ALBERT

Description: Petrographic, mineralogic, and geochemical data are reported for lavas from two of the major shield volcanoes of the Santorini volcanic complex (Skaros and Micro Profitis Ilias), both of which were active prior to the well-known Minoan eruption with associated caldera collapse. Field work and whole-rock chemical analyses indicate four cycles of eruptive activity within the Skaros sequence and three within the Micro Profitis Ilias (M P1) sequence. SiO2 and LIL-element contents decrease from the base to the top of all cycles except for the uppermost cycle of Skaros. Chemical variations within cycles are interpreted to result from eruption from compositionally and thermally zoned magma chambers. Major oxide data and the results of least-squares, mass balance modeling indicate that fractional crystallization played an important role in the development of the observed chemical variations. However, observed systematic variations in groundmass compositions within each cycle, observed irregular variations in total phenocryst content and the results of density calculations require that generation of the chemical zonation did not involve crystal settling but reflects unstable density stratification, probably resulting from sidewall crystallization. Some of the primitive lavas erupted on Santorini preserve phenocryst and xenocryst evidence for a stage of high-pressure fractional crystallization (involving removal of olivine, clinopyroxene, orthopyroxene, and Cr-spinel). Trace element data combined with petrographic data (i.e. the occurrence of abundant phenocrysts with resorption textures) is taken as evidence that magma mixing was also important in the development of cyclic variations. Most basaltic andesites from Skaros appear to be hybrids derived by mixing of basalt and andesite/dacite. Mineralogic data demonstrate that mixing was also important in the development of zonation in the chambers beneath MPI, but trace element data cannot be explained by combined fractionation and mixing alone. Specifically, incompatible, and compatible element abundances are lower than predicted if fractionation and mixing occurred and it is suggested that the anomalous trace element behaviour of especially LIL elements reflects the simultaneous operation of assimilation, for which there is support from isotopic studies. It is concluded that inter- cyclic chemical variations are explicable in terms of fractionation, mixing and assimilation. The LIL element and highly compatible element concentrations in the most primitive lavas erupted in each cycle of Skaros and MPI increase with time, indicating that mixing became more important with time.

Description: Osmotic adaption by halophilic and halotolerant bacteria is generally achieved by the accumulation or synthesis of several organic solutes. Accumulation by uptake from the medium is preferred over biosynthesis. The chemical nature of the major solute is important in determining the degree of osmotolerance of the organism. Glycine betaine accumulation confers a greater degree of osmotolerance than proline, which in turn confers more osmotolerance than glutamate accumulation. The occurrence and uptake of these solutes in a variety of eubacteria is reviewed.

Description: The cuttlefish ingests much skeleton from the crustaceans and fish it preys upon. The skeletal pieces are relatively large and their dimensions bear a close relationship to the length of the buccal mass and diameter of the oesophagus. The structures of the buccal mass are instrumental in the breakdown of prey and orientation of long pieces of skeleton to ensure their entry into the oesophagus. Many pieces of skeletal material present in the stomach contents still have attached muscles, showing that there is little, or no, external digestion. Skeletal material may be important for long-term maintenance of young Sepia in captivity.

Description: The diet of the king penguin Aptenodytes patagonicus at Marion Island was examined throughout the year by analysis of stomach samples. Fish accounted for 87% by wet mass, 75% by numbers and 69% by reconstituted mass. Their proportional importance by wet mass increased from 68% during winter to almost 100% in summer and probably reflects a real increase in their local availability. Squid comprised most of the remainder with crustaceans forming less than 1% of the diet by numbers. Prey items were generally small, the most abundant being three species of myctophid fish, Krefftichthys anderssoni, Protomyctophum tenisonì and Electrona carlsbergi, and a squid Kondakovia longimana. King penguins took both juvenile and adult Krefftichthys anderssoni and P. tenisoni, but only adult E. carlshergi. The juvenile and adult modal size classes of K. anderssoni and P. tenisoni increased from March through to February and the proportion of juvenile to adult fish increased in winter. The increase in the modal size class of the K. anderssoni/P. tenisoni complex during the year probably reflects growth of the fish, rather than movement of different populations in and out of the area exploited by king penguins. All squid consumed were probably juveniles. The modal size class of Kondakovia longimana increased from March to August, but in September to October smaller squid again formed a large proportion of the squid component of the diet. Numbers of measurable squid beaks recovered from November to February were low. This is the first time that mesopelagic myctophid fish have been shown to comprise a major component of the diet of a vertebrate predator in the Southern Ocean.

Description: Additional data from sonobuoys and the Deep Sea Drilling Project (DSDP) justify separating sound‐velocity‐depth functions and velocity gradients (in the first layer of soft marine sediments) into some geographic areas and sediment types. Based on sonobuoy and core measurements (where V is sound velocity in km/s, and h is depth in sediments in km), the following data are obtained: continental shelf basins off Sumatra and Java—V=1.484+0.710h−0.085h2; U. S. Atlantic continental rise—V=1.513+0.828h−0.138h2; deep‐sea terrigenous sediments—V=1.519+1.227h−0.473h2; and siliceous sediments of the Bering Sea— V=1.509+0.869h−0.267h2. Selected DSDP data (through leg 74) in similar areas yield: continental terrace silt–clays—V=1.505+0.712h; deep‐sea terrigenous sediments—V=1.510+1.019h; and deep‐sea siliceous sediments—V=1.533+0.761h. Computed velocity gradients from sonobuoy measurements are generally supported by the DSDP gradients. Only DSDP data give the following: hemipelagic sediments—V=1.501+1.151h; deep‐sea calcareous sediments—V=1.541+0.928h; and deep‐sea pelagic clay—V=1.526+1.046h. Where fast sediment accumulation occurs, there has not been enough time to reduce sediment pore spaces under overburden pressure; areas of slow accumulation may have relatively high sediment structural strength. Both cases have lower velocity gradients because higher porosities and consequent lower velocities persist to deeper depths.

Description: In the animal kingdom evolutionary size changes involved increasing, decreasing and stationary patterns. Planktic and benthic Foraminifera chiefly increased their size during evolution. This increase, however, did not always occur gradually, but could be interrupted by periods when the animals maintained or even decreased in size. The rate of the size increase is different for the various species examined, some benthic forms grew only 10% during the Oligocene-Pleistocene interval, while for others this figure was up to 96%. Some benthic species increased in size in certain areas, but not in others. It is not improbable that some phylogenetic trends of planktic Foraminifera representing, according to stratigraphers, the evolution of one species into another, represent in reality, from the biological point of view, specimens of the same species which changed their size and in addition some minor morphological traits which are encompassed by the normal span of intraspecific variability. A comprehensive understanding and explanation of the size change of Foraminifera needs much additional research.

Description: The acoustic backscatter of eight well‐curated ferromanganese nodules has been measured in 1 °C seawater at frequencies from 45 to 167 kHz. The nodules have diameters from 37 to 121 mm and are thought to be representative of the Cu–Ni–Co‐rich nodules from the area around 14° 40’ N, 125° 25’ W (DOMES site C). They had been collected in box cores on the Echo 1 expedition and were kept refrigerated and water soaked in air‐tight plastic bags. Acoustic backscatter variations of over 10 dB were observed while the nodule was rotated 10° to 30° about one of its principal axes. The complicated fine structure, as well as the target strength, makes it clear that nodules cannot be modeled as simple spheres.

Description: Blidingia minima var. ramifera is reported for the first time in eastern North America. It occurs in the Gulf of St. Lawrence, Nova Scotia and in Maine. In the estuary of the West and Rights Rivers (Antigonish Harbour, Nova Scotia) it is the most common intertidal alga and during its maximum growth period (June‐August) covers 75–90% of the intertidal zone for several km of shoreline at the mouth of the Rights River. In culture, spore germination and early development were typical of the taxon as described from Europe. The taxon is raised to specific status as Blidingia ramifera stat. nov. Blidingia subsalsa is confirmed from New England based on observations of spore germination in plants from Maine and Connecticut.