An important continental aerosol component, up to 70% of the total dust load during the spring, has been resolved from the local basaltic component using short time-step (3.7 hr) sampling at the Hawaiian Volcano Ovservatory (HVO), a site below the inversion layer at 1.2 km altitude. The median continental contribution for approximately 2-week periods from mid-March to mid-June 1979 ranged from 1 to 2 μg m-3, whereas from mid-June to early September 1979 this component was not found, being less than the detection limit of (1)/(3) its spring magnitude. Over the 6-month period, the median concentrations for the basaltic aerosol ranged from about 0.2 to 18 μg m-3, a variation associated with local rainfall. This basaltic component exhibits a strong diurnal variation, resulting from the local wind regime, with a ratio of a mid-afternoon maximum to an early morning minimum of up to 20 or more. Of the six lithophilic elements examined (Al, Si, K, Ca, Ti, and Fe), Si shows the greatest earth/air fractionation, with the continental and local basaltic aerosols being depleted by more than 35% relative to an average crustal and Hawaiian basaltic rock composition, respectively. Time series analysis of the concentrations and a detailed examination of the element ratios indicate that local and continental soils are the only important determinants of the overall aerosol composition at this site for these elements. Compositional differences between the continental dust at HVO and that sampled concurrently at the Mauna Loa Observatory (3.4 km altitude) may be due to the presence of two distinct dust plumes over Hawaii originating from different desert regions in Asia.