Recent Topics Posters
Baghai-Riding, Nina , Hotton, Carol .
Regional Climatic Signals Complicated by Local Factors in Late Jurassic Morrison Palynofloras.
In contrast to the rich and well-understood vertebrate fauna of the Late Jurassic Morrison Formation, the megaflora of this vast and important terrestrial deposit remains sparse and poorly studied. Here we present a progress report on our ongoing study of Morrison Formation palynofloras to understand plant diversity and its relationship with climate during this interval. A previous analysis, using spore-pollen ratios and relative diversity and focusing on the upper part of the Morrison, demonstrated apparent increasing moisture to the north, whereas conditions in the southern reaches of the formation (Arizona and New Mexico) appear to have been quite xeric. Spore-pollen ratios from six new sites in Colorado, Utah and Wyoming, including members underlying the upper Morrison Brushy Basin Member, do not display the same clear latitudinal gradient; instead, certain sites show excessive abundance of a few spore taxa, probably reflecting a very local source. Spore-pollen ratios alone are an inadequate measure of regional climate. Spore and overall palynomorph diversity, as well as additional sampling from New Mexico, Wyoming and Montana and precise determination of local depositional environment, will lead to a better understanding of the relationship between climate and vegetation in the Morrison.
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1 - DELTA STATE UNIVERSITY, Division Of Biological & Physical Sciences, Caylor Hall Room 235, CLEVELAND, MS, 38733, USA
2 - National Institute of Health, National Library of Medicine, National C, Bethesda, Maryland, USA
Presentation Type: Recent Topics Poster
Location: Khorassan Ballroom/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 5:30 PM