Planktonic foraminifera were studied at Lydden Spout, near Folkestone (southeast England, UK), the reference section of the middle Cenomanian Event 1 (MCE 1) characterized by a prominent double-peak δ13C excursion of 1 ‰ identified in different ocean basins and considered a global event. Biostratigraphic and quantitative analysis of planktonic foraminifera are correlated to the δ13C perturbation, to the positive δ18O shifts identified within MCE 1 and to the occurrence of Boreal macrofossils (the bivalves Chlamys arlesiensis and Oxytoma seminudum, and the belemnite Praectinocamax primus). Variations in abundance and species richness of planktonic foraminifera and the inferred palaeoecological preferences of taxa permit the identification of distinct palaeoenvironmental settings across MCE 1. The stratigraphic interval corresponding to MCE 1 is characterized by the absence of oligotrophic rotaliporids, and by the evolutionary appearance of meso-eutrophic dicarinellids and of Muricohedbergella portsdownensis, a cold-water species that occurs at the same level as the Boreal macrofossils. These observations indicate a palaeoceanographic scenario characterized by reduced stratification of surface waters and absence/disruption of the thermocline in a dominantly eutrophic regime during MCE 1. Evidence provided by planktonic foraminifera, Boreal macrofossils and δ18O records documented for the late Cenomanian Plenus Cold Event (PCE) at Eastbourne (UK) reveal similarities that confirm the periodic inflow of cold Boreal seawater originating in the Norwegian Sea as previously postulated to explain the occurrence of Boreal fauna in the Anglo-Paris Basin. The southerly extension of this water mass may be related to the reorganization of circulation driven by the long eccentricity cycle.

Isotopic analysis of Micropogonias furnieri otoliths were used to get insight into palaeoceanographic conditions in the Guanabara Bay and Saquarema Lagoon, Rio de Janeiro state (RJ), located on the southeastern coast of Brazil, under upwelling influence of the Cabo Frio system. Archaeological otoliths come from two Holocene shellmounds (or sambaquis): Galeão and Beirada. For the first time, radiocarbon analysis using high accuracy techniques were performed at Galeão. Age range was determined to be between 5820 and 4980 cal BP, which extends the chronology of human settlement in the Guanabara Bay. Micro-samples of the otoliths were collected sequentially from the core to the edge, to provide continuous δ18O and δ13C isotopic profiles over the lifetime of the individual fish. Derived-δ18Ooto palaeotemperature estimates vary according to seasonality, resulting in a palaeoceanographic variation between 8 to 31°C for Guanabara Bay and 8 and 28°C for the Saquarema Lagoon. Our data indicate that whitemouth croakers were captured during the Middle Holocene from the Guanabara Bay and Saguarema Lagoon and resided in cooler temperatures compared to temperatures of current conditions.

The evolution and resulting morphology of a contourite drift system in the SE Pacific oceanic basin is investigated in detail using seismic imaging and an age-calibrated borehole section. The Nazca Drift System covers an area of 204 500 km2 and stands above the abyssal basins of Peru and Chile. The drift is spread along the Nazca Ridge in water depths between 2090 and 5330 m. The Nazca Drift System was drilled at Ocean Drilling Program Site 1237. This deep-water drift overlies faulted oceanic crust and onlaps associated volcanic highs. Its thickness ranges from 104 to 375 m. The seismic sheet facies observed are associated with bottom current processes. The main lithologies are pelagic carbonates reflecting the distal position relative to South America and water depth above the carbonate compensation depth during Oligocene time. The Nazca Drift System developed under the influence of bottom currents sourced from the Circumpolar Deep Water and Pacific Central Water, and is the largest yet identified abyssal drift system of the Pacific Ocean, ranking third in all abyssal contourite drift systems globally. Subduction since late Miocene time and the excess of sediments and water associated with the Nazca Drift System may have contributed to the Andean orogeny and associated metallogenesis. The Nazca Drift System records the evolution in interactions between deep-sea currents and the eastward motion of the Nazca Plate through erosive surfaces and sediment remobilization.

This paper provides insight into the Late Ordovician to earliest Silurian evolution of sedimentary environments in the southern Holy Cross Mountains (SE Poland), which at that time were a part of the SW periphery of Baltica. The facies layout in this area was influenced by the basement block faulting, which differentiated the basin bathymetry into submarine horst and grabens, controlling facies distribution. However, the local tectonism was insufficient to fully mask the global eustatic events. Therefore, it is possible to correlate some facies changes in the Upper Ordovician and lower Llandovery sedimentary record of the southern Holy Cross Mountains with eustatic and palaeoceanographic changes reported worldwide. The most noticeable influence of eustasy on the sedimentary record in the studied area occurs at the Ordovician/Silurian boundary. It is manifested by Hirnantian regressive coarse-grained clastic sediments overlain by a post-glacial anoxic/dysoxic interval represented by the Rhuddanian transgressive black cherts and shales. It is noteworthy that the pre- and post-Hirnantian sedimentary environments in the southern Holy Cross Mountains were affected by upwelling induced by the SE trade winds.

The Toarcian Oceanic Anoxic Event (T-OAE, c. 182 Ma) represents a major perturbation of the carbon cycle marked by widespread black shale deposition. Consequently, the onset of the T-OAE has been linked to the combined effects of global warming, high productivity, basin restriction and salinity stratification. However, the processes that led to termination of the event remain elusive. Here, we present palynological data from Arctic Siberia (Russia), the Viking Corridor (offshore Norway) and the Yorkshire Coast (UK), all spanning the upper Pliensbachian – upper Toarcian stages. Rather than a ‘dinoflagellate cyst black-out’, as recorded in T-OAE strata of NW Europe, both the Arctic and Viking Corridor records show high abundance and dinoflagellate diversity throughout the T-OAE interval as calibrated by C-isotope records. Significantly, in the Arctic Sea and Viking Corridor, numerous species of the Parvocysta and Phallocysta suites make their first appearance in the lower Toarcian Falciferum Zone much earlier than in Europe, where these key dinoflagellate species appeared suddenly during the Bifrons Zone. Our results indicate migrations of Arctic dinoflagellate species, driven by relative sea-level rise in the Viking Corridor and the establishment of a S-directed circulation from the Arctic Sea into the Tethys Ocean. The results support oceanographic models, but are at odds with some interpretations based on geochemical proxies. The migration of Arctic dinoflagellate species coincides with the end of the T-OAE and marks the arrival of oxygenated, low-salinity Arctic waters, triggering a regime change from persistent euxinia to more dynamic oxygen conditions.

Pollen and organic-walled dinoflagellate cyst assemblages from core GeoB 9503-5 retrieved from the mud-belt (∼ 50 m water depth) off the Senegal River mouth have been analyzed to reconstruct short-term palaeoceanographic and palaeoenvironmental changes in subtropical NW Africa during the time interval from ca. 4200 to 1200 cal yr BP. Our study emphasizes significant coeval changes in continental and oceanic environments in and off Senegal and shows that initial dry conditions were followed by a strong and rapid increase in humidity between ca. 2900 and 2500 cal yr BP. After ca. 2500 cal yr BP, the environment slowly became drier again as indicated by slight increases in Sahelian savannah and desert elements in the pollen record. Around ca. 2200 cal yr BP, this relatively dry period ended with periodic pulses of high terrigenous contributions and strong fluctuations in fern spore and river plume dinoflagellate cyst percentages as well as in the fluxes of pollen, dinoflagellate cysts, fresh-water algae and plant cuticles, suggesting “episodic flash flood” events of the Senegal River. The driest phase developed after about 2100 cal yr BP.

Southern Ocean palaeocirculation is clearly related to the formation of a continental ice sheet on Antarctica and the opening of gateways between Antarctica and the Australian and South American continents. Palaeoenvironmental proxy records from Southern Ocean sediment cores suggest ice growth on Antarctica beginning by at least 40 million years (Ma) ago, and the opening of Tasmania–Antarctic and Drake Passages to deep-water flow around 34 and 31 ± 2 Ma, respectively. So, the Eocene/Oligocene transition appears to mark the initiation of the Antarctic Circumpolar Current and thus the onset of thermal isolation of Antarctica with a first major ice volume growth on East Antarctic. There is no evidence for a significant cooling of the deep ocean associated with this rapid (< 350 000 years) continental ice build-up. After a long phase with frequent ice sheets growing and decaying, in the middle Miocene at about 14 Ma, a re-establishment of an ice sheet on East Antarctica and the Pacific margin of West Antarctica was associated with an increased southern bottom water formation, and a slight cooling of the deep ocean, but with no permanent drop in atmospheric pCO2. During the late Pleistocene on orbital time scales a temporal correlation between changes in atmospheric pCO2 and proxy records of deep ocean temperatures, continental ice volume, sea ice extension, and deep-water nutrient contents is documented. I discuss hypotheses that call for a dominant control of glacial to interglacial atmospheric pCO2 variations by Southern Ocean circulation dynamics. Millennial to centennial climate variability is a global feature, but there is contrasting evidence from various palaeoclimate archives that indicate both interhemispheric synchrony and asynchrony. The role of the Southern Ocean, however, in triggering or modulating climate variability on these time scales only recently received some attention and is not yet adequately investigated.

Two gravity cores, Gebra-1 and Gebra-2 from the central and eastern basins of Bransfield Strait, West Antarctica, consist mainly of hemipelagic, laminated muds with black layers rich in sand-sized volcanic ash. Micropalaeontological (diatoms and radiolarians) and geochemical (organic and inorganic) analyses, together with radiometric dating (U/Th, 14C and 210Pb) have been performed on both cores. AMS analyses on Total Organic Carbon yielded a 14C-age older than expected, 2810 yr BP for the core top of Gebra-1 and 2596 yr BP for Gebra-2. The downcore pattern of ages indicates a sedimentation rate of 130 cm kyr1 for Gebra-1 and 160 cm kyr1 for Gebra-2 210Pb anomalies suggest the core top of Gebra-1 is present-day sediment. The diatom and radiolarian assemblages are related to the sequence of neoglacial events over the last three millennia. The recent significant reduction in Chaetoceros resting spores is interpreted as a reduction in palaeoproductivity. The progressive increase in sea-ice taxa for the last three millennia may indicate a cooling trend. Greater sea-ice coverage during the coldest neoglacial events in the Bransfield Basin, as well as in the Weddell Sea and Bellingshausen Sea, is documented by increases in sea-ice taxa and reductions in Thalassiosira antarctica/ T. scotia resting spores, Fragilariopsis kerguelensis, the Lithomelissa group and the “circumpolar” group of radiolarians. For these periods, we postulate a restricted communication between the Weddell Sea, Bellingshausen Sea and Bransfield basin. The millenial-scale changes are overprinted by a high frequency cyclicity at about 200–300 yrs, which might be related to the 200–yrs solar cycle.

Foraminiferal studies have been used in palaeo-environmental reconstructions of the marine Cretaceous succession (upper Aptian to Maastrichtian) of the Sergipe Basin, in northeastern Brazil. The foraminiferal assemblages show broadly three types of response to changes in environment: (1) variations in morphotypes of the taxa present; (2) changes in specific and generic diversity; and (3) changes in relative abundance.

Twelve palaeocommunities, characterised by the relative dominance of the major foraminiferal groups, can be recognised in the succession. Their palaeoenvironmental distribution is proposed as a model with reference to the Sergipe Cretaceous sequence.

An intimate relationship is inferred among foraminiferal association distribution patterns, trophic structures (community feeding strategy, dwelling habits, substrate niche patterns) and water-mass conditions (depth-related in part). It is suggested that the distribution patterns may be a direct response of the functional adaptive morphology of the foraminiferal tests to individual characteristics of behavioural structure (preferential dwelling microhabitat and trophic strategy versus environment). The approach is a simple, yet very powerful tool, for the interpretation of foraminiferal palaeocommunities and palaeoceanographic research. It may also permit interpretation of palaeocommunity strategies in terms of adaptation rate and selection response (i.e. “r-selection” versus “k-selection”) to variable environmental conditions.

The Indian summer Southwest Monsoon plays an important part in influencing, and regulating, the productivity and sedimentation in the northwest Arabian Sea at the present day, by driving coastal upwelling. This leaves permanent sedimentological and geochemical records in the accumulating deep-sea sediments. Cores 722B and 724C were raised from the Owen Ridge and Oman Margin, respectively, during Leg 117 of the Ocean Drilling Program and have been subjected to geochemical analyses and α-spectrometry. A comparative core, CD17–30, situated on the adjacent Indus Fan abyssal plain, has also been studied. The chronostratigraphy of the cores has been established with δ 18O stratigraphy, giving a 350 ka climate record. Changes in the total sediment mass accumulation rates occur on glacial/interglacial time scales, with maximum fluxes occurring during glacial episodes. The high fluxes are predominantly due to wind-transported dust at the ridge and margin sites. Compositional parameters (e.g. the Ti/Al ratio) indicating the proportion of heavy minerals present within the dust, suggests that strong winds associated with the Southwest Monsoon, occur with Milankovitch periodicities, and are dominated by the precession (23 ka) frequency. The wind strength controls the proportion of heavy minerals transported to the Arabian Sea, whilst continental aridity influences the timing of deflation from the Arabian and Somalian peninsulas. Tracers of palaeoproductivity (Ba/Al) indicate strong coherence and phase with the proxy ice volume (foraminiferal δ 18O) signal, suggesting global climate parameters (ice volume, continental aridity) determine coastal productivity by influencing nutrient supply. In relation to productivity, the roles of oceanic circulation/stratification and nutrient supply through continental runoff are discussed. This study shows that the Southwest Monsoon appears to only affect the shorter period (precession cycle, 23 ka band) productivity signal. Evidence from excess 230Th suggests deep oceanic circulation (at about 2000 m depth) was more intense 110 ka BP decreasing toward 40 ka BP. By the use of these various geochemical tracers a new, and comprehensive, view of the interaction of the Monsoon and global climate with marine productivity through the late Pleistocene has been obtained.

Fossil assemblages can give quantitative estimates of palaeotemperatures, by comparison with modern biota, only in the recent geological past. Oxygen isotopic palaeotemperatures on calcareous or phosphatic fossils are potentially available for the whole Phanerozoic. Their reliability is limited by physiological effects (generally believed minor), preservation (for which criteria are available), and by uncertainty in the isotopic composition of ancient seawater. The latter is greatly affected by glaciation. In the Cenozoic, the relative contribution of ice-volume change and temperature change in producing isotopic variations can largely be resolved by analysing planktonic and benthic foraminifera in deep-sea cores. For earlier times only continental shelf deposits are available. In the Mesozoic, reasonable assumptions about ocean isotopic composition lead to palaeotemperature estimates that suggest generally higher temperatures than at present, particularly for mid- to high latitudes. This agrees with estimates based on biotic distributions. Late Palaeozoic glaciation is reflected in variable isotopic compositions in high palaeolatitude areas. In the earlier Palaeozoic, well-preserved fossils indicate either oceans enriched in 16O compared to today's or generally higher temperatures; controversy continues about the relative importance of the two effects.