Quaternary Climates and Sea Levels of the U.S. Atlantic Coastal Plain

Abstract

Uranium-series dating of corals from marine deposits of the U.S. Atlantic Coastal Plain coupled with paleoclimatic reconstructions based on ostracode (marine) and pollen (continent) data document at least five relatively warm intervals during the last 500,000 years. On the basis of multiple paleoenvironmental criteria, we determined relative sea level positions during the warm intervals, relative to present mean sea level, were 7 +/- 5 meters at 188,000 years ago, 7.5 +/- 1.5 meters at 120,000 years ago, 6.5 +/- 3.5 meters at 94,000 years ago, and 7 +/- 3 meters at 72,000 years ago. The composite sea level chronology for the Atlantic Coastal Plain is inconsistent with independent estimates of eustatic sea level positions during interglacial intervals of the last 200,000 years. Hydroisostatic adjustment from glacial-interglacial sea level fluctuations, lithospheric flexure, and isostatic uplift from sediment unloading due to erosion provide possible mechanisms to account for the discrepancies. Alternatively, current eustatic sea level estimates for the middle and late Quaternary may require revision.

A cool eastern Pacific Ocean at the close of the Last Interglacial complex

“…Interpretations of marine ostracode faunas from these and other localities are consistent with those based on the molluscan faunas (Cronin et al, 1981). Localities with ostracode data that indicate waters warmer than those of the present have been reported from 80,000 yr BP deposits at New Light, Womack, and Mears, Virginia; Moyock, North Carolina; and Scanawah Island, South Carolina (Cronin et al, 1981). Farther south, off the Florida Keys, Ludwig et al (1996) and Toscano and Lundberg (1999) dated a submerged reef to 80,000 yr BP.…”

“…Molluscan faunas from the Womack, New Light and Toy Avenue localities (around Virginia Beach, Virginia), dated to 80,000 yr BP, all contain large numbers of extralimital southern or southward-ranging species, lack any extralimital northern species, and have few or no northwardranging species (Spencer and Campbell, 1987). Interpretations of marine ostracode faunas from these and other localities are consistent with those based on the molluscan faunas (Cronin et al, 1981). Localities with ostracode data that indicate waters warmer than those of the present have been reported from 80,000 yr BP deposits at New Light, Womack, and Mears, Virginia; Moyock, North Carolina; and Scanawah Island, South Carolina (Cronin et al, 1981).…”

Ecological Shifts along the Florida Reef Tract: The Past as a Key to the Future

“…Evidence for at least two separate sea-level peaks during MIS 5e have been documented throughout the Caribbean including south Florida (Muhs et al 1992;Precht 1993;Neumann and Hearty 1996;White, Curran, and Wilson 1998;Fruijtier, Elliott, and Schlager 2000). The local maximum sea level during MIS 5e has been calculated at ~7 m above present (Randazzo and Halley 1997;Lidz 2000a,b) and is in close correlation with the elevation of 7.5 ± 1.5 m proposed by Cronin et al (1981) for the U.S. Atlantic Coastal Plain. This also corresponds with an elevation of 6 ± 1 m measured along the north coast of Jamaica (Precht 1993).…”

Historical Evidence for Fluctuation in Levels of Hybridization

“…No radiometric dates are available directly from the Fish House clays. The climate at that time, as inferred from pollen analyses and plant remains, was warm temperate and suggestive of interglacial conditions (Woolman, 1896; see also Cronin et al, 1981). A sewage disposal facility at the Fish House site prevents further collection from this locally exposed deposit, but a number of Lea's type specimens as well as specimens from subsequent collections are housed at the Academy of Natural Sciences of Philadelphia (ANSP).…”

“…comm. ; see Cronin et al, 1981;McCartan et al, 1982). No radiometric dates are available directly from the Fish House clays.…”