A power swivel provides the rotational force to drill consolidated subsurface strata while an unrestricted airflow through the swivel and down a drill string remove cuttings from the borehole. The power swivel is configured to mount on direct push/driven-vibrating equipment, such as a cone penetrometer, to eliminate the need for a conventional drilling rig when a consolidated layer is encountered during direct push/driven-vibrating operations. A drilling nipple and pack-off are provided near the surface to maintain the air flow during drilling and to direct the cuttings to a desired location. Also, a dual-valved air delivery system provides safe, remote-controlled air flow to the swivel.