Multiple glaciation of Mauna Kea, Hawaii

Abstract

Mauna Kea, Hawaii (13,784 feet), was glaciated four times during a period presumably correlative with the ice age elsewhere. Snow mantles Mauna Kea during winter but banks rarely survive the summer. Evidence is abundant not only for the latest glacial stage in the summit area but also for three earlier glacial advances in the zone outside and below the youngest moraine. The four indicated stages have been named, beginning with the latest, the Makanaka, Waihu, Pohakuloa, and pre-Pohakuloa stages. Distinguishing features of the several drifts are: Stratigraphic position. The three earlier ones lie under successive series of late lava flows. Moderate weathering and surface staining (to brown) of the older drifts. Climate has probably been periglacial throughout Pleistocene and recent time. Lithologic differences due to derivation from different series of surface lavas. Matrices of the older drifts are partly tuffaceous indicating contemporary volcanism. In places the oldest drifts are well-indurated tillite. The drifts are dominantly boulder beds, much water-washed. Boulders are somewhat faceted but only faintly striated. Striated pavements are known under the older drifts, but glacial erosion was generally feeble. Glaciers in the pre-Pohakuloa stage descended to about 7000 feet but only to 10,200 feet in the latest stage. Interglacial processes other than extrusive vulcanism are little known. Climate is now subarctic above the timber line; and significant soils probably were never developed.