Jasiiraduhu waxay ku yaalliin Saxan Nazca (saxan tektonik ah), kaas oo u dhaqaaqaya bari / koonfur-bari, oo hoos u dhacaya saxanka Koonfurta Ameerika qiyaastii 2.5 inches (6.4 cm) sanadkiiba. Waxay sidoo kale ku taal dusha sare ee Galápagos hotspot, oo ah meel ay lafaha dhulka ka soo dhalaalayso xagga hoose oo ay ka soo baxdo qulqulka mantle, oo abuureysa volcanoes. Jasiiradihii ugu horreeyay ee halkan ka sameysmay ugu yaraan 8 milyan oo laga yaabee ilaa 90 milyan oo sano ka hor. In kasta oo jasiiradaha waaweyn ay badda hoosteeda ku baaba'een markii ay ka fogaadeen qulqulka mantle, jasiiradaha ugu da'da yar, Isabela iyo Fernandina, ayaa weli si firfircoon u sameysanaya.
18 jasiiradood oo waaweyn