(Table 1) 87Sr/86Sr and Sr/Ca ratios in foraminiferal calcite from DSDP Holes 3-21 and 39-357

The 87Sr/86Sr ratio of ancient seawater, as recorded in marine carbonates, is an important tracer of long-term variations in ocean chemistry (Burke et al., 1982, doi:10.1130/0091-7613(1982)10<516:VOSSTP>2.0.CO;2; Peterman et al., 1970, doi:10.1016/0016-7037(70)90154-7; Dasch and Biscaye, 1971, doi:10.1016/0012-821X(71)90164-6; Veizer and Compston, 1974, doi:10.1016/0016-7037(74)90099-4; Brass, 1976, doi:10.1016/0016-7037(76)90025-9). However, the Sr isotope balance of the oceans has been difficult to constrain; consequently, attempts to evaluate the temporal 87Sr/86Sr changes have been largely qualitative. To constrain the causes of these variations we have measured 87Sr/86Sr ratios in carefully cleaned unrecrystallized foraminifera from DSDP sites 21 and 357. The data presented here have been quantitatively modelled taking advantage of recent advances in understanding of the Sr geochemical cycle. They suggest that whereas hydrothermal fluxes and carbonate recycling are of major importance in defining the marine 87Sr/86Sr ratio, the major control over its variations through the Cenozoic has been changes in the isotope composition of Sr derived from the weathering of silicate rocks.

(Table 1) Magnetic viscosity coefficient, VRM and NRM of DSDP Hole 6-57

THE magnetic properties of the basalts which form layer 2 of the oceanic lithosphere are important because of their relevance to the hypothesis (Vine and Matthews, 1963, doi:10.1038/199947a0) of seafloor spreading. Most studies of these magnetic properties have been carried out on basalts obtained from dredge hauls taken predominantly from ocean ridge systems and fracture zones. These constitute special areas of the oceanic crust where the sediment cover is negligible. It is of interest to compare the magnetic properties of the dredged basalts with samples recovered from holes drilled through the overlying sediments into the basaltic layer at places distant from ridge axes. Samples obtained from the abandoned Mohole project and, more recently, from the Deep Sea Drilling Project (DSDP) possessed magnetic properties similar to those of dredged basalts (Cox and Doell, 1962, doi:10.1029/JZ067i010p03997; Lowrie et al., 1973, doi:10.1016/0012-821X(73)90198-2). Here I describe highly unstable magnetic characteristics found in basalts from DSDP hole 57.

(Table 1, page 437) Chemical composition of manganese encrusted Rhabdammina tubes in Eastern Mediterranean off Cyprus

Study of cores taken from the north-eastern Mediterranean during cruise 4/72 of the RRV Shackleton, using a Lehigh 4-inch hydroplastic gravity corer and containing layered organic structures encrusted with either manganese or iron minerals.