Late Cenozoic geologic controls on placer-gold distribution in the Nome nearshore area

The spatial distribution of particulate gold in sediments blanketing the coastal plain at Nome is the product of a complex late Cenozoic geologic history. The diverse glacial, marine, fluvial, and deformational processes that shaped the sedimentary sequence on the emergent coastal plain have operated on the submerged continental shelf south of Seward Peninsula. Within the area extending approximately 5 km seaward of Nome, gold values in the top 20 m of sediment do not decrease seaward. The greatest concentrations are found within 4 m of the sea floor; lag-gravel deposits formed on till of the present sea floor are especially enriched. Although erosional surfaces analogous to the present sea floor may be buried within the sequence of Quaternary deposits, the extent of the gold-bearing glacial deposits that would support these surfaces is not fully delineated. Reconstructions must take into account the possibility that glaciers advanced onto the coastal plain during a period of high relative sea level. -from Authors