The Plutonic Foundation of a Very Slow-Spreading Ridge

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9618442 Dick This award will support a marine geological and geophysical study of exposed lower ocean crust in the southwest Indian Ocean. Exposed crustal rocks on shallow uplifted seafloor were discovered in this region during Ocean Drilling Program operations. ODP site 735B sampled a 400 meter vertical section of gabbros in this area providing a detailed record of crustal formation processes. To date , however, it has been difficult to place these results into a local context since no data are available on surrounding seafloor geology. The present project will rectify this situation by undertaking detailed near bottom observations and sampling. Canadian scientists will provide the ROV ROPOS as primary survey vehicle, and rock drill would be modified for deployment on ROPOS to allow direct sampling of observed rocks.The primary objective is to provide detailed near bottom examination and sampling of seafloor to tie existing ODP data to local environment and to provide detailed site survey for drilling to be proposed which would sample at sites surrounding existing hole. Additional work would include newly developed British rock drill to provide deeper sampling than could be done from ROPOS vehicle. Samples and data would be used to identify crustal formation process at this unique exposure of lower crustal rocks. ***