A large granitic dropstone, the 'Robertson dropstone' was recently discovered embedded in the uppermost part of the Cleveland Shale Member of the Upper Devonian Ohio Shale in Logan Hollow Branch, approximately 8 km northwest of Morehead, Kentucky. Well-preserved miospore assemblages from grey mudrock samples immediately below, above and adjacent to the dropstone are assigned to the late Famennian Retispora lepidophyta - Verrucosisporites nitidus (LN) Miospore Biozone. LN Biozone assemblages have also been recovered from the overlying Bedford Shale at this locality.

Highly carbonized palynomorphs have been recovered from sections that include diamictites at three localities in the Appalachians, ca. 500 km to the east of Morehead, at Sideling Hill, Maryland, La Vale, Maryland, and Crystal Spring, Pennsylvania. Although these palynomorphs are highly carbonised and poorly preserved, stratigraphically important taxa can still be recognized, allowing the diamictite units in these sections to be assigned to the LN Biozone and the preceding Retispora lepidophyta - Indotriradites explanatus (LE) biozone. The palynological evidence supports previous lithostratigraphic and gamma-ray correlations between the Kentucky and Appalachian sections. It also provides firm evidence for the first time of a late Famennian age for the alpine glaciation/deglaciation responsible for deposition of these diamictites and related glaciogenic sediments such as the laminites at Crystal Spring.

The sections studied are correlated palynologically with Gondwanan, high-palaeolatitude, marine diamictites at Bermejo, Bolivia. Late Famennian miospore assemblages from Euramerica are similar to those from western Gondwana, though some distinctive taxa are restricted to the latter. However, some of the index species of the European-based miospore zonation including Indotriradites explanatus and Verrucosisporites nitidus are often relatively rare in both western Euramerica (USA) and western Gondwana (Bolivia) compared to eastern Euramerica (Europe).