Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network

  Advanced Search  

11Rock Magnetic Characterization Through an Intact Sequence

Summary: 11Rock Magnetic Characterization
Through an Intact Sequence
of Oceanic Crust, IODP Hole 1256D
Emilio Herrero-Bervera, Gary Acton, David Krása,
Sedelia Rodriguez, and Mark J. Dekkers
Coring at Site 1256 (6.736N, 91.934W, 3635 m water depth) during Ocean Drilling
Program (ODP) Leg 206 and Integrated Ocean Drilling Program (IODP) Expeditions
309 and 312 successfully sampled a complete section of in situ oceanic crust, includ-
ing sediments of Seismic Layer 1, lavas and dikes of Layer 2, and the uppermost
gabbros of Layer 3. The crust at this site was generated by superfast seafloor spread-
ing (>200 mm/yr full spreading rate) along the East Pacific Rise some 15 Ma ago.
One goal of drilling a complete oceanic crust section is to determine the source of
marine magnetic anomalies. For crust generated by fast seafloor spreading, is the
signal dominated by the upper extrusive layer, do the sheeted dikes play any role,
how significant is the magnetic signal from gabbros relative to that at slow spread-
ing centers and what is the timing of acquisition of the magnetization? To address
these questions, we have made a comprehensive set of rock magnetic and paleomag-
netic measurements that extend through the igneous interval. Continuous downhole
variations in magnetic grain size, coercivity, mass-normalized susceptibility, Curie


Source: Acton, Gary - Department of Geology, University of California, Davis


Collections: Geosciences