Potential for expanding a 65 k.y. time series from sediment-hosted glasses near the Juan de Fuca Ridge

Abstract:

Established records of ocean ridge processes rely on traditional sampling methods that provide either extensive time-intervals with coarse resolutions, or relatively short periods of high-resolution. A recent approach to understanding ocean ridge magmatism through time-series of sediment-hosted volcanic glass offers the possibility of constructing high-resolution volcanic stratigraphy extending greater than 600 kya. Several piston cores were obtained from sites of differing crustal age, on transects extending west of the Juan de Fuca Ridge, and were expected to contain volcanic glass from different periods of time. Using samples from cores AT26-19 20PC and 32PC, and previous records from AT26-19 12PC, time-series of magmatic compositions were constructed. The relative chronologies of sediment-hosted glasses were dated by correlating isotope stratigraphies of benthic foraminifera with their sediment layers. By comparing these data with the previously constructed record, alongside the qualitative properties of sediment-hosted glasses, the pending results will offer insights into changes in ocean ridge magmatism, submarine glass dispersal, and into the validity of this recently developed approach. Ultimately, this research may inform our broader understanding of ocean ridge processes, biogeochemistry, and abrupt climate change.