Research Information System
GEOTHERMAL ENERGY, vol.13, no.37, pp.1-28, 2025 (SCI-Expanded)
The Kızıldere Geothermal Field (KGF), situated at the eastern margin of
the Büyük Menderes Graben, is the most productive high-enthalpy
geothermal system in Türkiye, with reservoir temperatures exceeding
240 °C and an installed capacity of over 360 MW. Its heat is derived
from crustal thinning, shallow Curie depths, and lithospheric extension
related to the post‑Oligocene evolution of the Menderes Metamorphic Core
Complex. This extensional tectonic setting produces high regional heat
flow (up to 120 mW/m2) and steep geothermal gradients that
favour deep fluid circulation. To resolve the structural and
hydrogeological controls on this system, we combined detailed field
mapping, paleostress and kinematic analyses, 76 boreholes (530–3882 m),
and 3D geological and thermal modelling. The results reveal that fault
architecture is the principal control on fluid flow and geothermal
productivity. E–W‑striking high‑angle normal faults act as major
recharge pathways for meteoric waters, whereas NE‑trending sub‑vertical
transfer faults, particularly the Gebeler Fault, form vertical conduits
that enable the rapid ascent of thermal fluids. Intersections of these
faults create favourable zones, where fractured marbles, quartzites, and
carbonate‑rich basin‑fill units function as reservoirs, sealed by
gneisses, schists, and clay‑rich Miocene deposits. This study
demonstrates that the interplay between fault geometry and lithology
governs the exceptional productivity of the KGF. The insights gained
provide a predictive framework for targeting high‑permeability zones,
extensional geothermal systems in Western Anatolia, and similar tectonic
settings worldwide.