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Earth of fire

Actualité volcanique, Article de fond sur étude de volcan, tectonique, récits et photos de voyage

Santo Antão, the second largest island of the archipelago with 779 km², is a land of contrasts : she alternates mineral of its peaks and green valleys plunging deep into the ocean, she alternates climates, the south is dry and arid while the north is green and covered with subtropical vegetation.
 Santo Antao - 6 - CHB
                       Santo Antao - photo © 2013 Carole and Frederic Hardy
Santo Antao - 2 - CHB
                                                    photo © 2013 Carole and Frederic Hardy

Santo Antao - 11 - CHB

        Santo Antão - varied landscapes of the island - photo © 2013 Carole and Frederic Hardy

Santo Antao - 5 - CHBSanto Antão - cliffs and volcanic sand - erosion by the ocean - photo © 2013 Carole and Frederic Hardy

Discovered on January 17, 1462 , it will be populated by 1548 ... which has not prevented the Cape Verdeans to sculpt the mountain, to cultivate on countless terraces, with a floor made ​​of black lava and lighter pozzolan , coffee, sugar cane, corn or cassava .
This favorable climate has also allowed the introduction of palms, mango trees and carob, lemon, papaya and orange. The eucalyptus rubs lavender, lotus and the dragon tree .
 
Santo Antao - 9 - CHB
   Santo Antão - a stone lace rubs cultivated terraces - photo © 2013 Carole and Frederic Hardy

To survey these cultures that draw a mosaic under mineral lace, improbable stony stairs and spiral paths cross the vertiginous walls .
 
Santo Antao - 4 - Entre Ponta Do Sol et Cruzinha da Garça                                        photo © 2013 Carole and Frederic Hardy
Santo Antao - 12 - Vale do Paul CHB                                           photo © 2013 Carole and Frederic Hardy
Santo Antao - 14 - CHB                              photo © 2013 Carole and Frederic Hardy
Santo Antao - 13 - CHB
Santo Antão - the stone paths traverse the side of thecliffs - photo © 2013 Carole and Frederic Hardy

The volcanic history of Santo Antão include magmas of basanite - phonolite series between 7.5 Ma and 300,000 years, and magmas of nephelinite - phonolite series between 700,000 and 100,000 years.

These differences are explained by the rise of a non-homogeneous mantle plume. The inter-island variation reflect a lateral zonation in the plume .

Santa antoa - relief - emeraldinsightRelief of Santo Antão - doc . emeraldinsight
To put in correspondence with the geologic map below

 



 

 

 

 

 
Santa Antao - carte géol. journ of petrology
Geological map of Santo Antao - Holm et al. / Journal of Petrology / ref. in sources.

 

 
 

 

 

 

 

 

 

 

 

 

 

 

Santo Antao - 3 - CHBSanto Antão - a volcanic dyke, accessible by vertiginous paths overlooking the sea - photo © 2013 Carole and Frederic Hardy

Sources:
- Journal of Petrology - Sampling the Cape Verde mantle plume : evolution of melt composition on Santo Antao , Cape Verde islands . - P.M. by Holm et al.
- Springer - the Cape Verde archipelago .

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