Piton de la Fournaise fumarolic deposits (April 2007 lava flow)
Réunion Island, Piton de la Fournaise, France
Other media
- Type
- Other medium
Fumarolic crusts sampled from 2007 to 2011 on the April 2007 flow, between 400 °C and ambient temperature: Na-K sulphates (aphthitalite), thenardite, lava-tube gypsum, Ca-Mg-Al-Fe fluorides (ralstonite) and native sulphur. Gannoun et al. (2015): rhenium highly volatile, osmium hardly; only the hottest sulphates (384-400 °C) have a mantle-like 187Os/188Os (0.1248 to 0.1287), attributed to old mantle sulphides carried into the gas. Coordinates: 300-400 °C vent of the flow (21°17′14.8″S, 55°47′34″E).
187Os/188Os isotope ratio, no unit Values of the same system
Standard : Rapport absolu, sans standard de référence
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 0.1285 ± 0.0034 | 0.1248 / 0.1337 | 6 | Na-K sulphates (aphthitalite and thenardite) Mean and standard deviation recalculated from 6 analyses, 0.1248 to 0.1337 (REU 0705 0.1273; REU 0705 (2) 0.1287; REU 0810-281 0.1248; REU 0810-281 (2) 0.1253; REU 0906-261 0.1309; REU 0911-201 0.1337). Sampled at 325-400 °C on the vent of the flow; "(2)": second analysis of the same sample. REU 0705 (400 °C) and REU 0810-281 (384 °C) stay below 0.129; the text assigns these values to "REU281 and REU261" above 380 °C, but REU 0906-261 was sampled at 345 °C. Re 24 to 79 ppb, Os 14 to 132 ppt. | Gannoun et al. (2015), Escape of unradiogenic osmium during sub-aerial lava degassing: ev… |
| 0.1327 ± 0.0013 | 0.1316 / 0.1341 | 3 | thenardite Mean and standard deviation recalculated from 3 analyses, 0.1316 to 0.1341 (REU 0808-292 0.1316; REU 091204-11 0.1341; SR2 0.1323). REU 0808-292 at 100 °C, REU 091204-11 cold (December 2009 crack, 21°14′45.3″S, 55°43′15.6″E), SR2 from 1977. | Gannoun et al. (2015), Escape of unradiogenic osmium during sub-aerial lava degassing: ev… |
| 0.1347 | 1 | native sulphur Single analysis (SR1). Sample SR1, with no date or location in Table 1. | Gannoun et al. (2015), Escape of unradiogenic osmium during sub-aerial lava degassing: ev… | |
| 0.1315 ± 0.0001 | 0.1314 / 0.1316 | 5 | Ca-Mg-Al-Fe fluorides (ralstonite) Mean and standard deviation recalculated from 5 analyses, 0.1314 to 0.1316 (REU 0808-293 0.1315; REU 0808-294 JV 0.1314; REU 0808-294 O 0.1316; REU 0808-295J 0.1315; REU 0808-295 B 0.1316). Low-temperature deposits (100 °C) on the flow surface, the richest in osmium (13 to 77 ppb); ratio identical to that of the lavas. | Gannoun et al. (2015), Escape of unradiogenic osmium during sub-aerial lava degassing: ev… |
| 0.131 ± 0.0009 | 0.1299 / 0.1321 | 4 | lava-tube gypsum Mean and standard deviation recalculated from 4 analyses, 0.1299 to 0.1321 (AF 1105 G (a) 0.1314; AF 1105 G (d) 0.1321; AF 1105W (a) 0.1307; AF 1105 G (c) 0.1299). Tube formed within the April 2007 flow, sampled cold in May 2011. | Gannoun et al. (2015), Escape of unradiogenic osmium during sub-aerial lava degassing: ev… |
| 0.1332 ± 0.0019 | 0.1313 / 0.1357 | 5 | basalt (2007 and 2009 lavas) Mean and standard deviation recalculated from 5 analyses, 0.1313 to 0.1357 (REU 070402 0.1313; REU 070404 0.1320; REU 070405 0.1357; REU 070408 0.1322; REU 0912-043 0.1346). Within the range of the 1931-2006 historical lavas (0.1311 to 0.1374, Schiano et al., 2012), more radiogenic than the primitive upper mantle (0.1296). | Gannoun et al. (2015), Escape of unradiogenic osmium during sub-aerial lava degassing: ev… |
Deposits of the same type
- Hydrogenetic Fe-Mn deposit (crust), Indian Ocean (Antipode, 109D-C)
- South Atlantic, station 8 of the GEOTRACES 40° S cruise
- Hydrogenetic Fe-Mn deposit (nodule), Southern Ocean (TBD 463, 6854-6)
- Hydrogenetic Fe-Mn deposit (crust), Indian Ocean (DODO, 232D)
- South Atlantic, station 3 of the GEOTRACES 40° S cruise
- Atlantic, Cape Basin, station ANT XXIII/1 69/26
- South Atlantic, station 11 of the GEOTRACES 40° S cruise
- Subantarctic South Atlantic, Meteor Rise (TSO-5)
Cite this page
IsoFind Atlas (2026). Piton de la Fournaise fumarolic deposits (April 2007 lava flow), isotope signatures. https://www.isofind.tech/isotopes/en/sites/depots-fumeroliens-du-piton-de-la-fournaise-coulee-d-avril-2007/ (accessed 2026-10-20).
@misc{isofind2026pitondelafournaisefumarolicde,
title = {Piton de la Fournaise fumarolic deposits (April 2007 lava flow), isotope signatures},
author = {{IsoFind Atlas}},
year = {2026},
url = {https://www.isofind.tech/isotopes/en/sites/depots-fumeroliens-du-piton-de-la-fournaise-coulee-d-avril-2007/},
note = {Accessed 2026-10-20}
}Updated : 2026-10-20