|Title||Estimating tectonic uplift of the Cape Fear Arch (southeast-Atlantic coast, USA) using reconstructions of Holocene relative sea level.|
|Publication Type||Journal Article|
|Year of Publication||2014|
|Authors||van de Plassche O, Wright AJ, Horton BP, Engelhart SE, Kemp AC, Mallinson DJ, Kopp RE|
|Journal||Journal of Quaternary Science|
We use relative sea-level (RSL) reconstructions and a spatiotemporal statistical model to estimate the rate of uplift of the Cape Fear Arch, a Mesozoic structural high, during the last ∼4000 years. We reconstructed RSL using 12 radiocarbon-dated samples of basal salt-marsh sediment preserved at Elizabeth Creek Marsh on the Cape Fear River. The new data show that RSL rose by ∼3 m during the past ∼4.6 ka at an average rate of 0.67 ± 0.12 mm a−1. RSL reconstructions from other sites in southern North Carolina (which have rates of 0.91 ± 0.10 to 0.84 ± 0.24 mm a−1) probably show (P > 0.9) higher rates of regional RSL rise for the same period, while sites from northern South Carolina (which have rates of 0.72 ± 0.17 to 0.80 ± 0.21 mm a−1) probably (P > 0.67) show the same. We attribute the differences between Elizabeth Creek Marsh and neighboring regions to uplift of the Cape Fear Arch, which we estimate to be 0.24 ± 0.15 mm a−1. Uplift of the arch may be responsible for lower rates of 20th century RSL rise recorded by the Wilmington tide gauge relative to rates measured elsewhere along the US mid-Atlantic coast.