Abstract The elemental compositions of relatively unweathered Fe-Ti oxide grains, mostly ilmenite, separated from 83 samples collected from late Pleistocene to modern beach sands in Virginia and North Carolina were compared to those of 72 samples from five potential source rivers, the Roanoke, James, Potomac, Susquehanna, and Hudson Rivers. The composition of the Fe-Ti oxides from the toe of the Suffolk Scarp have a much different provenance than do younger beach deposits to the east. Based on discriminant analysis classification of the Fe-Ti oxide compositions with potential source rivers, the Suffolk Scarp beach is inferred to have been derived primarily from the James River; the younger beaches, including modern beach deposits of the Outer Banks, North Carolina, are inferred to have been primarily from the Susquehanna River with minor input by the Hudson River via longshore transport and reworking of shelf sands. The difference in provenance is due primarily to the origin of the Suffolk Scarp beach by erosion of older estuarine units in a protected-bay beach setting, whereas the younger beach deposits were derived from reworking of shelf sands, probably bay-mouth sand deposits (massifs), in an unprotected or barrier-beach setting. Subtle differences in the Fe-Ti oxide compositions among beach deposits are due to changes in the mix from the different river sources. Discrimination of the differences allows for a clearer understanding of the interrelation among those coastal-plain ridges and scarps that contain the beach sands.

An intensive search for fossils in Taconic sequence strata in the region of Columbia County, New York, produced three Lower Cambrian, two Middle Cambrian, and two Upper Cambrian trilobite faunas, of which only the oldest Early Cambrian fauna was previously known from the area. All these faunas contain diagnostic genera and species, allowing precise correlation with Cambrian strata of other regions of North America and Europe. The trilobites occur in limestone units which are generally lenticular and interstratified with a much greater thickness of grey, green, or black unfossiliferous shales. These findings indicate that there is no unconformity between the Lower Cambrian and the Lower Ordovician strata of the Taconic sequence in the southern portion of the Taconic allochthon. It is likely, instead, that an essentially complete sedimentary sequence extends from the Cambrian system upward into the Lower Ordovician. Several sections were measured, and are described in detail, with lists of the fossils observed at various stratigraphic positions. For the first time in the study of the Cambrian of the Taconic sequence, several diagnostic faunas in unquestionable stratigraphic order have been collected from a single section. Aspects of the stratigraphy of the Columbia County region are compared with those determined by recent investigations of the northern portion of the Taconic allochthon, and sedimentary aspects are briefly described.