Stable isotope record of Cibicidoides wuellerstorfi from Pleistocene sediments of DSDP Site 86-502 in the Caribbean Sea

Variations in the stable isotopic composition of benthic foraminifera from Deep-Sea Drilling Project (DSDP) site 502B in the Caribbean Sea are used to reconstruct Atlantic intermediate water circulation variability over the last 1.2 m.y. Comparison of this record with other North Atlantic benthic isotope records indicates that Atlantic intermediate water circulation was relatively enhanced during glacial maxima when North Atlantic deep water (NADW) production was reduced. However, a simple, compensatory relationship between intermediate and deepwater circulation is not apparent. Geochemical models have shown that such changes in ocean circulation can affect atmospheric CO2 levels by changing vertical nutrient and alkalinity profiles. The Delta delta13C difference between Caribbean site 502B and deep equatorial Pacific site 677 is highly coherent and in phase with ice volume. Like the delta18O record, there is an increase in amplitude (40%) and a large increase in 100 kyr power after 0.7 Ma. The 1.2? Delta delta13C amplitude scales to 70 ppm V in atmospheric CO2 using Boyle's (1986) box model result. The implied increase in CO2 amplitude after 0.7 Ma may suggest a positive feedback role in effecting the higher-amplitude climatic fluctuations which characterize the last 0.7 m.y.

Sedimentation rates calculated on surface sediment samples from different site of the Atlantic and Pacific Oceans (Table 1)

Radiocarbon ages on CaCO3 from deep-sea cores offer constraints on the nature of the CaCO3 dissolution process. The idea is that the toll taken by dissolution on grains within the core top bioturbation zone should be in proportion to their time of residence in this zone. If so, dissolution would shift the mass distribution in favor of younger grains, thereby reducing the mean radiocarbon age for the grain ensemble. We have searched in vain for evidence supporting the existence of such an age reduction. Instead, we find that for water depths of more than 4 km in the tropical Pacific the radiocarbon age increases with the extent of dissolution. We can find no satisfactory steady state explanation and are forced to conclude that this increase must be the result of chemical erosion. The idea is that during the Holocene the rate of dissolution of CaCO3 has exceeded the rain rate of CaCO3. In this circumstance, bioturbation exhumes CaCO3 from the underlying glacial sediment and mixes it with CaCO3 raining from the sea surface.

UM Men's Swimming Team, 1963UM Swimming

Front Row, Left to Right: Paul A. Attar, Michael G. Reissing, Steven D. Thrasher, captain John H. Dumont, Stanley C. (Pete) Cox, Richard F. Nelson.

Second Row: Warren G. Uhler, Roy D. Burry, John Candler, Thomas Burns, Andrew Paterson, Patrick Faul, Jon W. Lundin.,

Back Row: swimming coach Gus Stager, Stephen Selander, Frederick R. Damm, Dennis J. Fitzgerald, Richard Abineri, Jerry Traver, diving coach Dick Kimball.

A battery-operated air sampler for remote areas /

"Monitoring Systems Research and Development Division, Environmental Monitoring and Support Laboratory."

A double anniversary sermon of the thirty year's episcopate of Bishop Samuel David Ferguson, June 24, 1885-1915 : fifty years of his ministry, December 31, 1865-1915, preached in St. Mark's Church, June 27, 1915 /

Cover title.

The prairie president; living through the years with Lincoln, 1809-1861,

Mode of access: Internet.

The Fifty-fifth Regiment of the Massachusetts Volunteer Infantry, colord [sic], June 1863-September 1865 /

"Third edition, revized, with additions and in simplified spelling, February, 1919."

Gypsum and other sulfur materials for soil conditioning /

Mode of access: Internet.

Sonata, no. 4, D minor, op. 61.

Mode of access: Internet.

Organ works /

Three preludes and fugues, op. 37 -- Six sonatas, op. 65.

Systems studies of automated highway systems: appendix I - conceptual automated highway system designs. Final report.

Federal Highway Administration, Traffic Systems Division, Washington, D.C.

An evaluation of the bumper standard - as modified in 1982. Technical report.

Mode of access: Internet.

Highway design and operations standards affected by driver characteristics. Volume II: final technical report.

Federal Highway Administration, Office of Safety and Traffic Operations Research and Development, Washington, D.C.

Don Carlo : opera in cinque atti di G. Méry e C. du Locle /

Mode of access: Internet.