uncertainties. The initial 230Th/232Th (atomic ratio) is estimated to be between 0.5 to 10.8 ppm (uniform distribution), equivalent to an activity ratio of 0.1 to 2.0. This range encompasses both the bulk earth value (230Th/232Th activity = 0.82) and the median detritus value calculated in a collection of speleothem studies (230Th/232Th activity = 1.5) (Hellstrom, 2006). Notably, SIB-4 samples exhibit large 230Th/232Th, with 90% of samples showing 230Th/232Th activity greater than 1000. This is due to high U content and low detrital Th content of the stalagmite. Thus, the age corrections related to detrital contamination are small (median of just 4 years), which is much less than the overall age error of ca. 100 years (2s).
Related to:
Soleimani, Mojgan; Nadimi, Alireza; Koltai, Gabriella; Dublyansky, Yuri; Carolin, Stacy A; Spötl, Christoph (2022): Stalagmite evidence of Last Glacial Maximum to early Holocene climate variability in southwestern Iran. Journal of Quaternary Science, jqs.3478, https://doi.org/10.1002/jqs.3478
Other version:
Soleimani, Mojgan; Nadimi, Alireza; Koltai, Gabriella; Dublyansky, Yuri; Carolin, Stacy A; Spötl, Christoph (2022): NOAA/WDS Paleoclimatology - Sibaki Cave, Iran U/Th Age Model and Stable Isotope Data from the Last Glacial Maximum to the Early Holocene [dataset]. NOAA National Centers for Environmental Information, https://doi.org/10.25921/XPYJ-M346
References:
Carolin, Stacy A; Ersek, Vasile; Roberts, William H G; Walker, Richard T; Henderson, G M (2019): Drying in the Middle East During Northern Hemisphere Cold Events of the Early Glacial Period. Geophysical Research Letters, 46(23), 14003-14010, https://doi.org/10.1029/2019GL084365
Cheng, Hai; Edwards, R Lawrence; Shen, Chuan-Chou; Polyak, Victor J; Asmerom, Yemane; Woodhead, Jon D; Hellstrom, John C; Wang, Yongjin; Kong, Xinggong; Spötl, Christoph; Wang, Xianfeng; Alexander, E Calvin (2013): Improvements in 230Th dating, 230Th and 234U half-life values, and U–Th isotopic measurements by multi-collector inductively coupled plasma mass spectrometry. Earth and Planetary Science Letters, 371-372, 82-91, https://doi.org/10.1016/j.epsl.2013.04.006
Edwards, R Lawrence; Chen, J H; Wasserburg, Gerald J (1987): 238U-234U-230Th-232Th systematics and the precise measurement of time over the past 500,000 years. Earth and Planetary Science Letters, 81(2-3), 175-192, https://doi.org/10.1016/0012-821X(87)90154-3
Hellstrom, John C (2006): U–Th dating of speleothems with high initial 230Th using stratigraphical constraint. Quaternary Geochronology, 1(4), 289-295, https://doi.org/10.1016/j.quageo.2007.01.004
Coverage:
Latitude: 29.815080 * Longitude: 51.596390
Minimum DISTANCE: 0.3 cm * Maximum DISTANCE: 47.8 cm
Event(s):
Parameter(s):
| # | Name | Short Name | Unit | Principal Investigator | Method/Device | Comment |
|---|---|---|---|---|---|---|
| 1 | Substage | Substage | Soleimani, Mojgan | ID of individual growth sections of SIB-4, separated by growth axis change (see article text) | ||
| 2 | Sample ID | Sample ID | Soleimani, Mojgan | UTh_sample_ID: U-Th sample ID labels begin with a two-letter pair (aa, ab, etc.) that define a U-Th batch of samples followed by a two-digit number specifying the sample number in the particular batch | ||
| 3 | Sample ID | Sample ID | Soleimani, Mojgan | stal_sample_ID: Stalagmite sample ID including stalagmite name and drilling number | ||
| 4 | DISTANCE | Distance | cm | Soleimani, Mojgan | Geocode – total distance along growth axes from the top of the stalagmite | |
| 5 | DISTANCE | Distance | cm | Soleimani, Mojgan | Geocode – distance along growth axis within a single substage of SIB-4 | |
| 6 | Uranium-238 | 238U | µg/kg | Soleimani, Mojgan | Multiple collector inductively-coupled plasma mass spectrometer (MC-ICP-MS), Nu | ppb |
| 7 | Thorium-232 | 232Th | µg/kg | Soleimani, Mojgan | Multiple collector inductively-coupled plasma mass spectrometer (MC-ICP-MS), Nu | ppb |
| 8 | Thorium-232/Thorium-230 ratio | 232Th/230Th | Soleimani, Mojgan | Multiple collector inductively-coupled plasma mass spectrometer (MC-ICP-MS), Nu | ||
| 9 | Uranium-234/Uranium-238 activity ratio | (234U/238U) | Soleimani, Mojgan | Multiple collector inductively-coupled plasma mass spectrometer (MC-ICP-MS), Nu | ||
| 10 | Uranium-234/Uranium-238 activity ratio, standard deviation | (234U/238U) std dev | ± | Soleimani, Mojgan | Multiple collector inductively-coupled plasma mass spectrometer (MC-ICP-MS), Nu | 2s |
| 11 | Thorium-230/Uranium-238 activity ratio | (230Th/238U) | Soleimani, Mojgan | Multiple collector inductively-coupled plasma mass spectrometer (MC-ICP-MS), Nu | ||
| 12 | Thorium-230/Uranium-238 activity ratio, standard deviation | (230Th/238U) std dev | ± | Soleimani, Mojgan | Multiple collector inductively-coupled plasma mass spectrometer (MC-ICP-MS), Nu | 2s |
| 13 | Thorium-232/Uranium-238 activity ratio | (232Th/238U) | Soleimani, Mojgan | Multiple collector inductively-coupled plasma mass spectrometer (MC-ICP-MS), Nu | ||
| 14 | Thorium-232/Uranium-238 activity ratio, standard deviation | (232Th/238U) std dev | ± | Soleimani, Mojgan | Multiple collector inductively-coupled plasma mass spectrometer (MC-ICP-MS), Nu | 2s |
| 15 | Year of analysis | Year analysis | a AD | Soleimani, Mojgan | year samples were measured on the MC-ICP-MS (C.E.) | |
| 16 | Age, dated | Age dated | ka BP | Soleimani, Mojgan | Age, Uranium-Thorium, uncorrected | calculated age not corrected for initial 230Th from detrital contaminants, in kiloyears before 1950 CE. All ages calculated using half-lives found in Cheng et al. (2013) |
| 17 | Thorium-230/Thorium-232 ratio (0) | 230Th/232Th(0) | Soleimani, Mojgan | Multiple collector inductively-coupled plasma mass spectrometer (MC-ICP-MS), Nu | minimum of initial 230Th/232Th atomic ratio (uniform distribution) used to calculate corrected age | |
| 18 | Thorium-230/Thorium-232 ratio (0) | 230Th/232Th(0) | Soleimani, Mojgan | Multiple collector inductively-coupled plasma mass spectrometer (MC-ICP-MS), Nu | maximum of initial 230Th/232Th atomic ratio (uniform distribution) used to calculate corrected age | |
| 19 | Calendar age | Cal age | ka BP | Soleimani, Mojgan | Monte Carlo method | calculated age corrected for initial 230Th from detrital contaminants, in kiloyears before 1950 CE. All ages calculated using half-lives found in Cheng et al. (2013). |
| 20 | Calendar age, error to older | Cal age e + | ka BP | Soleimani, Mojgan | Monte Carlo method | 2s: Upper 95% confidence interval minus the mean age. 95% confidence interval calculated using an internally developed Monte Carlo simulation with N=1e4 |
| 21 | Calendar age, error to younger | Cal age e - | ka BP | Soleimani, Mojgan | Monte Carlo method | 2s: Mean age minus the lower 95% confidence interval. 95% confidence interval calculated using an internally developed Monte Carlo simulation with N=1e4 |
| 22 | Uranium-234/Uranium-238 activity ratio (0) | 234U/238U(0) | Soleimani, Mojgan | Calculated, using the corrected age | Initial (234/238) | |
| 23 | Uranium-234/Uranium-238 activity ratio (0), positive error | (234U/238U(0)) e+ | Soleimani, Mojgan | Calculated, using the corrected age | Upper 95% confidence interval minus the mean for the initial (234/238) | |
| 24 | Uranium-234/Uranium-238 activity ratio (0), negative error | (234U/238U(0)) e- | Soleimani, Mojgan | Calculated, using the corrected age | Mean minus the lower 95% confidence interval for the initial (234/238) | |
| 25 | Calendar age | Cal age | ka BP | Soleimani, Mojgan | OxCal 4.4 Poisson-process deposition model feature | mean age, kiloyears before 1950 |
| 26 | Calendar age, maximum/old | Cal age max | ka BP | Soleimani, Mojgan | OxCal 4.4 Poisson-process deposition model feature | 95% confidence range, kiloyears before 1950 |
| 27 | Calendar age, minimum/young | Cal age min | ka BP | Soleimani, Mojgan | OxCal 4.4 Poisson-process deposition model feature | 95% confidence range, kiloyears before 1950 |
License:
Creative Commons Attribution 4.0 International (CC-BY-4.0)
Status:
Curation Level: Enhanced curation (CurationLevelC) * Processing Level: PANGAEA data processing level 3 (ProcLevel3)
Size:
800 data points