(Tables 1,2) Site characteristics and phenotypic attributes of King Penguins (Aptenodytes patagonicus) on Possession Island

In colonial species, it is often assumed that locations in the center of the colony are of highest quality and provide highest breeding success. We tested this prediction, known as the "central-periphery model," in a King Penguin colony in the subantarctic Crozet Archipelago. Breeding activity and survival of 150 penguins, fitted with transponder tags, were monitored over an entire breeding season. Among these 150 birds, 50 bred on the slope at the upper periphery of the colony, where the rates of predation and parasitism by ticks were high. Fifty birds bred in the center of the colony, where rates of predation and tick parasitism were low, and 50 bred at the lower end of the colony, where the rate of tick parasitism was low but predation and flooding were important risks. We predicted that the center of the colony should provide the safest breeding place and consequently be characterized by the highest breeding success and be used by the highest-quality individuals. Yet we found that penguins breeding in the center of the colony had the same breeding success as those at both peripheral locations. In addition, penguins breeding on the upper slope had a higher survival rate than penguins breeding at the center or bottom of the slope and were likely of higher quality. Our study does not support the central-periphery model and emphasizes the complexity behind the relationships among breeding site, breeding success, and individual quality.

(Table 1) Geochemistry of glass shards at DSDP Leg 84 Holes

Three Leg 84 sites provided a good record of explosive volcanism onshore (in Central America). Ash layers and many ashy pods are interbedded in Recent to Oligocene strata. Evidence of the main periods of activity was noted in Recent to upper Pleistocene, Pliocene-Pleistocene, lower Pliocene to upper Miocene, lower Miocene, and upper Oligocene. Noticeable traces of older volcanism were found in upper Eocene strata. The chemical analyses of glass shards show a dacitic to rhyolitic composition with a low to moderate calc-alkalinity. A preliminary distinction of samples in three geochemical groups according to their K2O/SiO2 contents is done to test a magmatic evolution. Comparisons are made with Leg 67 and on-land data.

Organic geochemistry and Rock-Eval pyrolysis at DSDP Leg 79 and 41 Holes

Cenozoic and Mesozoic sediments ranging in age from Pleistocene to Early Jurassic/late Triassic were recovered on DSDP Leg 79, off Morocco at Sites 544 to 547 in front of the Mazagan Plateau. The main zone of oil genesis should be reached at Site 547 within the Jurassic section. Organic material of marine origin with good petroleum potential characterizes the late Eocene slumps of Site 547 and originates from reworked organic matter of Cretaceous origin. Organic enrichment also occurs at Site 545 during the middle to late Albian period. Since the organic matter appears to be autochthonous, reducing environments of deposition are inferred. In the other Cretaceous deposits, variably altered organic matter of the same origin predominates. Finally, a transect including Site 370 off the Agadir Canyon, is studied: detrital organic matter and reducing environments of deposition were more developed during Albian time for Site 370 than for Site 545.

Mineralogy and geochemistry of volcanic ash at Japan Trench from DSDP Legs 87 and 57

Volcanogenic sediments were obtained from Site 584, located on the midslope of the Japan Trench. Occurrences of volcanic ash in the diatomaceous mudstones increase within sediments dated 6-3 Ma. The frequency pattern and the sediment accumulation rate obtained at Site 584 are similar to those of Site 440 and to those of Sites 438 and 439, located on the upper slope basin. Explosive volcanism increased during the Pliocene and late Miocene in relation to the intrusion of Tertiary granites and uplift of the Tohoku Arc (northeastern Japan Arc). Hygromagmaphile element concentration shows that the glass does not belong to a unique series, and a comparison with Nankai Trough data distinguishes at least two different evolutionary lines.