THE CONTRIBUTIONS OF DONALD LEE JOHNSON TO OUR UNDERSTANDING OF THE QUATERNARY HISTORY OF THE CALIFORNIA CHANNEL ISLANDS

For nearly 50 years, native Californian Donald Lee Johnson of the University of Illinois had a love affair with the California Channel Islands. He studied the soils, geomorphology, paleozoogeography, and Quaternary paleoclimatic history of all eight islands during the course of his career, much of it with his wife Diana Johnson. Charles Darwin was fascinated, challenged, and inspired by his visit to the Galapagos Islands; the same was true for Don with the California Channel Islands. In the several decades of his studies, Don made a number of memorable contributions to our understanding of these diverse islands. Among these are: (1) the recognition that carbonate dunes, often cemented into eolianite, are markers of glacial periods on the Channel Islands, derived from offshore shelf sediments during lowered sea level; (2) the identification of beachrock on the Channel Islands as the northernmost occurrence of this feature on the Pacific Coast of North America; (3) recognition of both the biogenic and pedogenic origin of caliche "ghost forests" and laminar calcrete forms on the Channel Islands; (4) providing the first soil maps of several of the islands, showing diverse pathways of pedogenesis, including the origin of stone pavements on marine terraces by an understanding of the dynamics of swelling-clay-rich Vertisols; (5) pointing out the importance of fire in Quaternary landscape history on the Channel Islands, based on detailed stratigraphic studies; and (6) perhaps his greatest contribution: the origin of Channel Islands pygmy mammoths of Pleistocene age, due not to imagined ancient land bridges (for which there was never any structural or geomorphic evidence), but rather due to the superb swimming abilities of proboscideans, combined with lowered sea level, favorable paleowinds, and an attractive paleovegetation on the Channel Islands. Don was a classic natural historian in the great tradition of Charles Darwin and George Gaylord Simpson, his role models. He was a geographer, geologist, biologist, soil scientist, and geoarchaeologist who had a holistic view of landscape evolution. Don's work will stand for many years and is an inspiration to those working on the California Channel Islands today.