New Mexico Geological Society Annual Spring Meeting — Abstracts

This report documents paleofloral localities with exceptionally well preserved fossil material in the Campanian-Mastrichtian Fruitland Formation, San Juan Basin, New Mexico. The localities are situated north of Chaco Canyon and south of Farmington, New Mexico.

The area is now known to contain five forest horizons represented by in situ fossil stumps. More than 400 in situ tree stumps and numerous isolated logs have been mapped for three of the horizons. The wood occurs silicified, completely carbonized, partially carbonized and virtually unaltered. Some wood may show evidence of burning rather than coalification. In two specimens, hematitic bark is associated with logs. Well preserved fossil leaves and other plant tissue are preserved as light brown compressions in shale or black compressions in siltstones. Three horizons and four leaf-bearing localities are known. These are located between stump horizons and represent additional forest horizons. Thus, at least eight different forests are known from the study area.

Other plant fossils include cones, possible fruits as well as one well preserved and two less well preserved coconuts. Ferns, conifers, monocots and dicots are represented by large samples. Palynological data indicates the very close proximity of the area to the interior seaway.