Macquarie Island: A window into the oceanic crust and upper mantle

• Other Authors: AADC (owner), AADC, DATA OFFICER (distributor), AADC, DATA OFFICER (custodian), AU/AADC > Australian Antarctic Data Centre, Australia (hasAssociationWith), Australian Antarctic Data Centre (publisher), Australian Antarctic Division (sponsor), CAWOOD, PETER (collaborator), CAWOOD, PETER (hasPrincipalInvestigator), CAWOOD, PETER (author), Cawood, P. (originator)
• Format: Dataset
• Language: unknown
• Published: Australian Ocean Data Network
• Subjects: geoscientificInformation; oceans; EARTH SCIENCE > SOLID EARTH > GRAVITY/GRAVITATIONAL FIELD > CRUSTAL MOTION > OCEAN CRUST DEFORMATION; MACQUARIE ISLAND; MID-OCEAN RIDGES; OCEANIC LITHOSPHERE; OPHIOLITES; SHEETED DYKES; AMD/AU; CEOS; AMD; OCEAN > SOUTHERN OCEAN; SOUTHERN OCEAN > GEOGRAPHIC REGION > POLAR; Macquarie Island; Southern Ocean
• Online Access: https://researchdata.edu.au/macquarie-island-a-upper-mantle/2820987

Progress Code: completed Statement: Dates provided in temporal coverage are approximate only, and represent the beginning and end date of the Macquarie Island season in 2002/2003. Because of the inaccessibility of the deep-ocean floor, our knowledge about the composition and structure of the oceanic crust is very limited. Macquarie Island is the only fragment of ocean crust exposed above sea-level in the world, providing a unique opportunity to study the ocean crust directly in unprecedented detail. From the abstract of the referenced paper: Macquarie Island preserves largely in-situ Miocene oceanic crust and mantle formed at a slow-spreading ridge. The crustal section on the island does not conform to a simple 'layer cake pseudo-stratigraphy', but is the result of multiple magmatic episodes. Macquarie Island crust did not grow by top-down cooling, but rather from the base up. Peridotites cooled first and formed the basement into which gabbro plutons were intruded. This was followed by cooling and deformation, and by intrusion of dykes that fed a sheeted dyke-basalt complex. Finally, lava filled grabens were formed. These relative age relations rule out simple co-genetic relations between rock units.