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Geology
The Galapagos Islands are a series of gigantic volcanic peaks, created by the movement of the Nazca plate towards the South American plate at a rate about seven cm a year. The islands are composed of almost exclusively metaphoric basalt, giving the islands their dark gray color. They do, however, differ from almost all volcanic regions in the world, as the Galapagos Islands do not lie on the border of two tectonic plates.
The Galapagos Islands contain the most active volcanoes in the world and eruptions have taken place on Fernandina, Isabela, Pinta, Marchena, Santiago and Floreana. Now the most active volcanoes are found on Fernandina, Isabela, Pinta and Marchena, and volcanic activity may be seen occasionally on each of these islands.
The most plausible reason for this geographical phenomenon is known as the Hot Spot Theory. This theory states that the volcanoes are created as a result of magma hot spots where magma at extremely high temperatures bubbles to the surface to form a volcano. The theory demonstrates why the most easterly islands show the greatest effects of erosion and are the oldest. San Cristobal is estimated between 2.3 and 3.6 million years old.
Evidence for this activity can be seen all over the Galapagos as the majority of the Galapagos’ landmass consists of lava flows.
Due to the nature of their origins, it is therefore common to be able to see volcanic cones of different shapes and sizes, ranging less then one meter high to the larger spatter cones found on Bartolome. More extreme evidence of the hot spot theory is seen at Urbina Bay on Isabela. Here tectonic activity caused an uplift of landmass in 1954. The islands of Plazas and Baltra are the project of this uplift, where a stretch of reef was raised up by for meters as a result of the magma flowing beneath.
Thirteen large islands, over forty tiny islands and many rocks form the Galapagos archipelago which lies in the Pacific Ocean about 960 km west from Ecuador. Galapagos is a province of the Republic of Ecuador, although only four of the islands are inhabited, with a total population of around 18,000 people. The capital is Puerto Baquerizo Moreno on San Cristobal Island but the biggest city is on Santa Cruz: Puerto Ayora.
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About Galapagos 
