Geochemistry of three cores from the East Pacific Rise

Rare-earth elements in Precambrian iron formations in Väyrylänkylä, South Puolanka area, Finland

“…The REE patterns of the sediments from the Pacific Ocean imply either that the REE were coprecipitated from sea water with ironmanganese hydroxyoxides, or that they are incorporated in the phosphatic fish debris found in all samples (Dymond et al 1973; cf. also Bender et al 1971). Thus, the apatite-rich band in Pääkkö seems to be a marine phosphorite interband.…”

The hydrothermal alteration of oceanic basalts by seawater

“…In addition, the lead isotope ratios in these heavy-metal enriched sediments resemble those of the mid-ocean ridge basalts suggesting that this component is of basement origin (Bender et al, 1971;Dasch et al, 1971;Dymond et al, 1973). The…”

“…The accumulation rates of manganese on the East Pacific Rise are two orders of magnitude faster than the average pelagic accumulation rates (Bender et al, 1971). In addition, the lead isotope ratios in these heavy-metal enriched sediments resemble those of the mid-ocean ridge basalts suggesting that this component is of basement origin (Bender et al, 1971;Dasch et al, 1971;Dymond et al, 1973).…”

Geochemistry and Origin of Eocene-Oligocene Metalliferous Sediments from the Central Equatorial Pacific: Deep Sea Drilling Project Sites 573 and 574

“…Metalliferous sediments contain these components admixed with varying proportions of ferromanganese minerals. The ferromanganese phase was initially regarded as being X-ray amorphous (Boström andPeterson, 1966, 1970;von der Borch and Rex, 1970;von der Borch et al, 1971;Bender et al, 1971), but the application of ultraslow scan X-ray diffraction (XRD) and other techniques has shown that a number of discrete mineral phases can be recognized (Dasch et al, 1971;Dymond et al, 1973;Sayles and Bischoff, 1973;Heath and Dymond, 1977;Dymond and Ek- van Andel et al, 1975). Bold numbers and dots indicate DSDP drilling sites where metalliferous sediments have been recovered.…”

“…It has been known for some time that sediments near the East Pacific Rise are strongly enriched in Fe, Mn, and other transition metals relative to normal pelagic sediments (Murray and Renard, 1891;Revelle, 1944;Boström and Peterson, 1966;Boström et al, 1969;Bender et al, 1971). It is generally accepted that the metals were leached from the basaltic crust by seawater hydrothermal systems (Corliss, 1971;Bonatti et al, 1972;Dymond et al, 1973;Piper, 1973;Bonnatti, 1975;Dymond and Veeh, 1975;Cronan, 1980;Dymond, 1981;Thompson, 1983), which subsequently deposited them as authigenic precipitates on the seafloor.…”