St. Helena Geochemistry

Title: St. Helena Geochemistry
Description: Harker Diagram - The Harker Diagram (Figure 1) shows that the Ocean Island Basalts of the St. Helena Chain show a decreasing concentration in compatible elements (i.e. Magnesium) coincided with a relative increase in the concentration of incompatible elements (i.e. Potassium and Ytterbium). This suggest that the magma sourced was less primitive, evolving over time as it ascended through the mantle.
Subject: Ocean Island Basalts
Creator: Robert Ashton
Date: May 5, 2015
Mediator: Tamara Carley
Rights Holder: Lafayette College Department of Geology and Environmental Geosciences

Media: Figure 1: Harker Diagram - St. Helena Chain; Figure 2: Na2O + K2O Wt. %; Figure 4: Ternary Diagram; Figure 3: Rare Earth Elements normalized to Chondrite