The climatic effects of major geologic events of the last 6 m.y., such as the variations in arctic and Antarctic icecaps and the uplift of major mountain ranges, are reasonably well documented in the marine realm. On land, however, such evidence is limited, and chronostratigraphic control is minimal. Only ~12 widely separated floras are available to reconstruct discrete events in the evolution of vegetation and climate of California and Oregon forests during the late Neogene, an interval in which major climatic changes are reflected in the replacement of Miocene mesophytic forests by temperate coniferous forests (Axelrod, 1977). Cores taken on the California margin during Leg 167 provide an opportunity to continuously monitor vegetation of the northwest coast of North America (using marine pollen assemblages), to set the terrestrial vegetation and climate records in accurate age frameworks provided by other components in the cores, and to directly relate late Neogene changes in oceanic and terrestrial processes. The primary objective of this survey of pollen from Ocean Drilling Program (ODP) Holes 1018A, 1020C, 1021B, and 1022C is to present an initial overview of the evolution of vegetation on the northern California margin from the upper Miocene to Holocene.
1Lyle, M., Koizumi, I., Richter, C., and Moore, T.C., Jr. (Eds.), 2000. Proc. ODP, Sci. Results, 167 [Online]. Available from World Wide Web: <http://www-odp.tamu.edu/publications/167_SR/167sr.htm>. [Cited YYYY-MM-DD]
2Lamont-Doherty Geological Observatory, Columbia Univeristy, Palisades NY 10987, USA. (Present address: Heusser and Heusser, Inc., 100 Clinton Road, Tuxedo NY 10987, USA.) heusser@lamont.ldeo.columbia.edu
Date of
initial receipt: 30 September 1998
Date of acceptance: 13 January 1999
Ms 167SR-230