Before it became the world’s largest geothermal power-producing site, The Geysers was known as the “Gates to Hades,” drawing visitors with its healing waters, steam vents, and wild legends.
Normal Fault
High angle fault that results from extensional stress and forms a steeply dipping planar structure. Slip movement during an earthquake is vertical and down dip. The down-dropped block is called the hanging wall and the uplifted block is called the footwall.
Geothermal Glossary
Word of the Week – Cement Bond Log
Cement Bond Log A geophysical well log that is obtained using a sonic-type tool on a wireline. The result helps to confirm the integrity of the hardened cement that was injected to form a bond between well casing and the adjacent rock formation.
Word of the Week – Chemical Geothermometer
Chemical Geothermometer A temperature that is calculated based on the chemical composition of a hydrothermal fluid and involves knowing a ratio (e.g., Na/K) or knowing the absolute concentration of a species (e.g., SiO2). Temperature is computed using a simple...
Word of the Week – Chlorite
Chlorite A micaceous mineral that is commonly green-colored, composed of iron and/or magnesium, and forms due to hydrothermal alteration of amphiboles, pyroxenes, and feldspars.