Marine oxygenated

However, the Slowey et al. (1995) work on shallower carbonate bank sediments (off of the Bahamas) was successful and led to the dating of a number of important events in the marine oxygen isotope record (including the timing of the Last Interglacial (Slowey et al. 1996), Termination II (Henderson and Slowey 2000) and portions of the Penultimate Interglacial (Slowey et al. 1996, Robinson et al. 2002). The shallower depths obviate the most serious of the initial thorium problems encountered in the Nicaragua Rise work. 

Chlorophyll a (Chi a) functions as the primary light harvesting pigment in marine oxygenic phototrophs. Even though the C Chl a ratio of photoautotrophic cells varies considerably as a function of environmental conditions and growth rate (Laws et al., 1983), measurements of Chi a have been used extensively to estimate the biomass of photoautotrophic microorganisms in the sea. 

Of special geological interest is the isotopic analyses of coeval carbonate-phosphate pairs (Wenzel et al. 2000), which helps to distinguish primary marine signals from secondary alteration effects and sheds light on the causes for 5 0 variations of fossil ocean water. Wenzel et al. (2000) compared Silurian cal-citic brachiopods with phosphatic brachiopods and conodonts from identical stratigraphic horizons. They showed that primary marine oxygen isotope compositions are better preserved in conodonts than in brachiopod shell apatite and suggested that conodonts record paleotemperature and ratios of Silurian sea water. 

History of Marine Oxygen Isotope Measurements and Sea Level 4.2 Comparison of Direct Sea-level and Benthic Foram Records. 4.3 Or O-based Sea-level Records... 

History of Marine Oxygen Isotope Measurements and Sea Level... 

Recent years have seen the development of foram Mg/Ca thermometry (Nurnberg, 1995 Nurnberg et al., 1996 Lea et al., 1999 Elderfield and Ganssen, 2000 Chapter 6.14) and its use to separate the seawater and temperature components of the marine oxygen isotope record (Elderfield and Ganssen, 2000 Lea et al., 2000, 2002). 

Figure 9 Benthic marine oxygen isotope records (left diagrams) from the Carnegie Ridge (a) (Pacific Shackleton et aL, 1983) and the Ceara Rise (b) (Atlantic Curry and Oppo, 1997) and their separation into sea-level components (middle diagrams) and temperature components (right diagrams) (after Cutler et aL, 2003).

Figure 10 Comparisons of the direct sea-level record (thick gray trace from Figures 5-8), the sea-level record from the top-center panel of Figure 9 (finely dashed line between 130 kyr and present Cutler et al., 2003), a sea-level record based on subtraction of the temperature component (using Mg/Ca thermometry) from a planktonic marine oxygen isotope record (solid black trace Lea et al., 2002), and a sea-level record based on the separation of oxygen isotope components from the record of variations in atmospheric O2...

Fairbanks R. G. and Matthews R. K. (1978) The marine oxygen isotope record in Pleistocene coral, Barbados, West Indies. Quat. Res. 10, 181 — 196. 

Mix A. C. (1992) The marine oxygen isotope record constraints on timing and extent of ice-growth events (120-65 ka). In The Last Interglacial Transition in North America, Geological Society of America Special Paper (eds. P. U. Clark and P. D. Lea). GSA, Boulder, Co. vol. 270, pp. 19-30. 

Figure 5. Th-U ages of calcite speleothems from Spannagel Cave (arrows) superimposed on the marine oxygen isotope curve (SPECMAP) to facilitate correlation with the marine isotope stages (MIS). Two Spannagel samples yielded dates > 350 kyr.

Howard, W.R., 1999, The Marine Record of the MIS 11 Oscillation. In Poore, R. Z., Burckle, L., Droxler, A., McNulty, W.E., Marine Oxygen Isotope Stage 11 and associated Terrestial Records Workshop Report. uses Open File Report 99-312. p. 31-34. 

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