Annotated record of the detailed examination of Mn deposits from the HILO Expedition stations

The cores and dredges described in this report were taken on the HILO Expedition in March-April 1962 by Scripps Institution of Oceanography from, the R/V Stranger. A total of 21 cores and dredges were recovered and are available at Scripps for sampling and study.

Annotated record of the detailed examination of Mn deposits from the Swedish Deep Sea Expedition

The cores and dredges described in this report were taken during the Swedish Deep Sea Expedition from July 1947 until October 1948 aboard the S/S Albatross (Boström). A total of 370 cores and trawls during this World circumnavigation.

Annotated record of the detailed examination of Mn deposits from the MUKLUK expedition in the North-East Pacific Ocean

The cores and dredges described are taken during the MUKLUK expedition of the R/V Spencer Baird in July-August 1957 by the Scripps Institute of Oceanography. A total of 31 cores and dredges were recovered and are available at Scripps Institute of Oceanography for sampling and study.

Annotated record of the detailed examination of Mn deposits from R/V Eltanin Cruise 5 stations

Cores, submarine photography and dredges described in this report were taken during the R/V Eltanin Cruise 5 in 1962 by the Department of Geology, Florida State University. Cores and dredges were recovered for 31 stations and are available at the Antarctic Research Facility, Florida State University for sampling and study.

(Table, page 351-359) Chemical composition of manganese nodules and crusts from the Pacific and Indian Ocean

Chemical and mineralogical analyses of manganese nodules from a large number of widely spaced localities in the Pacific and Indian Oceans have shown that their mineralogy and chemical composition varies both areally and with depth of formation. This is considered to result from a number of factors, important among which are: (a) their proximity to continental or volcanic sources of elements; (b) the chemical environment of deposition, including the degree of oxygenation; and (c) local factors such as the upward migration of reduced manganese in sediments from certain areas. Sub-surface nodules appear to share the chemical characteristics of their surface counterparts, especially those from volcanic areas where sub-surface sources of elements are probably important.

Annotated record of the detailed examination of Mn deposits in the Atlantic Ocean from cruises from R/V Atlantis II, R/V Knorr, R/V Melvin and R/V James M. Gilliss in 1980-1981

This report is Volume 3 of Descriptions of WHOI rock dredge samples. This series represents a major effort to catalog the rock dredge samples in the WHOI Sea Floor samples collection, and to disseminate this information throughout the scientific community. Volume 3 contains sample descriptions and station data for the dredge stations from five cruises during the period September 1978 through December 1980. The material in this and subsequent volumes of rock descriptions was largely prepared onboard ship by the participating scientists. Volume 3 was printed prior to volumes 1 and 2 because of the excellent documentation of the samples represented in this volume.

Annotated record of the detailed examination of Mn deposits from RISEPAC Expedition stations

The cores and dredges described in this report were taken on the RISEPAC Expedition from October 1961 until February 1962 by the Scripps Institution of Oceanography from the R/V Spencer F. Baird. A total of 164 cores and dredges were recovered and are available at Scripps for sampling and study.

Annotated record of the detailed examination of Mn deposits from BENTHIFACE Expedition stations

The cores described in this report were taken on the BENTHIFACE Expedition in June 1973 to July 1973 by the Scripps Institution of Oceanography from the R/V Melville. A total of 128 cores and dredges were recovered and are available at Scripps for sampling and study.

Observation of manganese nodules and crusts recovered during the CHAIN 115 cruise from Nov 1973 until June 1974 in the Atlantic Ocean

Investigations of piston cores from the Vema Channel and lower flanks of the Rio Grande Rise suggest the presence of episodic flow of deep and bottom water during the Late Pleistocene. Cores from below the present-day foraminiferal lysocline (at ~4000 m) contain an incomplete depositional record consisting of Mn nodules and encrustations, hemipelagic clay, displaced high-latitude diatoms, and poorly preserved heterogeneous microfossil assemblages. Cores from the depth range between 2900 m and 4000 m contain an essentially complete Late Pleistocene record, and consist of well-defined carbonate dissolution cycles with periodicities of ~100,000 years. Low carbonate content and increased dissolution correspond to glacial episodes, as interpreted by oxygen isotopic analysis of bulk foraminiferal assemblages. The absence of diagnostic high-latitude indicators (Antarctic diatoms) within the dissolution cyclss, however, suggests that AABW may not have extended to significantly shallower elevations on the lower flanks of the Rio Grande Rise during the Late Pleistocene. Therefore episodic AABW flow may not necessarily be the mechanism responsible for producing these cyclic events. This interpretation is also supported by the presence of an apparently complete Brunhes depositional record in the same cores, suggesting current velocities insufficient for significant erosion. Fluctuations in the properties and flow characteristics of another water mass, such as NADW, may be involved. The geologic evidence in core-top samples near the present-day AABW/NADW transition zone is consistent with either of two possible interpretations of the upper limit of AABW on the east flank of the channel. The foraminiferal lysocline, at ~4000 m, is near the top of the benthic thermocline and nepheloid layer, and may therefore correspond to the upper limit of relatively corrosive AABW. On the other hand, the carbonate compensation depth (CDD) at ~4250 m, which corresponds to the maximum gradient in the benthic thermocline, is characterized by rapid deposition of relatively fine-grained sediment. Such a zone of convergence and preferential sediment accumulation would be expected near the level of no motion in the AABW/NADW transition zone as a consequence of Ekman-layer veering of the mean velocity vector in the bottom boundary layer. It is possible that both of these interpretations are in part correct. The "level of no motion'' may in fact correspond to the CCD, while at the same time relatively corrosive water of Antarctic origin may mix with overlying NADW and therefore elevate the foraminifera] lysocline to depths above the level of no motion. Closely spaced observations of the hydrography and flow characteristics within the benthic thermocline will be required in order to use sediment parameters as more precise indicators of paleo-circulation.

Annotated record of the detailed examination of Mn deposits from R/V Atlantis Cruise 172 stations

The cores described were taken by the personnel of the Lamont-Doherty Earth Observatory (LDEO) operating as guests scientists during the R/V Atlantis Cruise 172 undertaken by the Woods Hole Oceanographic Institution from April until June 1951. A total of 35 cores were recovered and are available at Lamont-Doherty Earth Observatory for sampling and study.

Annotated record of the detailed examination of Mn deposits from R/V Atlantis Cruise 167 stations

The cores described were taken by the personnel of the Lamont-Doherty Earth Observatory (LDEO) operating as guests scientists during the R/V Atlantis Cruise 167 undertaken by the Woods Hole Oceanographic Institution in January 1951. A total of 55 cores were recovered and are available at Lamont-Doherty Earth Observatory for sampling and study.

Annotated record of the detailed examination of Mn deposits from R/V Atlantis Cruise 160 stations

The cores described were taken by the personnel of the Lamont-Doherty Earth Observatory (LDEO) operating as guests scientists during the R/V Atlantis Cruise 160 undertaken by the Woods Hole Oceanographic Institution from Januray until April 1950. A total of 23 cores were recovered and are available at Lamont-Doherty Earth Observatory for sampling and study.

Annotated record of the detailed examination of Mn deposits from VEMA 3 Expedition stations

The cores and dredges described in this report were taken during the VEMA 3 Expedition from January 1957 until June 1954 by the Lamont Geological Observatory, Columbia University from the R/V Vema. A total of 160 cores were recovered and are available at Lamont-Doherty Earth Observatory for sampling and study.