Preliminary Conceptual Model of the Paipa Geotermal System, Colombia

Abstract

Based on the integration of surface studies a geothermal system located in a small caldera shaped by the Paipa volcano after its first eruptive epoch, is proposed. The characteristics of this system include a magmatic heat source with age around 2.5 – 2.1 million years, a deep fractured reservoir, surrounding the extensional basement falls (Paipa-Iza, Cerro Plateado), which additionally are assumed as the possible conduits for the ascent of magma. Although the hydrothermal alteration shows evidence of high temperature fluids (320°C), the current reservoir temperature is unknown as the fluids suffer a “masking” effect by the contribution of highly mineralized surface water and an organic source which affect the geochemical indicators. That is, the chemistry and isotopic composition of the discharged fluids in hot springs are not representative of the reservoir fluids. Secondary reservoirs hosted in the strata of high primary permeability from the sedimentary sequence are proposed. Their lateral extension would allow the geothermal water to flow towards the discharge zone, located northward from the volcanic caldera, which is structurally controlled by crossing fault zones and extensional zones related to the transverse blocks rotation.