Table 1: Station data for the entire survey, including coordinates and description of BPBASE

During GANOVEX VI new gravity data were collected along an east-west profile in North Victoria Land south of the Drygalski Ice Tongue, extending 150 km across the Transantarctic Mountains, and comprising 21 data points. Thirty five additional data points were collected over a small area near Brimstone Peak, near the western end of the regional profile. The survey south of the Drygalski has been connected to northern gravity data (GANOVEX V) by a survey line of 12 points. All data have been terrain corrected, and are further constrained by satellite elevation (GPS) and radar ice-thickness measurements. A pronounced regional Bouguer gravity gradient decreasing to the west by approximately 3 mgal/km is superimposed over a coast-parallel belt of granitoid basement rock. West of this belt the local gravity fields become mote variable. Over Beta Peak (Ferrar dolerite) a 50 mgal spike is obser- ved. Within this area, the Ferrar sills are exposed at the surface. West of Brimstone Peak (Ferrar/Kirk patrick sequences), a smooth regional gradient appears to reassert itself. We interpret the initial gradient east (oceanward) of the break-in-slope to be representative of the crust/mantle boundary within the study area. We interpret the initial break-in-slope and the apparent flattening of the regional gradient to be an effect of the N-S trending zone of dense Ferrar sills and associated deep crusttil fractionate replacing less dense basement. We attribute the variability of the local field to be the product of sub-glacial density contrasts that cannot be removed. The regional gravity gradient of the profile is steeper than that observed to the north (Mt. Melbourne quadrangle) and shallower than that reported to the south (McMurdo Sound). The absolute values of the coastal points of origin south of the Drygalski and within the Mt. Melbourne quadrangle differ by 60 to 100 mgal. In addition, topographic relief within the regional transect area is subdued relative to the Transantarctic Mountains to the north and south. We speculate that the root structure of the Transantarctic Mountains undergoes a change somewhere between the Mt. Melbourne quadrangle and the region south of the Drygalski Ice Tongue.

Trace element content and coordinates for factors at DSDP Hole 72-516F

This study involves samples of Santonian to Eocene age (Cores 516F-125 to 516F-38) taken from the Rio Grande Rise in the South Atlantic Ocean. These samples are from DSDP Site 516 occupied during Leg 72 of the Glomar Challenger (details given in site chapter, Site 516, this volume). Only Santonian to Paleocene cores have been well sampled, and analyses of the Eocene samples are preliminary results. Results of the trace element analyses (Mg, Sr, Mn, Ni, Fe, Na, K) of the carbonate fraction and CaCO3 percentage for each sample can be found in Renard and others (1983). Whole geochemical data are treated by the statistical method of correspondence analysis. Oxygen and carbon isotopic ratios measured on samples close to the Cretaceous/Tertiary boundary are not used in this study.

Integrated values of heterotrophic picoplankton and primary production (euphotic zone) in the Antarctic polar frontal region during POLARSTERN cruises ANT-XIII/2 and ANT-XVI/3

We assessed relationships between phytoplankton standing stock, measured as chlorophyll a (Chl a), primary production (PP), and heterotrophic picoplankton production (HPP), in the epipelagic zone (0-100 m) as well as in the mesopelagic zone (100-1,000 m) in the polar frontal zone of the Atlantic sector of the Southern Ocean in austral summer (late December to January) and fall (March to early May). Integrated epipelagic HPP was positively correlated to integrated PP in summer (data for fall are not available) but not to integrated Chl a. However, integrated mesopelagic HPP was positively correlated to Chl a in summer as well as fall. The mesopelagic fraction of HPP as a percentage of total HPP was also positively correlated to Chl a, whereas the epipelagic fraction of HPP was negatively correlated to it. These results indicate that with increasing phytoplankton standing stock, constituted mainly of highly silicified diatoms, the focus of its consumption by heterotrophic picoplankton shifts from epipelagic to mesopelagic waters. With a growth efficiency of 30%, our HPP data indicate that in both the epipelagic and mesopelagic zone heterotrophic picoplankton consume 20% of PP. Mesopelagic heterotrophic picoplankton consumed around 80% of the sinking flux, measured from depletion of 234Th, which is a lower fraction than that reported from the central and subarctic Pacific. Our analysis indicates that it is important to include mesopelagic HPP in comprehensive assessments of the microbial consumption of PP, phytoplankton biomass, and particulate organic matter in cold oceanic systems with high rates of export production.