MORB AFM Ternary Diagram

Title: MORB AFM Ternary Diagram
Description: This ternary diagram, generated using a representative dataset (10% wt intervals of SiO2) of global MORBs, suggests that MORBs are tholeiitic. MORBs are enriched in Fe and Mg and relatively depleted in alkalis, suggesting that they did not significantly fractionally crystallize before eruption. This is consistent with our knowledge of MORBs, particularly at fast-spreading ridges where magma erupts almost constantly. If this data set only focused on slow-spreading ridges, perhaps the data would be slightly more alkaline, as magma spends more time in the chamber before eruption.
Subject: Petrology 2015 Final Project: MORB
Creator: Devon Gorbey
Source: PetDB
Mediator: Tamara Carley