2005/10/27 by Joshua Schwartz, Barbara E. John, M. J. Cheadle +4 · 2 citations
Earth and Planetary Sciences · Computer Science · #Geological and Geochemical Analysis #Geochemistry and Geologic Mapping #earthquake and tectonic studies
paper · doi:10.1126/science.1116349
openalex publication_date 2005/10/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/23
Nineteen uranium-lead zircon ages of lower crustal gabbros from Atlantis Bank, Southwest Indian Ridge, constrain the growth and construction of oceanic crust at this slow-spreading midocean ridge. Approximately 75% of the gabbros accreted within error of the predicted seafloor magnetic age, whereas approximately 25% are significantly older. These anomalously old samples suggest either spatially varying stochastic intrusion at the ridge axis or, more likely, crystallization of older gabbros at depths of approximately 5 to 18 kilometers below the base of crust in the cold, axial lithosphere, which were uplifted and intruded by shallow-level magmas during the creation of Atlantis Bank.