HALBAN Two third of the Earth’s surface is made up of oceanic crust, which forms at mid-ocean ridges and is recycled into the mantle via subduction at convergent plate boundaries. During each phase of its 200 million year lifecycle the oceanic crust plays a key role in global geochemical cycles, including the carbon cycle. The inaccessibility of the seafloor makes it difficult to study. However, fragments of ancient oceanic lithosphere that have been tectonically emplaced on continental margins provide access to complete cross-sections of seafloor. These exposed sections of oceanic lithosphere are called ophiolites. The Samail Ophiolite in Oman is the largest, best-exposed section of oceanic lithosphere in the World.
The Oman Drilling Project (ODP) is a comprehensive international drilling program that aims to sample the whole ophiolite sequence, from oceanic crust through to upper mantle, in a series of boreholes. Data collection includes analysis of rock core, geophysical logging, fluid sampling, hydrological measurements and microbiological sampling. The geoscientist, Dr. Philippe Pezard, University of Montpellier (France) is currently leading the geophysical logging of the boreholes. He shared his experience and information about the equipment used with students from the Department of Applied Geosciences at GUtech. Some students visited one of the project’s drilling sites last week.
After completion of the international research project, a large number of scientists from a broad spectrum of disciplines will use the new datasets. The ODP will address long-standing unresolved questions and undertake frontier exploration of subsurface weathering processes that lead to natural uptake of CO2 from surface waters and the atmosphere, and the nature of the subsurface biosphere in areas. Drilling operations started on December 25, 2016. Intense logging is performed currently. The ODP is funded and supported by a consortium of international institutions, including GUtech.