IDDP—The chemistry of the IDDP-01 well fluids in relation to the geochemistry of the Krafla geothermal system

The Leirbotnar field, where IDDP-01 is situated consists of an upper liquid dominated zone to 1000–1400 m depth, 190–220 °C, sulphate major anion, and a lower two phase zone, 300 °C chloride main anion. The IDDP-01 fluid is dry steam, local origin, pH 3. The major anion is chloride (20–166 mg/kg), probably of magmatic origin. The major metallic cations, Fe (5–100 mg/kg), Cr (0–6 mg/kg), Ni (0–5 mg/kg) and Mn (0.1–0.8 mg/kg) seem to be derived from the well casing and sampling equipment. The gas content is low (about 0.1%) and the gas is apparently not directly emitted from magma.