The Phanerozoic Record of Global Sea-level Change
Chiu, Wei-Yi
Abstract
Developments in seismic stratigraphy during 1960s and 1970s led to the recognition that primary seismic reflections parallel strata surface and unconformity and their correlative conformities represent primary units with chronostratigraphic significance. Vailet al.used stratal geometries and patterns of onlap, downlap, truncation, and basinward shifts of coastal onlap to interpret sea level histories along various continental margins.
Advances in sequence stratigraphy and the development of depositional models have helped explain the origin of genetically related sedimentary packages during sea level cycles. The sequence stratigraphic depositional models, together with detailed paleontological data and specific physical surface, can be used to identify sequence in land-based and offshore marine section. In this way, sea level changes can be documented in diverse areas that are within the public domain.
Fluctuation in global sea level result from changes in the volume of water in the ocean or the volume of ocean basin. Sea level change has influenced phytoplankton evolution, ocean chemistry, and the loci of carbonate, organic carbon, and siliciclastic sediment burial.
Miller et al.review Phanerozoic sea level changes (543million years ago to present) on various times scales and present a new sea level record for the past 100 million years. Long-term sea level peaked at 100กำ50 meter during the Cretaceous, implying that ocean-crust production rates were much lower than previously inferred. Sea level mirrors oxygen isotope variations, reflecting ice-volume change on the 104-106-year scale, but a link between oxygen isotope and sea level on the 107-year scale must be due to temperature changes that we attribute to tectonically controlled carbon dioxide variations.
Reference
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Miller, K. G., Kominz, M. A., Browning, J. V., Wright, J. D., Mountain, G. S., Katz, M. E., Sugarman, P. J., Cramer, B. S., Christie-Blick, N., and Pekar, S. F. (2005) The Phanerozoic record of global sea-level change. Science, 310, 1293-1298.