Paleopedologic interpretations of soils buried by Tertiary and Pleistocene-age volcanic ashes: Southcentral Kansas, Western Oklahoma, and northwestern Texas, USA

Deposits of volcanic ash from major eruptions during the late Tertiary and early-to-middle Pleistocene in the western U.S. are interbedded with uncons olidated sediments in parts of Oklahoma, Kansas, and Texas. Soils and sedim ents at the land surface at the time of the eruptions were buried by the re latively pure (>95% glass shards) ash. The former surface soils, or paleoso ls, contain information about soil-forming processes, climates, and landsca pes of the region prior to and at the time of the eruptions. Field descript ions of the paleosols are made using pedologic nomenclature. Comparisons ar e made of paleosols buried by deposits of ash from the same eruption, paleo sols buried by deposits of ash from eruptions of different age, and paleoso ls buried by ash and soils described at the land surface today. Paleosols b uried by ash exhibit a diversity of characteristics. Ash from eruptions occ urring hundreds of thousands to more than a million years apart buried pale osols which have common characteristics. Paleosols buried by ash resemble s oils at the land surface in the region at present. Climates and landscapes of today are inferred to be similar to climates and landscapes at the times of the Tertiary and early to middle Pleistocene volcanic eruptions. (C) 19 98 Published by INQUA/Elsevier Science Ltd. All rights reserved.