Stomach content and parasite characteristics of M. scorpius from Frobisher Bay, Baffin Island

Shorthorn sculpin (Myoxocephalus scorpius) from Frobisher Bay, Baffin Island, is a slow growing long-lived species. A wide range of diet items were present in the stomachs of the shorthorn sculpins sampled but 2-3 diet items (amphipod species) comprised 99.5 % of total food consumed. These amphipods were present in the stomachs in similar proportions among all age classes of shorthorn sculpin. Several new host records for parasites were reported and mean numbers of parasite species increased with shorthorn sculpin age. The increased diversity of parasite species and higher d15N values in older/larger individuals suggest that their diets were more diverse and the prey items consumed had higher d15N values. By contrast, the value of d13C in dominant diet items masked the d13C values of minor diet items. We conclude that parasites and stable isotope values provide complementary data on feeding patterns of the shorthorn sculpin. The ubiquitous marine acanthocephalan, Echinorhynchus gadi, was found at high prevalences (87-100 %) and mean intensities (28-35), and were localized in the midgut. In contrast to other studies on acanthocephalans, E. gadi did not influence fish condition as measured by condition factor, liver somatic and gonado-somatic indices.

Grain shape and mineralogy of loess on New Zealands South Island

Infilled fissures are described from the interface between two loess deposits on Banks Peninsula, South Island, New Zealand. Both loesses differ from the other loesses by having a solifluction deposit at their base consisting of angular basalt fragments of the same angularity as fresh frost shattered basalt mixed with the loess. Typically, the fissures are narrow and up to 160 cm deep while the infilling of the overlying loess shows no obvious structure. They occur mainly at higher elevations on south (poleward) facing slopes, and the host loess forms a fragipan of high density. They are most readily explained as being seasonal frost fissures or more probably ice-wedge casts, which would have required either permafrost or deep seasonal frost for their formation. If permafrost had existed, this would imply a cooling of the mean annual temperatures by at least 16 to 18°C.

Chemical composition of phosphorites and host sediments

Paleotemperature curves were drawn from oxygen-isotope ratios in CaCO3 of planktonic foraminiferal tests and by the micropaleontological method using quantitative relationships of their species. Two series of curves yield similar results. These data confirm that isotope composition of oxygen reflects primarily temperature, and not isotope composition in ocean water. Temperature of the upper layer of ocean water increased from north to south both during the last two glaciations and in the interglacials. All three sediment cores collected from different latitudes show approximately the same amplitudes of fluctuation of mean annual temperature during times of their accumulation, as determined independently by different methods; these amplitudes are estimated as 5-7°C.

(Table T1) Geochemical composition of xenoliths and host rocks from ODP Hole 193-1188A and dredge haul MD-138, PACMANUS field

A number of intensely altered, dark xenoliths with palimpsest quench textures were recorded within altered dacitic host rocks at Site 1189 (Roman Ruins, PACMANUS) during Ocean Drilling Program (ODP) Leg 193. Several of these displayed puzzling marginal fringes, apparently of altered plagioclase with variolitic texture, protruding into adjacent host rocks. Despite their alteration, the xenoliths were interpreted as fragments of rapidly chilled, possibly olivine-bearing basalts incorporated into the dacitic magmas either within the crustal plumbing system or during eruption at the seafloor (figures F15, F16, F17, F42, and F43 in Shipboard Scientific Party, 2002, doi:10.2973/odp.proc.ir.193.104.2002). An additional example of formerly spinifex-textured xenolith, the first from Site 1188 (Snowcap) and the first from the upper cristobalite-bearing zone of alteration, has been revealed by postcruise studies. Furthermore, a pristine sample of the parent lithology has been found within a dredge haul (MD-138, Binatang-2000 Cruise of Franklin; 3°43.60'S, 151°40.35'E, 1688 meters below sea level) from the Satanic Mills hydrothermal field at PACMANUS, near ODP Site 1191. The purpose of this report is to document these discoveries and thereby to confirm and build on shipboard interpretations. To my knowledge, similar xenoliths have never before been found in modern island arc or backarc volcanic sequences. Spinifex textures are most common in Archean komatiites, some of which are bimodally associated with calc-alkaline felsic volcanic rocks.

Growth rates of Fe-Mn nodules and age and sedimentation rates of host sediments from the Southeast Pacific

Growth rates of nine ferromanganese nodules collected from the Southeast Pacific were estimated using the alpha radiogpaphic technigue. Growth rates range from 1 to 16 mm per million years. In three nodules measurements were made on two opposite sides; two of them showed no growth in one of measured directions during the last 300 ky, whereas in the third nodule growth rates on the opposite sides differ by factor 2. Average sedimentation rate of deposits underlying the nodules estimated by the radiocarbon and excess 230Th methods, were 4 mm/1000 years with rather minor variations. Difference between sedimentation rates and nodule growth rates is caused by activity of benthic fauna, as suggested by inversion of radiocarbon dates with depth.