Siders Pond (Falmouth)
Massachusetts, Cape Cod, Falmouth, United States
Other media
- Type
- Other medium
Coastal kettle pond of 13.4 ha and 15 m depth, connected to Vineyard Sound by a channel and fed with fresh water by rain and urban runoff: oxygenated surface waters over salty, anoxic and sulphidic deep waters. Three sampling seasons (2019 to 2021): highly variable surface dissolved Tl (9 to 42 pM), drawn down with preferential removal of the light isotope, possibly by biological uptake; Mn oxides with no net effect on dissolved Tl; below the oxycline, rapid Tl removal with particulate sulphides (correlated with Mo and Cd) without resolvable fractionation. Sediments record the mean ε205Tl of the overlying waters, supporting the palaeo-oxygenation proxy (Ostrander et al., 2023). Pond coordinates after Mapcarta.
ε205Tl in ε units (parts per 10,000) Values of the same system
Standard : NIST SRM 997
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| −2.27 ± 1.48 ε | −3.85 / −0.05 ε | 13 | oxic surface waters, dissolved oxygen 0.5 mg/L or more (dissolved Tl) Mean and standard deviation recalculated from 13 analyses, large day-to-day variability, highest values on 14/08/2020 (pH 9, 4 to 9 pM Tl); values by date and depth: 14/08/2020 at 0 m: -0.45; 14/08/2020 at 1 m: -0.54; 14/08/2020 at 2 m: -0.67; 14/08/2020 at 3 m: -0.05; 14/08/2020 at 3.5 m: -1.00; 17/09/2020 at 0 m: -3.58; 17/09/2020 at 1 m: -3.49; 17/09/2020 at 2 m: -3.33; 07/11/2020 at 0 m: -3.74; 07/11/2020 at 1 m: -3.85; 15/07/2021 at 0 m: -3.54; 15/07/2021 at 1 m: -2.70; 15/07/2021 at 2 m: -2.56. | Ostrander et al. (2023), Thallium isotope cycling between waters, particles, and sediment… |
| −3.06 ± 0.63 ε | −4 / −2.27 ε | 9 | anoxic sulphidic waters, dissolved oxygen below 0.5 mg/L (dissolved Tl) Mean and standard deviation recalculated from 9 analyses, dissolved Tl of 1 to 6 pM, rapidly removed below the oxycline; values by date and depth: 14/08/2020 at 4 m: -2.65; 14/08/2020 at 6 m: -2.89; 14/08/2020 at 7 m: -3.37; 14/08/2020 at 8 m: -3.99; 15/07/2021 at 3 m: -2.27; 15/07/2021 at 4 m: -3.19; 15/07/2021 at 5 m: -2.61; 15/07/2021 at 6 m: -2.54; 15/07/2021 at 9 m: -4.00. | Ostrander et al. (2023), Thallium isotope cycling between waters, particles, and sediment… |
| −2.87 ± 2.43 ε | −5.52 / 0.93 ε | 9 | particles of oxic surface waters Mean and standard deviation recalculated from 9 analyses, +0.93 and +0.83 on 17/09/2020, the day of peak particulate Mn oxides (1.7 µM); values by date and depth: 17/09/2020 at 0 m: +0.93; 17/09/2020 at 1 m: +0.83; 17/09/2020 at 2 m: -1.86; 07/11/2020 at 0 m: -3.02; 07/11/2020 at 1 m: -3.15; 07/11/2020 at 2 m: -4.62; 15/07/2021 at 0 m: -4.00; 15/07/2021 at 1 m: -5.41; 15/07/2021 at 2 m: -5.52. | Ostrander et al. (2023), Thallium isotope cycling between waters, particles, and sediment… |
| −3.62 ± 0.69 ε | −4.45 / −2.78 ε | 7 | particles of anoxic sulphidic waters Mean and standard deviation recalculated from 7 analyses, particulate Tl up to 9.4 pM on 15/07/2021, not distinct from coeval dissolved Tl; values by date and depth: 15/07/2021 at 3 m: -4.45; 15/07/2021 at 4 m: -3.78; 15/07/2021 at 5 m: -2.93; 15/07/2021 at 6 m: -2.78; 15/07/2021 at 7 m: -3.09; 15/07/2021 at 9 m: -3.95; 15/07/2021 at 11 m: -4.35. | Ostrander et al. (2023), Thallium isotope cycling between waters, particles, and sediment… |
| −3.12 ± 0.29 ε | −3.35 / −2.79 ε | 3 | authigenic fraction of sediments below oxic waters (1 to 3 m) Mean and standard deviation recalculated from 3 analyses, pyrite leach; heavier near the shore, close to overlying waters; 1 m: -2.79 (115 ng/g); 2 m: -3.23 (43 ng/g); 3 m: -3.35 (34 ng/g). | Ostrander et al. (2023), Thallium isotope cycling between waters, particles, and sediment… |
| −4.27 ± 0.41 ε | −4.84 / −3.73 ε | 8 | authigenic fraction of sediments below anoxic waters (4 to 14.25 m) Mean and standard deviation recalculated from 8 analyses, pyrite leach; minimum of -4.84 at 8.5 m (1548 ng/g Tl, the highest content), back to -3.9 and -3.7 at the two deepest points; 4 m: -3.80 (35 ng/g); 5 m: -4.43 (87 ng/g); 5.5 m: -4.56 (164 ng/g); 6.5 m: -4.38 (276 ng/g); 7 m: -4.54 (213 ng/g); 8.5 m: -4.84 (1548 ng/g); 10 m: -3.91 (122 ng/g); 14.25 m: -3.73 (215 ng/g). | Ostrander et al. (2023), Thallium isotope cycling between waters, particles, and sediment… |
| −1.93 ± 0.41 ε | −3.02 / −1.49 ε | 11 | detrital fraction of sediments (leach residue, 1 to 14.25 m) Mean and standard deviation recalculated from 11 analyses, all within average upper continental crust (-2.1 ± 1.0) except -3.02 at 8.5 m; 1 m: -1.49 (14 ng/g); 2 m: -1.61 (109 ng/g); 3 m: -1.71 (145 ng/g); 4 m: -1.80 (45 ng/g); 5 m: -1.96 (48 ng/g); 5.5 m: -1.76 (76 ng/g); 6.5 m: -2.11 (82 ng/g); 7 m: -1.81 (72 ng/g); 8.5 m: -3.02 (167 ng/g); 10 m: -1.81 (18 ng/g); 14.25 m: -2.10 (100 ng/g). | Ostrander et al. (2023), Thallium isotope cycling between waters, particles, and sediment… |
| −1.8 ± 0.4 ε | 1 | surface water of neighbouring Shivericks Pond (31 July 2021) Single analysis; ± 0.4 (2SD); 15 pM Tl; freshwater end-member of the conservative mixing model; value from the text, absent from the supplement. | Ostrander et al. (2023), Thallium isotope cycling between waters, particles, and sediment… |
Deposits of the same type
- Sargasso Sea, BATS station
- Subtropical North Atlantic, station GPrI 20 (31.67° N 64.17° W)
- Wilton natural wetland (Wisconsin) United States
- Wilton constructed wetland (Wisconsin) United States
- Atlantic, Labrador Sea, station 64PE319 8
- TAG active mound hydrothermal fluids (Mid-Atlantic Ridge)
- Atlantic, Newfoundland Basin, station 64PE319 11
- Atlantic, Irminger Basin, station 64PE319 5
Cite this page
IsoFind Atlas (2026). Siders Pond (Falmouth), isotope signatures. https://www.isofind.tech/isotopes/en/sites/etang-de-siders-falmouth/ (accessed 2026-10-15).
@misc{isofind2026siderspondfalmouthisotopesign,
title = {Siders Pond (Falmouth), isotope signatures},
author = {{IsoFind Atlas}},
year = {2026},
url = {https://www.isofind.tech/isotopes/en/sites/etang-de-siders-falmouth/},
note = {Accessed 2026-10-15}
}Updated : 2026-10-15