Isotopic Analysis At Valles Caldera - Redondo Geothermal Area (Goff, Et Al., 1982)

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Exploration Activity: Isotopic Analysis At Valles Caldera - Redondo Geothermal Area (Goff, Et Al., 1982)

Exploration Activity Details
Location Valles Caldera - Redondo Geothermal Area
Exploration Technique Isotopic Analysis- Fluid
Activity Date - 1982
Usefulness useful
DOE-funding Unknown

Field, chemical, and isotopic data for 95 thermal and nonthermal waters in and around the Valles Caldera were collected to help interpret the geothermal potential of the Jemez Mountains region and to provide background data for investigating problems in hydrology, structural geology, hydrothermal alterations, and hydrothermal solution chemistry. Temperature and pH data were measured in the field using mercury thermometers and either a pH meter or sensitive limited range pH test papers (Colorfast Indicator Strips nos. 9581, 9582, and 9583). Flow rates of wells were measured using wellhead gauges where possible; flow rates of springs were estimated visually. Waters sampled for chemical analysis were stored in brimful polyethylene bottles with Polyseal caps following filtration from a large syringe attached to a filter holder containing 0.8 um filter paper. Three duplicates were taken at each sample point and were treated in the field in preparation for chemical analyses. These included: 1) a 500 mL bottle of filtered unacidified water for anions, 2) a 250 mL bottle of filtered water acidified dropwise with dilute HCl to pH <2 for cations, and 3) a 125 mL bottle containing 10 mL of filtered water (sample) diluted with 90 mL of deionized water for silica. Samples used for measurement of Al were collected and analyzed according to a procedure modified from Barnes (1975), and is described in the study. Samples were also collected from select sample points for isotopic analysis by filling 125 mL glass bottles full of raw water and sealing with a Polyseal cap. The sample set included 22 samples from the Jemez Springs geothermal area; 15 samples from the Sulphur Springs geothermal area; and 13 isolated samples from what is now known as the Redondo geothermal area. Major element lab analyses were performed by a colorimetric method using a yellow molybdate complex for SiO2; by atomic absorption spectroscopy (AAS?) for Fe, Mn, Ca, Mg, Na, K, and Li; by sulfuric acid titration for HCO3; by ion chromatography for SO4 and Cl; by either selective ion electrode or iono chromatography for F; by colorimetry using azomethine-H for B; and by atomic absorption spectroscopy (AAS?) using either a graphite furnace or flame excitation for Ag, Ba, Cd, Cr, Cu, Mo, Ni, Pb, Sr, and Zn. Analysis of the D and 18O isotope content of select samples were performed in accordance with standard methods.


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