Lava erupts along the axis of mid-ocean ridges as a result of tectonic plates spreading apart. These lavas, also called mid-ocean ridge basalts (MORBs), can vary in their composition as a function of magmatic processes occurring before eruption, or due to variation in the mantle sources they are derived from.
For this research project, we will be pairing high-precision geochemical measurements of individual lava flows with paleo-intensity measurements to identify changes in magma chemistry through time at the SEPR. Geochemical measurements will also aid in linking individual lava flows to eruption events along the mid-ocean ridge so that we can constrain the volume and frequency of eruptive events at the SEPR. We will compare our data to existing data sets, like that of 9ºN of the EPR where the rate of spreading is slower, to test how spreading rate affects magmatic activity and oceanic crustal growth.
Above: Doubly-polished chip of basalt glass. The little squares inside are crystals and the spheres are vesicles filled with mostly CO2 that exsolved from the magma upon eruption.
Left: cross section of a pillow basalt--the rim is coated in manganese oxide, which accumulates at a rate of ~1mm/Ma, so this is probably a few million years old. The orange band is glass that has been oxidized and weathered. In the interior you can see olivine and plagioclase crystals.