DOES THE MOZAMBIQUE RIDGE BELONG TO MOZAMBIQUE?

• Main Authors: Watkeys, M., Jokat, Wilfried
• Format: Conference Object
• Language: unknown
• Published: 2006
• Subjects: Antarc*; Antarctica
• Online Access: https://epic.awi.de/id/eprint/14465/; https://hdl.handle.net/10013/epic.24768

The confirmation of the presence of continental fragments in the ocean basins has now moved from a matter of scientific interest to that of political importance as countries seek to expand their boundaries in terms of the new proposals concerning the Exclusive Economic Zone. One such fragment is the Mozambique Ridge that has the potential of being claimed by Mozambique and the Republic of South Africa. The ridge extends from the coast of central Mozambique southwards to 35oS, separating the Natal Valley to the west from the Mozambique Channel to the east, rising up to 3 km above the flanking oceanic crust on either side. Up to now the continental origin of this ridge has been generally accepted, despite the problems that such a fragment imposed on a tight refit of SE Africa and Antarctica. This interpretation was based on dedging results which yielded rocks such as kinzingite that were correlated with similar lithologies in the Kibaran belts of KwaZulu-Natal, South Africa and Drönning Maud Land, Antarctica. Dredging also brought up basalts, which were considered to be overlying this continental basement. These constraints were used for the geophysical modelling of gravity over the ridge.As part of a programme aimed at establishing the break-up events between Africa and Antarctica, a marine geophysical survey was undertaken in region from May to July 2005. The survey commenced just south of the Mozambique Ridge and extended along its full length before covering the Mozambique Channel. Lines were aligned NE-SW and spaced at 12 nautical miles, and the survey involved measuring bathymetry, gravity and magnetics as well as dredging. It revealed that a magnetic reversal pattern occurs along the whole length of the Mozambique Ridge, so the ridge must be oceanic in origin. This pattern could be confidently correlated with the Mesozoic magnetostratigraphic timescale and also matched the magnetics reported on the ocean floor off Drönning Maud Land, Antarctica which was the conjugate margin during Gondwana break-up. This ...