Abstract:

Frustration and New Year Caves are active between-caves, paralleling in plan and profile the ephemeral stream bed of the V-shaped valley in which their entrances are found. The main streamsink in this valley system feeds their stream, which in turn supplies Zed Cave, a short outflow cave just outside the mouth of this valley. This modest derangement of surface drainage pattern is in keeping with the caves which show slight vadose modification of epiphreatic cave development. Although these active caves are young, they probably formed prior to a Late Pleistocene cold period (30,000 to 10,000 BP) on the basis of soils evidence. Clown Cave on the brow of the valley, a dry cave with indications of sluggish phreatic development, is related to a planation phase of Middle or Lower Tertiary age before valley incision. Bow and Keyslot Caves are abandoned in and out and outflow caves respectively, formed when the surface stream channel was a few metres above the present valley bottom so they antedate the active river caves a little. This hydrologically independent part of the Cooleman Plain mirrors in most respects the major parts draining to the Blue Waterholes, differing chiefly in the greater proportion of between-caves discovered so far.