McCleskey, R. BlaineÌý1Ìý;ÌýNordstrom, D. KirkÌý2Ìý;ÌýBall, James W.Ìý3
1ÌýU.S. Geological Survey / ÀÖ²¥´«Ã½
2ÌýU.S. Geological Survey
3ÌýU.S. Geological Survey
The Gibbon R. flows by Norris Geyser Basin, Gibbon Geyser Basin, and Chocolate Pots before it joins with the Firehole R. to form the Madison R. The purpose of this study was to quantify thermal and non-thermal chemical inputs and attenuation in the Gibbon R. Synoptic water samples and discharge measurements were obtained from the Gibbon R. and its major tributaries under low-flow conditions. The pH of the Gibbon R. ranged from 6.9 to 7.2, the specific conductance ranged from 120 to 430 μS/cm, and the discharge ranged from 1.3 to 2.5 m3/s. Tantalus Cr., the largest drainage in Norris Geyser Basin, contributes the largest single load of Al, As, B, Cl, Fe, Li, Na, SiO2Ìýand SO4Ìýto the Gibbon R. No solutes appear to be attenuated in the Gibbon R. However, Fe is oxidized but does not sorb or deposit and the dissolved Hg load decreases where the total Fe load increases suggesting Hg sorption onto iron hydroxide particles. All solute loads near Norris Geyser Basin are accounted for by inflows except Hg, whose source appears to be from a nearby wetland west of Norris Geyser Basin.