Randall C. Orndotffl’s scientific contributions

The Shenandoah Valley in Virginia is part of the ex- tensive Great Valley section of the Valley and Ridge physiographic province. The Great Valley is eroded, folded Cambrian through Middle Ordovician carbonate rocks and Upper Ordovician fine-grained siliciclastic lithologies. Studies by Sando (1957, 1958) established the stratigraphic position of the Cambrian-Ordovician boundary in the Great Valley carbonates of south-cen- tral Pennsylvania and western Maryland, but the po- sition of this systemic boundary in Virginia has not been documented. The preliminary results of a biostrati- graphic study utilizing conodont and trilobite faunas to determine more precisely the position of the Cambrian- Ordovician boundary in the northwestern Virginia area are reported. This is a joint study and researchers are listed alphabetically; Orndorff is responsible for the conodont work, and Taylor and Traut are responsible for the trilobites. Two sections in the Shenandoah Valley were mea- sured and sampled (Figure l). Conodonts and trilobites were recovered from a section along Narrow Passage Creek, 3 km southwest of Woodstock, Shenandoah