Resumen: Spain is one of the main gypsum producers in the world. Spanish gypsum reserves are large and a good
knowledge of the location of the ore reserves permits to establish better exploitation strategies. Plotting
the Spanish major gypsum outcrops, using a GIS base, helps to classify them by age, establish the main depositional
and determine the factors controlling their origin.
Evaporitic deposits from Cambrian to Quaternary are preserved throughout Spain. The evaporites are formed
by chemical precipitation of natural brines, either of marine or continental origin. The oldest evaporite vestiges
in the Spanish geological record have been described in carbonate materials, as gypsum and anhydrite
pseudomorphs, in Cambrian deposits of the Cantabroâ€“Iberian basin (northern Spain). The first properly identified
evaporite formation in Spain is located in the Triassic deposits that characterize central and northern
Europe. In Spain, evaporites of this age appear well represented in 4394.5 km2 of outcrop area in the eastern
part of the Iberian Peninsula. The Lower Jurassic (covering 1068 km2 of outcrop area) and the Cretaceous
(covering 706.9 km2 of outcrop area) are periods of intense evaporitic sedimentation, and outcrops appear
concentrated towards central and eastern parts of the Peninsula. More recently, in the Cenozoic, numerous
continental and marine basins resulted from the tectonic activity produced by the Alpine Orogeny. Here, a
combination of different factors produced thick and wide evaporite accumulations (outcrop surface is
13592.7 km2). In the Quaternary, evaporitic conditions are common in Spain, including various saline lakes
(covering 1092.1 km2 of outcrop area) mainly in the Ebro basin and La Mancha zone. In addition, there are
many artificial marine salinas.
The evaporitic conditions in a basin strongly depend on factors such as climate, tectonics and brine composition.
A study of the spatial distribution and age of the gypsum-bearing units in Spain suggests a wide variation
in factors controlling the origin of gypsum deposits. The Spanish evaporite precipitation from Permian
to Jurassic times was controlled by global conditions such as climate. They were formed during a global
warming period. On the other hand, evaporites formed from late Cretaceous to Neogene were more
influenced by regional factors that were related to the tectonic activity produced by the Alpine Orogeny. At
present evaporite precipitation occurs due to the endorheic character of lakes in some parts of Spain.
Resumen: The fluorite deposits of Asturias (northern Iberian Peninsula) are hosted by rocks of Permo-Triassic and Palaeozoic
age. Fluid inclusions in ore and gangue minerals show homogenization temperatures from 80 to 170C and the
presence of two types of fluids: an H2Oâ€“NaCl low-salinity fluid (