Channelling of hydrothermal fluids during the accretion and evolution of the upper oceanic crust: Sr isotope evidence from ODP Hole 1256D

摘要

ODP Hole 12560 in the eastern equatorial Pacific is the first penetration of a complete section of fast spread ocean crust down to the dike-gabbro transition, and only the second borehole to sample in situ sheeted dikes after DSDP Hole 504B. Here a high spatial resolution record of whole rock and mineral strontium isotopic compositions from Site 1256 is combined with core observations and downhole wireline geophysical measurements to determine the extent of basalt-hydrothermal fluid reaction and to identify fluid pathways at different levels in the upper ocean crust.