ESPINO, Fuente del

INFORMACIÓN APORTADA POR EL GEOPARQUE DE LAS SIERRAS SUBBÉTICAS:

Hawthorn Spring

Sierras Subbéticas is composed of a sequence of sedimentary rocks primarily from the Mesozoic, which were deformed during the Alpine Orogeny in the Cenozoic. This phase of deformation resulted in the uplift of extensive mountain ranges across Europe and Asia, and here it led to the advancement of various thrust systems that eventually stacked the entire sequence. The current configuration of Sierras Subbéticas is, therefore, a repeated succession of permeable materials (limestone and dolomite) and impermeable (marl, marl-limestone, and gypsum-bearing clay) ones. This explains why springs can be found at high altitudes and far from the edge of the mountain massif, such as the Hawthorn Spring (at 1.070 metres high).
Rainwater falling on the limestone and dolomite of the nearby hills, Abuchite and El Charcón, does not infiltrate to the lower water table. Instead, it encounters Paleogene marls and marl-limestones as well as Triassic gypsum-rich clays, which promote the emergence of water sources at the base of these formations.
The small size of the aquifers suspended at such high altitudes explains the generally low flow rates of these springs. While the Hawthorn Spring easily overflows with water during rainy periods, it typically has a flow rate of around 2 litres per second, and it is rare for it to dry up during the summer.
To ensure livestock could make the most of this modest flow, the storage capacity of the spring was increased through successive construction phases until it reached its current size and distinctive L-shape.