Candidatura Reserva da Biosfera - Santana Madeira Biosfera

Figure 41. Volcanic landscape in the Central Mountainous Massif
According Schmincke (1982), the island of Madeira is an oceanic mountain with a
volume of about 9.2x103 km 3 , including emerged and immersed parts, of which only
0.4x103 Km 3 correspond to the submerged part, this constituting about 4.2 % of total
volume of the island. Lithologically the submerged part of this volcanic mountain consists
essentially on quartz poor melanocratic effusive rocks of aphanitic texture or pyroclastic
type rocks resulting from explosive volcanic activity. Most lava spilling flows is composed
by rocks of the basaltic series, comprising basalts, basanites, trachy-basalts. The
lithological wealth is magnified by rock types present in discordant geological forms such
as veins and dykes, where melanocratic, mesocratic and leucocratic microfaneritic or
aphanitic rocks can be found, such as trachyandesite, trachytes, tephrite and other rarer
types of porphyritic texture with olivine, augite, hornblende and andesine-labradorite
phenocrysts as benmoreits, hawaiites and mugearits. Regarding the pyroclastic rock
types, in the more consolidated pyroclastic deposits tuffs, lapilli tuffs, pyroclastic breccias
and agglomerates can be found, while in areas where recent Strombolian volcanic
phenomena occurred, scarcely consolidated clastic lava deposits dominate, which
depending on their size include ash, lapilli, locally known as Areão and volcanic bombs
and blocks.
The geological importance of the municipality of Santana, is expressed by the
diversity of eruptive volcanic episodes occurring over approximately 17 m.y. from the
Application of Santana, Madeira to Biosphere Reserve – UNESCO - MAB 73