Array Data for Analog Mapping of Vegetation in Eastern North America: readme file
-----------------------------------------------------------------------
               World Data Center A for Paleoclimatology
-----------------------------------------------------------------------
NOTE: PLEASE CITE ORIGINAL REFERENCES WHEN USING THIS DATA!!!!!

CONTRIBUTORS: R.S. Webb and J.T. Overpeck
NAME OF DATA SET: Array Data for Analog Mapping 
of Vegetation in Eastern North America 
IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 94-007
SUGGESTED DATA CITATION: 
Webb, R., 1994, Array Data for Analog Mapping of Vegetation, North America.
IGBP PAGES/World Data Center-A for Paleoclimatology 
Data Contribution Series # 94-007.  NOAA/NGDC Paleoclimatology Program,
Boulder CO, USA.

ORIGINAL REFERENCE:
Overpeck, J.T., Webb, R.S. and Webb, T. III, 1992, Mapping eastern North 
America vegetation change over the past 18,000 years: no-analogs 
and the future, Geology, 20, 1071-1074.

DATE OF DATA GENERATION:  July 6, 1992
GEOGRAPHIC REGION: Eastern North America, 100km x 100km equal area grid;
see latlonxy.dat file for conversion.  
352 lake and mires with sediment cores analyzed for fossil pollen.

PERIOD OF RECORD: 0 - 18,000 YBP
LIST OF FILES: Readme, ModrnVeg.dat, FossVeg.dat, LatLonXY.dat, 
NumberTo.veg (variable names and conversion).

DESCRIPTION:
11,700 fossil pollen samples; 1744 modern pollen samples. 
21 pollen taxa included in analyses: Alnus, Fraxinum, Populus, Tilia, Fagus, 
Betula, Ulmus, Abies, Celtis, Corylus, Tsuga, Carya, Ostrya/Carpinus, 
Quercus, Pinus, Prairie, Cyperaceae, Picea, Liquidambar, Platanus, Juglans, 
Methods including references:
analog/no anolog vegetation assigned to each vegetation type as described 
by Overpeck, J.T., Webb, R.S. and Webb, T. III, 1992.  These vegetation types
were assigned to a 100x100km at 1000 year intervals using a three dimensional,
time-space, interpolation scheme. To generate maps the paleocoast line/ocean
and Laurentide Ice Sheet were overlain to mask out appropriate portions of 
equal area grid boxes.
Chronostratigraphic information:
age estimates are based on uncalibrated based on radiocarbon dates