Project Description
Oceanic crust covers more than 70% of Earth’s surface, and it is generated along narrow volcanic zones that snake through the world’s oceans where tectonic plates diverge. The goals of this study are related to better understanding the processes involved in crustal formation. The project uses crustal samples recovered during International Ocean Discovery Program (IODP) Expedition 360 to Atlantis Bank in the Indian Ocean. Goals of the expedition include improving our understanding of: (1) the interaction between tectonic and magmatic extension at slow volcanic spreading centers; and (2) the contribution of magnetic minerals in the lower oceanic crust to a magnetic signal measured at the sea surface. By measuring the ancient magnetization recorded in the rocks, we can calculate the amount of rigid rotation the crust has undergone at this location over the past ~11 million years. By measuring the alignment of magnetic minerals, we can further understand how the crust deformed while at high (near magmatic) temperatures. Finally, by using measured magnetic properties of the rocks, we can model how various rock types within the crust contribute to the observed magnetic field at the sea surface.
Tasks and Responsibilites
The student will use two forms of magnetic data to assess deformation at relatively high (>600°C) and low (<600°C) temperatures. S/he will use alternating magnetic field to demagnetize samples and then interpret the data in terms of the ancient magnetization direction carried by the rocks. The student will then further interpret the data within the broader context of existing data from thermally demagnetized samples and calculate the minimum amount of tectonic rotation at temperatures 600°C.
Desired Qualifications
None Listed