John, Cedric M. et al. (2004): delta (super 18) O and Marion Plateau backstripping; combining two approaches to constrain late middle Miocene eustatic amplitude

Leg/Site/Hole:
ODP 194
ODP 194 1192
ODP 194 1193
ODP 194 1194
ODP 194 1195
Identifier:
2004-070980
georefid

10.1130/G20580.1
doi

Creator:
John, Cedric M.
Universitaet Potsdam, Institut fuer Geowissenschaften, Potsdam, Federal Republic of Germany
author

Karner, Garry D.
Lamont-Doherty Earth Observatory, United States
author

Mutti, Maria
author

Identification:
delta (super 18) O and Marion Plateau backstripping; combining two approaches to constrain late middle Miocene eustatic amplitude
2004
Geology (Boulder)
Geological Society of America (GSA), Boulder, CO, United States
32
9
829-832
delta (super 18) O (sub benthic) values from Leg 194 Ocean Drilling Program Sites 1192 and 1195 (drilled on the Marion Plateau) were combined with deep-sea values to reconstruct the magnitude range of the late middle Miocene sea-level fall (13.6-11.4 Ma). In parallel, an estimate for the late middle Miocene sea-level fall was calculated from the stratigraphic relationship identified during Leg 194 and the structural relief of carbonate platforms that form the Marion Plateau. Corrections for thermal subsidence induced by Late Cretaceous rifting, flexural sediment loading, and sediment compaction were taken into account. The response of the lithosphere to sediment loading was considered for a range of effective elastic thicknesses (10<T (sub e) <40 km). By overlapping the sea-level range of both the deep-sea isotopes and the results from the backstripping analysis, we demonstrate that the amplitude of the late middle Miocene sea-level fall was 45-68 m (56.5+ or -11.5 m). Including an estimate for sea-level variation using the delta (super 18) O (sub benthic) results from the subtropical Marion Plateau, the range of sea-level fall is tightly constrained between 45 and 55 m (50.0+ or -5.0 m). This result is the first precise quantitative estimate for the amplitude of the late middle Miocene eustatic fall that sidesteps the errors inherent in using benthic foraminifera assemblages to predict paleo-water depth. The estimate also includes an error analysis for the flexural response of the lithosphere to both water and sediment loads. Our result implies that the extent of ice buildup in the Miocene was larger than previously estimated, and conversely that the amount of cooling associated with this event was less important.
English
Serial
Coverage:Geographic coordinates:
North:-20.1400
West:151.4700East: 152.4100
South:-20.3500

Stratigraphy; Isotope geochemistry; ancient ice ages; Anomalinidae; Australasia; Australia; backstripping; benthic taxa; biochemistry; carbonate platforms; Cassidulinacea; Cenozoic; Cibicidoides; Coral Sea; deep-sea environment; eustacy; flexure; Foraminifera; geochemistry; geophysical methods; geophysical profiles; geophysical surveys; glacial environment; glaciomarine environment; Invertebrata; isotope ratios; isotopes; Leg 194; lithosphere; loading; marine environment; Marion Plateau; mechanical properties; microfossils; middle Miocene; Miocene; Neogene; O-18/O-16; Ocean Drilling Program; oceanic lithosphere; ODP Site 1192; ODP Site 1193; ODP Site 1194; ODP Site 1195; oxygen; Pacific Ocean; paleobathymetry; paleoecology; plateaus; Protista; Queensland Australia; reflection methods; Rotaliina; sea-level changes; seismic methods; seismic profiles; South Pacific; Southwest Pacific; stable isotopes; surveys; Tertiary; West Pacific;

.