Pleistocene shore lines on the islands of Oahu and Maui, Hawaii

After being deeply dissected by streams, both Oahu and Maui were deeply submerged, perhaps as a result of isostatic adjustment. On Oahu this submergence was in excess of 1200 feet, but no definite measure is yet available on Maui. Thereafter, a series of shore lines, possibly eustatic, were developed synchronously on both islands during the Pleistocene. Their names and levels in relation to present sea level, tabulated with the oldest at the top, and all in order of age, are given below: Shore lines on Oahu and Maui Name Feet above (+) or below (-) present sea level Olowalu +250, Kahuku+55 Kahipa-300, Kaena+95 Laie+70 Waialae (?) +40 (?) Waipio -60, Waimanalo+25 Present 0. The shore lines above sea level were determined from fossiliferous beach conglomerates or nips cut in lithified dunes, except the 40-foot stand the existence of which is still questionable, although terraces occur at this level. The depths of the submerged shore lines were determined from various submerged features, such as tree molds, lithified dunes, lava-filled valleys, and platforms. Their position in the sequence was determined by erosional unconformities in the marine deposits. Such fossil evidence as exists indicates that warmer temperatures existed during times of high seas than during low seas. A few of these shore lines have already been found on all the other inhabited Hawaiian Islands, and all of them may be found later when the islands are studied in detail.

This record provided courtesy of AGI/GeoRef.