Percent

        |
     5  +                             o
        |
        |
        |
        |
     4  +
        |
        |                           o
        |                        o   o o
        |           E           o o
     3  +         D
        |             F       o
        |                    o o   o
        |   A              oo           o  oooo
        |                                o       o
     2  +     B C                         o    oo o
        |                                          oo
        |                                            oo o o
        |                                              o o ooo oo
        |                                                     o
     1  +                                                        o o
        |                                                         o
        |
        |
        |
     0  +
            ----------- // -----+---------+---------+---------+-----
                              1960      1970      1980      1990

                                    Year

Figure 2. Publications indexed under Paleobotany and Palynology as a percentage of all publications indexed in GeoRef

A = Overall percentage for all years before 1905, B = 1905 to 1914, C = 1915 to 1924, D = 1925 to 1934, E = 1935 to 1944, F = 1945 to 1954. All other points are for one year only.

Percentages are based on numbers of publications indexed on the GeoRef bibliographic database (a commercial product of the American Geological Institute) on CD-ROM, through September 1995. All items in the database are indexed by year of publication and by a controlled vocabulary of terms as defined by a specialized thesaurus (Goodman 1994). The percentage of items classified under the thesaurus terms Paleobotany and Palynology in the database has declined over the past three decades, following a decade of rapid growth (including 1966, an exceptional year). However, the absolute number of items has increased dramatically.

See Table 2.


References Cited

Goodman, Barbara A., editor (1994) GeoRef Thesaurus. Seventh Edition. American Geological Institute.