Beschreibung
The Sudbury structure is the largest and best-exposed remnant of a large meteorite impact structure on Earth. It hosts one of the world's largest concentrations of magmatic Ni-Cu-Pt-Pd-Au mineralization and has produced more than $100 billion worth of metal in over a century of production. It is also a unique example of a very large differentiated igneous body with remarkably simple boundary conditions. As such, it is the premier locality on Earth to study processes related to impact and planetary accretion, as well as a wide range of magmatic processes including the generation of large magmatic sulfide deposits. We propose to conduct a comprehensive program of research into the genesis and evolution of the Sudbury structure centered on a scientific drilling program. Large, formerly confidential, geological and geophysical databases belonging to industrial sponsors will be combined with the results of a concurrent program of mapping and research (structural, geochronological and petrological) to provide a synthesis of regional geology and scientific drilling of unprecedented scope. The use of newly developed 3-D database software and an immersive 3-D visualization room will contribute a unique depth to this compilation. We propose to hold an international workshop at Sudbury in late September or early October 2003 to review current geological, geophysical and geotechnical studies and results from existing exploration drilling efforts to formulate a full proposal to ICDP. This workshop will involve about 50 research groups who have contributed to the studies of Sudbury or want to participate. One to three deep boreholes will be drilled to depths of about 6 km using currently available slim-hole wireline drilling technology, with continuous core recovery. Initial down-hole geophysical probes will be replaced by a long-term semi-permanent down-hole laboratory including equipment for seismic surveys, fluid and gas sampling, and monitoring of possible deep crustal biological activity. The number and location of holes will depend on detailed objectives to be finalized after the international workshop in 2003 and after pre-site selection geophysical surveys. A full proposal will be submitted to ICDP in January 2004. The proposed project will advance knowledge of several fields of research with global scientific and economic significance at a cost between $10 M and $15 M. At the same time, the practical knowledge gained of this important ore-hosting structure may provide a great economic boon to the geological community and the people of Ontario.