Dating methods devonian new york shale
Faunal distributions are also employed but to a lesser extent.The distribution of nonmarine fish and marine invertebrate fossils demonstrates that Europe, Siberia, and the Canadian Arctic islands were linked and formed the bulk of Laurussia.The correlations discussed demonstrate the utility of the gamma-ray log for regional, basinwide stratigraphic studies.
The paleoequator (the site of the Equator at a point in the geological past) passed through North America and through China, which was at that time a separate landmass.
Forests and the coiled shell-bearing marine organisms known as ammonites first appeared early in the Devonian.
Late in the period the first four-legged amphibians appeared, indicating the colonization of land by vertebrates. This union of the paleocontinents of Laurentia (comprising much of North America, Greenland, northwestern Ireland, Scotland, and the Chukotsk Peninsula of northeastern Russia) and Baltica (now most of northern Europe and Scandinavia) occurred near the beginning of the Devonian Period.