Table 2 Mineral associations in soils and parent materials within zones of discharge of steam-heated acid-sulfate waters.
Territory | Parent materials | Temperature, °C | Sampling depth, cm | Minerals | References | ||
|---|---|---|---|---|---|---|---|
Rock-forming | Accessory and markers | ||||||
Russia, Kamchatka Peninsula | Valley of Geysers | Rhyolite-dacites or andesites | 30–50 | 0–40 and 220–280 | Smectite, feldspars, quartz | Plagioclases, anatase, zeolites, kaolinite, cristobalite | This study |
50–80 | 0–25 | Kaolinite, anatase, zeolites | Plagioclases, quartz, feldspars, smectite | ||||
80–100 | 0–8 | Kaolinite | Anatase, zeolites, plagioclases, hematite, quartz, cristobalite, feldspars, pyrite, smectite, boehmite | ||||
100 | 0–10 | Kaolinite, quartz | Halloysite, non-ordered smectite (montmorillonite), clinoptilolite | ||||
East Pauzhetka thermal field | Andesitic lavas | 20–30 | 0–70 | Kaolinite | Pyrite, α-quartz, alunite, jarosite, goethite | ||
|  |  | 35–70 | 70–250 | Kaolinite | Pyrite, α-quartz, opal, feldspars, marcasite, alunite, jarosite, goethite |  | |
|  |  | 70–80 | 250–290 | Kaolinite, smectite | – |  | |
|  |  | 80–95 | 300–350 | Smectite | α-Quartz, opal, feldspars (albite), pyrite and other sulfides, magnesio-calcite |  | |
|  |  | 95–100 | 350–400 | Smectite, opal, quartz, magnesio-calcite | Pyrite |  | |
Upper Pauzhetka thermal field | Andesites |  < 98 | 0–30 | Kaolinite, limonite | Dioctahedral smectite, pyrite, quartz, heulandite, plagioclases, elemental sulfur, jarosite | ||
|  |  |  | 5–50 | ‘Blue clays’: pyrite, silica (opal, chalcedony, quartz) | Jarosite, (hydro)goethite, hematite |  | |
|  |  |  | 30 (50)–180 (200) | Montmorillonite | Pyrite, hematite, (hydro)goethite, feldspars, silica (opal, chalcedony, quartz), illite–smectite, chlorite-smectite, magnetite, titanomagnetite |  | |
South Kambalnoe Dalnee thermal area | Andesites | 80–95 | 25–162 | Smectite** | Kaolinite, anatase, gypsum, opal, hematite, pyrite, gypsum | ||
Tuffites |  | 150–310 | Kaolinite | Smectite, quartz, cristobalite, and opal | |||
| Â | Â | 100 | Topsoil | Opal, quartz, kaolinite | Alunite, sulfur, goethite | ||
Na | Andesites and basalts | 40 | 0–200 | Opal | Alunite, sulfur, gypsum, pyrite, alum (Al hydrated sulfate), (hydro)goethite | ||
|  |  | 20–100 | 0–400 | Kaolinite | Alunite, gypsum, opal, mordenite, pyrite, (hydro)goethite |  | |
Russia, Kuril Islands | North Paramushir hydrothermal magmatic system | Calcareous tuffite and tuffs | 100* | Na | Opal, cristobalite | Jarosite, hematite, Fe hydroxides | |
| Â | Â | Â | Â | Silica, smectite, chlorite (up to 25%) | Jarosite, gypsum | Â | |
|  |  |  |  | Quartz, alunite | – |  | |
Saint Lucia, Soufriere Volcanic Centre | Sulfur Springs | Dacites | 41 – 97 | Surface | Kaolinite, quartz | Feldspars, cristobalite, (natro)alunite, jarosite | |
USA, California | Little Hot Springs Valley (Lassen Volcanic National Park) | Travertines | Na | Surface | *Kaolinite, montmorillonite, alunite, natroalunite, opal, cristobalite | *Anatase, goethite, jarosite, hematite, Fe-sulfate minerals, native sulfur | |
Landslides and colluvial sediments derived primarily from andesitic lavas | 20 – 100 | 0–100 | Kaolinite, smectite | Alunite | |||
Mexico | Los Azufres geothermal field | Pleistocene rhyolite | Na | Near-surface | Cristobalite, tridymite, opal, quartz, kaolinite | – | |
Iceland | Thermal fields Theistareykir and Namafjall | Basaltic hyaloclastites |  > 20 | Surface | *Pyrite, smectite, kaolinite | *Anatase, zeolites, alugene | |
