La Vega de San Mateo is a municipality on the island of Gran Canaria. It is located in the central part of the island, bordering the municipalities of Valleseco and Teror to the north, Santa Brígida and Valsequillo to the east, San Bartolomé de Tirajana to the south, and Tejeda to the west.
It covers an area of 37.89 km² (47% of which belongs to the Protected Area of the Cumbres de las Cumbres), extending from the Medianías to the summit area, starting at an altitude of 800 meters, up to the Massif Central, where the island's highest peaks are found: Pico de Las Nieves (1,961 m), Los Pechos (1,951 m), and Roque Saucillo (1,890 m).
This delimits an area where geological materials corresponding to the second eruptive cycle, or Roque Nublo, appear. Indeed, some sectors contain the volcanic agglomerate or breccia characteristic of this eruptive phase.
Acid products are also present, which can form phonolitic flows, giving rise to domes or pitons, as in the case of Roque Saucillo, Cruz Santa, etc. However, these are basaltic materials (series I and II), already from the next cycle. Volcanic, post-Roque Nublo, are the most widely represented. Finally, there are some recent volcanic edifices, typical of the last phase of Gran Canaria's formation (Series IV). This is the case of Calderilla, a volcanic depression considered a sea due to its origin and appearance, typical of a phreotomagmatic eruption (a mixture of magma water).
The upper sector of the municipality is integrated into the Gran Canaria central massif, uniting the main heights of the island and partly forming the buttress of the outer walls of the Caldera de Tejeda.
The ridge area constitutes the wide headwaters of the Guiniguada basin, formed by various ravines, most notably La Mina, La Higuera, and their corresponding tributaries. These channels mark strong incisions in the relief, and the few flat areas and terraced slopes are used for growing crops. Volcanic eruptions have occasionally led to the accumulation of alluvium, closing the course of ravines, or softening the relief, as in Vega de San Mateo itself, creating, in both cases, optimal conditions for agricultural use.
