Merces Quarry laterite profile (Goa)
Goa, Panjim-Merces plateaux (Konkan-Kanara lowlands), India
Soils
- Type
- Soil
35 m weathering profile formed in the Miocene (about 20 to 10 Ma) on a Palaeoproterozoic metagreywacke of the Goa Group (Sanvordem Formation, Dharwar Supergroup). 37 to 652 ng/g Tl, net Tl loss in the profile. ε205Tl close to the protolith (-2.3) in the weathered greywacke, then heavier upward, with a peak of +3.5 in the massive laterite at 7.5 m, at the inferred palaeo-water table; profile mean close to common igneous rocks (Howarth et al., 2018). Published coordinates (15° 28.46' N, 73° 52.33' E).
ε205Tl in ε units (parts per 10,000) Values of the same system
Standard : NIST SRM 997
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| −1.93 ± 0.46 ε | −2.4 / −1.3 ε | 4 | weathered greywacke (30 to 15 m) Mean and standard deviation recalculated from 4 analyses, SQ3 to SQ6, 231 to 700 ng/g Tl; close to the protolith (-2.3); ± 0.5 to 0.6 ε (2 SD) on each value. | Howarth et al. (2018), Thallium concentration and thallium isotope composition of laterit… |
| −0.62 ± 0.69 ε | −1.2 / 0.3 ε | 4 | laterite base and nodular to semi-indurated laterite (14 to 8.5 m) Mean and standard deviation recalculated from 4 analyses, SQ7 to SQ10, 40 to 148 ng/g Tl; ± 0.4 to 0.5 ε (2 SD) on each value. | Howarth et al. (2018), Thallium concentration and thallium isotope composition of laterit… |
| 3.5 ± 0.6 ε | 1 | massive laterite at 7.5 m (inferred palaeo-water table) Single analysis; SQ11, 456 to 544 ng/g Tl, concentration peak; heavy excursion ascribed to redox changes and neoformed oxides. | Howarth et al. (2018), Thallium concentration and thallium isotope composition of laterit… | |
| −1 ε | −1 / −1 ε | 2 | indurated laterite cap (3.5 to 2.5 m) Mean and standard deviation recalculated from 2 analyses, SQ12 and SQ13, 103 to 135 ng/g Tl; ± 0.4 ε (2 SD) on each value. | Howarth et al. (2018), Thallium concentration and thallium isotope composition of laterit… |
Deposits of the same type
- Bidar laterite profile (Deccan basalts) India
- Agricultural soils south-west of the Jinding mine China
- Agricultural soils north-east of the Jinding mine China
- Regional background soils north-east of Jinding China
- Soils and sediments of the artisanal zinc smelting region (Guizhou) China
- Hezhang artisanal zinc smelting area soils China
- Qingzhen power plant soils China
- Huaxi control site soils China
Cite this page
IsoFind Atlas (2026). Merces Quarry laterite profile (Goa), isotope signatures. https://www.isofind.tech/isotopes/en/sites/profil-lateritique-de-la-carriere-de-merces-goa/ (accessed 2026-10-15).
@misc{isofind2026mercesquarrylateriteprofilego,
title = {Merces Quarry laterite profile (Goa), isotope signatures},
author = {{IsoFind Atlas}},
year = {2026},
url = {https://www.isofind.tech/isotopes/en/sites/profil-lateritique-de-la-carriere-de-merces-goa/},
note = {Accessed 2026-10-15}
}Updated : 2026-10-15