Terrigenous components in sediment core B84A from the Alpha Ridge, western Arctic Ocean, have been investigated to reconstruct the Mid to Late Quaternary variations in sedimentation, source regions, and related climate changes. The core stratigraphy, evaluated by a combination of variations in Mn content, color cycles, foraminiferal abundance, and lithological correlation, extends back to estimated Marine Isotope Stage (MIS) 12. Twelve ice rafted detritus (IRD, >250 μm) events were identified and interpreted to mostly occur during the deglacial periods. The Canadian Arctic covered by ice sheets during glacial periods is suggested to be the major source region. The IRD events likely indicate the collapses of ice sheets, possibly in relation to abrupt climate changes. Grain size analysis of B84A indicates sedimentologically sensitive components in core B84A in the silt subfractions 4~9 μm and 19~53 μm, which are inferred to be mainly transported by currents and sea ice, respectively. Downcore variability of these two fractions may indicate changes in ice drift and current strength. In accordance with previous studies in the central Arctic Ocean, average sedimentation rate in core B84A is about 0.4 cm/ka. In comparison with relatively high sedimentation rates at the margins, sedimentation in the central Arctic Ocean is limited by sea ice cover and related low bioproductivity, as well as long distance from the source regions of terrigenous sediment.