Vegetational history of the Shenandoah Valley, Virginia
Vegetational history of the Shenandoah Valley, Virginia (in United States contributions to Quaternary research--Internat. Assoc. Quaternary Research, 8th Cong., Paris, 1969)
Special Paper - Geological Society of America (1969) 123: 283-296
- absolute age
- Shenandoah Valley
- United States
- Shenanadoah valley
Two pollen diagrams from Hack and Quarles Ponds, in the southern part of the Shenandoah Valley, Va., show the followingpollen assemblage zones: (1) a basal Pinus-Picea zone with abundant conifers and large amounts of herbs, with two subzones, the top being 12,720 + or - 200 yr B.P.; (2) a Quercus zone, with very little conifer and two subzones, the upper being 9520 + or - 200 yr B.P.; (3) a Quercus-Pinus zone with substantial amounts of other deciduous tree pollen. These diagrams strongly resemble those from southeastern Virginia and North Carolina and differ markedly from those farther north in areas covered by Wisconsin ice. Substantial changes in vegetation occurred at considerable distances from the ice sheets. There is support also for the hypothesis that the Appalachians served as a refuge for Pinus and Picea during at least part of Wisconsin time.