Epithermal gold deposits are known for shallow-depth hydrothermal activity, often depositing valuable metals like gold and silver into open spaces such as faults and fractures. The term "epithermal" was first used by Waldemar Lindgren in 1894 in "The Gold Quartz Veins of Nevada City and Grass Valley Districts, California." With rising gold prices and advancing technology, the allure of these deposits has increased. As a result of heightened interest, many weathered and exposed deposits have been discovered. Considering the risk involved in exploring undiscovered or partially eroded ancient hydrothermal systems, evaluating all clues becomes crucial. Fieldwork and drilling reveal valuable clues through observed lithological elements. In this piece, we examine the most crucial of the indicative criteria for hydrothermal deposits: the alteration model. We delve into alteration types such as argillic and propylitic, discussing field recognition.
