Tertiary and Quaternary vegetation history of the Great Salt Lake, Utah, USA

Owen K. Davis, Thomas E. Moutoux

Research output: Contribution to journalArticle

26 Scopus citations

Abstract

Pollen analysis of 5 wells drilled to bedrock in the Great Salt Lake, Utah, USA provide a record vegetation change over the last ca 13.5 Ma. Over 440 pollen samples have been counted. The longest record presented is for the mid-lake Bridge Well. Close-interval (3-10 Ka) sampling is presented for the upper Indian Cove well. Chronologic control is provided by identification volcanic tephra and by K/Ar, Ar/Ar, and fission-track dates. Ash determinations are based on electron microprobe analyses of iron, calcium, and other elements compared to Neogene ash data at the University of Utah. Sedimentation begins 38 Ma, with good pollen preservation is sediments younger than 13.5 Ma, and no obvious gaps in sedimentation after 6 Ma. The upland vegetation is desert from the late Miocene onward, with Sarcobatus and Ephedra pollen dominance during the late Miocene (<5 Ma). Chenopodiaceae-Amaranthus, and Artemisia gain dominance during the Pliocene (5-2.5 Ma) and early Pleistocene. Pinus and Artemisia sharply increase in the late Pleistocene (0.75 Ma). The pollen of 'Tertiary exotics' (elm, hickory, Ostrya-Carpinus) is rare, but persists into the Pleistocene. Major vegetation - climatic events occur 3.7 and 2.5 Ma. Increased pollen concentration and sedimentation rate after 310 Ka are attributed to the diversion of the Bear River into the Bonneville Basin. Glacial-interglacial cycles appear as alternations of Chenopodiaceae-Amaranthus (interglacial) vs Artemisia (glacial) during the Pliocene and early Pleistocene, and of Cupressaceae, Sarcobatus, and Gramineae (interglacial) vs Picea, Abies, and Pseudotsuga (glacial) during the late Pleistocene. Pluvial cycles are separated by interpluvial peaks in percentages of wetground and aquatic types. Six interpluvials are indicated during the last 759 Ka, with pluvial cycles of ca 100 Ka cyclicity back to 1.5 Ma.

Original languageEnglish (US)
Pages (from-to)417-427
Number of pages11
JournalJournal of Paleolimnology
Volume19
Issue number4
DOIs
StatePublished - Jan 1 1998

Keywords

  • Climate
  • Great Salt Lake
  • Palynology
  • Pleistocene
  • Pliocene
  • Pluvial

ASJC Scopus subject areas

  • Aquatic Science
  • Earth-Surface Processes

Fingerprint Dive into the research topics of 'Tertiary and Quaternary vegetation history of the Great Salt Lake, Utah, USA'. Together they form a unique fingerprint.

  • Cite this