Late Cretaceous and Cenozoic History of North American Vegetation

Abstract

Late Cretaceous and Cenozoic History of North American Vegetation, Alan Graham, 1999, Oxford University Press, New York, 350 p. (Hardcover, $95) ISBN: 0-19-511342-X There has long been a need for a technical book on the Cretaceous and Cenozoic paleobotany of North America. Although other books have been written at the layperson's level, the recent book Late Cretaceous and Cenozoic History of North American Vegetation by Alan Graham is the first intended for a more advanced audience. The book contains nine chapters, the first four of which review background concepts and methodologies. Chapter one is a descriptive overview of the principle plant formations that comprise the modern vegetation of North America. Concise summaries for each formation concentrate on floristic composition and show the subdivisions into plant associations and regional forest types. Here, and throughout the book, Mexico is excluded from the discussion. The second chapter discusses the factors that potentially have influenced the late Cretaceous and Cenozoic history of North American vegetation. These include: aspects of climate such as El Nino events, Milankovitc variations, 18O/16O ratios, and CO2 concentrations; plate tectonic events such as orogeny, volcanism, land bridges, and exotic terranes; and catastrophes such as asteroid impacts and floods. A flow chart that increases in complexity throughout the chapter emphasizes the potential for dynamic interactions between these many influences on vegetational history. Chapter three, entitled “Context,” covers an array of topics such as the marine paleotemperature curve, global sea level changes, faunal evidence for paleoenvironments and the use of faunas for age determinations, and the concepts of geoflora and paleotropics. Chapter four focuses on the methodological approaches for paleovegetation analysis provided by palynology and paleobotany. A comparison is made between the merits of the “modern analogue method,” which uses the ecological distribution of …