The origins of the Galapagos Islands are best understood in a geological context. The theory of plate tectonics
that underpins modern geology offers a neat hypothesis for the presence of the Galapagos. Unlike continents,
which are large masses of granitic rock surrounded by basaltic oceanic plates, the Galapagos Islands, which is
an island chain in the middle of the ocean are comprised mostly of basalt, is the result of eruptions from
oceanic plates. To explain this, geologists devised the "hotspot" model. This is based on the idea that
a plume of hot material is rising from deep in the earth's mantle and melts the overlying oceanic plate.
This material rises to the surface and solidifies into the islands we see today. There is good circumstantial
evidence for this idea, but the origin of the underlying mechanism within the mantle remains mysterious.
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"...we are led to believe that within a period, geologically recent,
the unbroken ocean was here spread out."
Charles Darwin The Voyage of the Beagle 1854