2005 Salt Lake City Annual Meeting (October 16–19, 2005)

Paper No. 1
Presentation Time: 1:30 PM


MILLER, Kenneth G.1, KOMINZ, Michelle A.2, BROWNING, James V.1, WRIGHT, James D.1, MOUNTAIN, Gregory S.3, KATZ, Miriam E.1, SUGARMAN, Peter J.4, CRAMER, Benjamin S.1, CHRISTIE BLICK, Nicholas5 and PEKAR, Stephen F.5, (1)Dept. of Geological Sci, Rutgers Univ, 610 Taylor Rd, Piscataway, NJ 08854, (2)Geosciences, Western Michigan Univ, Kalamazoo, MI 49008, (3)Dept. of Geological Sci, Rutgers University, 610 Taylor Rd, Piscataway, NJ 08854, (4)New Jersey Geol Survey, P.O. Box 427, Trenton, NJ 08625, (5)Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, kgm@rci.rutgers.edu

Sea-level changes have occurred throughout the Phanerozoic (past 543 my) on various geological time scales and with distinctive causes. On the 108 y scale, sea-level changes of 100's m are controlled by the assembly and dispersal of supercontinents. On the 107 y scale, changes of 100-300 m have been attributed to variations in ocean crust production, although new data question this long-held tenet. Ice-volume variations controlled sea-level changes of ~30-80 m on the 106 y scale over at least the past 100 my and changes of 30-120+ m on the 104-105 y scale for the past 2.5 my. The last deglaciation (18-6 ka) caused a rapid rise punctuated by 103 y perturbations, with global sea level rising slowly (1 mm/y) over the past 6 ky. Here, we review sea-level changes over the past 543 my and present a new sea-level record for the last 100 my. 107 y scale sea-level changes were smaller than previously inferred, with a Late Cretaceous peak of 100±50 m, implying smaller changes in seafloor spreading rates. Sea-level change has influenced evolutionary trends in phytoplankton, ocean chemistry, and the loci of carbonate, organic carbon, and siliciclastic sediment burial. It reflects global climate change through a covariance with CO2 on the 107 y scale and ice volume and CO2 on the scales of 104-106 y. Over the past 100 my, sea-level changes reflect global climate evolution from a time of ephemeral Antarctic ice sheets (100-33 Ma) through a world in which Antarctic ice sheets were large and variable (33-2.5 Ma) to a world in which both Antarctic and Northern Hemisphere ice sheets were large and variable (2.5-0 Ma).