Volume 37 – Issue 1 (Mar 1972)

Phytoplankton Composition at Lake Drummond in the Dismal Swamp, Virginia. Summer 1970

ABSTRACT A summer study of the phytoplankton in Lake Drummond is discussed. The lake is located in the center of the Dismal Swamp region of southeastern Virginia. There was little species diversity of the phytoplankton which was composed mainly of diatoms, desmids, and phytoflagellates. The dominant species were <em>Asterionella formosa</em>, <em>Melosira Herzogii</em>, <em>Closteriam gracile</em>, and <em>Staurastrum paradoxum</em>.

Read / Download Full Article »

Stratigraphic Placement of the Dunkard: A Review of the Paleobotanical and other Evidence

ABSTRACT The age designation of Dunkard strata has been a controversial subject for more than 90 years. These rocks have been designated by various authors as Pennsylvanian, Permian, transitional Permo-Carboniferous and partially Permo-Carboniferous: partially Permian. Evidence cited in substantiation of each of these claims has varied from lithological to paleontological to paleobotanical, but the preserved mega-flora as described by Fontaine and White (Rept. PP., 2nd Pa. Geol. Survey) in 1880 forms the basis for most of the age assignments. In some instances, fossilized organisms have apparently been cited as Permian because of their occurrence in Dunkard strata rather than through interpretation of the organismal characteristics. Palynological studies which contrast the flora of the Dunkard with the Virgilian, Gearyan and basal Cimarronian of the Midcontinent area indicate that the Dunkard is no younger than Virgilian which has always been classified as undoubted Pennsylvanian. In general, there seems to be no lithologic,

Read / Download Full Article »