Factors governing subaqueous siliceous sinter precipitation in hot springs: examples from Yellowstone National Park, USA
Article first published online: 11 DEC 2002
Volume 49, Issue 6, pages 1253–1267, December 2002
How to Cite
Guidry, S. A. and Chafetz, H. S. (2002), Factors governing subaqueous siliceous sinter precipitation in hot springs: examples from Yellowstone National Park, USA. Sedimentology, 49: 1253–1267. doi: 10.1046/j.1365-3091.2002.00494.x
- Issue published online: 11 DEC 2002
- Article first published online: 11 DEC 2002
- Manuscript received 8 August 2001; revision accepted 18 June 2002.
- hot springs;
- siliceous sinter;
Abstract Siliceous sinter precipitation within hot spring systems has been attributed to a variety of mechanisms: evaporative concentration, cooling, changes in pH and cation effects. Repetitive in situ (T, pH, alkalinity, etc.) and laboratory (major, minor and trace elemental, stable isotopic) analyses of the waters plus observations of silica precipitation on natural (e.g. twigs, pine cones) as well as artificial substrates (glass slides and copper plates) in the waters substantiate that subaqueous precipitation is occurring throughout the vent to distal end of flow in both Cistern Spring (Norris Geyser Basin) and Deerbone Spring (Lower Geyser Basin), Yellowstone National Park, Wyoming, USA. Quartz and sodium–potassium geothermometers indicate that Cistern Spring is fed by a subsurface reservoir that is between 232 and 272 °C. Calculated reservoir temperatures are significantly lower at Deerbone Spring (182–197 °C). Based on a suite of measured and theoretical saturation indices, downflow changes in the system resulting from evaporative concentration (e.g. Cl increases 10%), changes in pH (e.g. 5·6–7·1) and cation effects (Al and Fe) are of negligible importance in the subaqueous precipitation of hot spring opal-A. Similarly, at the macroenvironmental scale, potential biotic effects on opal-A precipitation appear to be minimal. Modelling of the two active siliceous sinter precipitating systems indicates that cooling (e.g. 80–17 °C) is the predominant process governing subaqueous mineral precipitation.