The PLUME lavas erupted on Fernandina and Isabela are relatively cool. Analysis shows that they are as much as 100 degrees Celsius cooler than those in Hawaii. The cause of this is not fully understood but may be due to cooling in the lithosphere or being relatively cool at formation in the mantle.[1] They are then found in lower quantities in a horseshoe pattern north and south of the central islands mixing with the other reservoirs as it progresses east.