Radiochemistry at DSDP Leg 54 and 70 Holes

Use of the hydraulic piston corer during DSDP Leg 70 in the Galapagos mounds area allowed recovery of an undisturbed sedimentary sequence down to the basement. It thus became possible to establish the chronology of different events. Several holes on and off the mounds were studied, using uranium series disequilibrium methods of age determination and oxygen isotope stratigraphy. The following sequence was thereby established: 1) From 600,000 to 300,000 years ago there was normal pelagic sedimentation, with an injection of uranium-rich solution, probably of hydrothermal origin, between 400,000 and 300,000 years ago. 2) From 300,000 to 90,000 years ago, nontronitic clay formed, replacing a pre-existing sediment. 3) From 60,000 to 20,000 years ago, manganese oxide deposits formed, probably also replacing pre-existing sediments. 4) About 19,000 years ago there occurred a uranium injection from seawater, attributed to the end of the hydrothermal circulation. In some holes, especially Hole 424, Leg 54, younger manganese oxides have been found, indicating that some mounds may be presently active.

Industrial uses of isotopes, chemical reaction mechanisms and kinetics, and radiochemistry : a selected list of references /

This bibliography contains 417 annotated references on uses of isotopes in industry and in chemical reaction mechanisms and kinetics. The references were taken from the 1957-1958 open literature. Also included are a list of journals from which the references were selected, an author index, an isotope index, and a graphical depiction of typical applications.

Application of radiochemistry techniques in food processing research : radioisotopic tracer techniques in evaluation and improvement of industry practices for removal of pesticide residues from foods : annual report no. 4 /

"D-1548."

Application of radiochemistry in food processing research. annual report /

"TID-4500."

Application of radiochemistry techniques in food processing research. progress report /

"TID-4500."

Application of radiochemistry techniques in food processing research : radioisotopic tracer techniques in evaluation and improvement of industry practices for removal of pesticide residues from foods : annual report /

"TID-4500."