Geossítios
GEO

Vale do rio Guadiana – corte geológico da Serra Branca

justificação do valor científico

The volcanic-sedimentary complex of the Iberian Pyrite Belt includes products of felsic effusive and explosive eruptions, and resedimented volcaniclastic debris, interbedded with non-volcanic sedimentary facies that are largely dominant. This contrasts with the volcanic-dominated host successions of most VHMS provinces worldwide. At the Guadiana river valley - Serra Branca area a well exposed continuous sequence of volcanic and volcaniclastic rocks provides recognition of the local volcanic facies architecture in such a way that renders possible to interpret and explain in simple terms the styles of volcanic activity and sedimentation there recorded, and the temporal and genetic relation of the volcanic events to the formation of the massive sulfide mineralization. At Serra Branca, a lava-cryptodome-pumice cone volcanic centre distributed over an area of about 8 km in diameter consists of at least fourteen felsic lavas or domes and cryptodomes, intercalated with pyroclastic units, and comprises aprons of resedimented hyaloclastite or, farther from the source vent, crystal-rich sandstone facies intercalated with mudstone. Paleogeographical reconstitutions are also possible at Serra Branca. For instance, the algae-bearing (dasycladales fragments) volcaniclastic units, occurring in the intermediate and upper parts of the stratigraphy, suggests proximity to a palaeo-shoreline (Rosa et al., in press).
Geosite of Iberian dimension in the context of the IPB, with excellent access and visiting conditions.

Outros valores e sua justificação

Serra Branca is located very near Mértola, a historical village with very interesting Moorish architecture and monuments.

Observações

Coordenadas em actualização.