Quantitative analysis of the late Cenozoic planktonic foraminiferal record from western Arabian Sea Site 722 revealed long term trends in the history of oceanography and climate. The modern western Arabian Sea surface waters are highly influenced by the monsoonal wind system. Summer upwelling, a result of southwestern winds, occurs along the coast of Somalia which produces distinct foraminiferal assemblages which are dominated by G. bulloides d'Orbigny. Consequently, variations in the distribution record of G. bulloides through time monitor the upwelling history associated with monsoonal activities. G. bulloides was a minor constituent of the foraminiferal fauna from the bottom of the hole (-14.5 Ma) until about 8.6 Ma ago. Then a rapid shift occurred toward higher values, up to 53% at 7.4 Ma. We interpret this rapid increase as a major step in the evolution of the monsoonal history. It is either the establishment of the system or at least a strong intensification of the monsoonal winds. At 5.5 Ma a significant drop of the G. bulloides relative abundance occurred which may indicate less upwelling, or alternatively other biota may have been favored in this period. From 5.0 Ma to Recent the G. bulloides record indicates that upwelling has occurred with minor fluctuations.

A long-term climatic change 4.0 x 10(5) to 3.0 x 10(5) years ago is recorded in deep-sea sediments of the Angola and Canary basins in the eastern Atlantic Ocean. In the Angola Basin (Southern Hemisphere) the climatic signal shows a transition to more humid ("interglacial") conditions in equatorial Africa, and in the Canary Basin (Northern Hemisphere) to more "glacial" oceanic conditions. This trend is confirmed by comparison with all well-documented marine and continental records from various latitudes available; in the Northern Hemisphere, in the Atlantic north of 20 degrees N, climate merged into more "glacial" conditions and in equatorial regions and in the Southern Hemisphere to more "interglacial" conditions. The data point to a more northern position of early Brunhes oceanic fronts and to an intensified atmosphere and ocean surface circulation in the Southern Hemisphere during that time, probably accompanied by a more zonal circulation in the Northern Hemisphere. The mid-Brunhes climatic change may have been forced by the orbital eccentricity cycle of 4.13 x 10(5) years.

Abstract. Slowly accumulated (<5 cm kyr '1) and rapidly accumulated (5-20 cm kyr -1) sediments have been compared to define the initiation and termnation times of the most recent sapropel (S1) in the eastern Mediterranean Sea. The Ba/A1 ratio has been employed as a more persistent index of productivity than C•g. Accelerator mass spectrometry radiocarbon dating of pelagic foraminifera indicates a maximum duration for increased Ba/A1 levels in S 1 from -9500-6000 (uncorrected radiocarbon convention years B.P.) in the rapidly accumulated sediments and -9500-5300 years B.P. in the slowly accumulated sediments. This difference is ascribed to bioturbation affecting the slower accumulated S1 sediments. In the two most rapidly accumulated S1 units, from the Adriatic and Aegean Seas, there is a "saddle" of lower values centered on 7500 years B.P. in the Corg and Ba/AI profiles, so that the visual S 1 unit appears as a doublet. Geochemical evidence indicates that this intervening period is best interpreted as an episode of increased ventilation and bottom water oxygenation during the period of sapropel accumulation.

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