CONCLUSIONS

Conclusions are as follows:

1. Three subsequent spreading systems formed the oceanic crust of the Cocos and Nazca plates: CNS-1, ~23-19.5 Ma; CNS-2, 19.5-14.7 Ma; and CNS-3, 14.7 Ma-present;

2. Hotspot traces overprint oceanic crust formed at the subsequent spreading centers of the Cocos-Nazca spreading system;

3. Main production of hotspot material occurred at the Galápagos hotspot; and

4. Because of the northward shift of the Cocos-Nazca spreading system, the amount of hotspot material transferred to the Cocos plate and represented by the Cocos Ridge decreased.