The Molloy Core Complex: Petrological studies of mantle rocks

Title

The Molloy Core Complex: Petrological studies of mantle rocks

Supervisors

Rolf B. Pedersen (hovedveileder), Anders Bjerga (medveileder)

Project description

On a research cruise during the spring of 2022 the Center for Deep Sea Research proved the existence of an oceanic core complex in the Molloy-area by the entrance to the Fram Strait. During this cruise, aboard the FF Kronprins Haakon, samples were taken of mantle rocks from several parts of the core complex using the ROV Ægir. These unique samples will provide important new information about the mantle beneath the Arctic region, and about geodynamic conditions linked to the transition from continental rifting to seabed spreading.

This master thesis will provide the first description of the petrography and geochemistry of the sample material. A main goal of the thesis is to document the geochemical and isotopic geochemical composition of the mantle samples and how the elemental and isotopic composition is in relation to mantle samples from the Mohns Ridge to the south, the Gakkel Ridge to the north, and the Sverrefjell volcano on Svalbard to the east. An important part of the thesis is to define magmatic and metasomatic events that have influenced the composition of the mantle, and to investigate if any of these events can be attributed to the ongoing opening of the Fram Strait and exhumation of the mantle in this area.

The study will be based on sample material that has already been collected. The analytical work will include microscopy and mineral analyzes by SEM/EDS, Raman spectroscopy, and LA-ICP-MS. Rock analyzes will be carried out using ICP-OES/MS. Isotope analyzes will also be carried out on primary mineral phases using TIMS, ICP-MS and SIMS.