Annotated record of the detailed examination of Mn deposits from ARA Islas Orcadas Cruise 12 core stations

The purpose of this volume, the ninth in a series of similar publications (Goodell, 1964, 1965, 1968; Frakes 1971, 1973 ; Cassidy et al., 1977), is to continue a presentation to the research community of sediment core descriptions and attendant data of cored and otherwise obtained sediments retrieved in waters of the Southern Ocean aboard the research vessel, ARA Islas Orcadas (formerly, USNS Eltanin), as a part of the circumpolar survey begun by Eltanin in 1962 (see issue of Antarctic Journal of the United States, Vol. 8, No. 3, 1973). The data presented herein are concerned with the results of coring activities aboard cruise 1277 of Islas Orcadas, the third marine geology coring cruise of this vessel under the terms of the present United States-Argentine agreement. The core descriptions are organised as follows: 1) a brief summary of the coring objectives of the cruise, together with a discussion of core recovery; 2) a table and map of station location data for materials retrieved; 3) a table of tentative age-dates for each piston core; 4) an explanation of the laboratory procedures and descriptive criteria used in the description of the sediments, and 5) lithologic descriptions of the piston and trigger cores, and the piston and trigger core bag samples.

Age of bottom sediments from the South Atlantic Rise as indicated by 14C data for stations of R/V Professor Shtokman

Sedimentation of pelagic biogenic coccolithic-foraminiferal sediments predominates in the section of the South Atlantic ridge between 20° and 30°S. Sedimentation rate and thickness of Late Quaternary sediments differ in the rift valley, the crestal section of the ridge, its flanks and transform faults. Holocene and layers representing the most recent and pen¬ultimate continental glaciations and the last interglacial are distinguishable in the late Quaternary profile. During their development, changes in the mean annual sea surface temperature in the tropical zone of the South Atlantic were minimal, i.e. 1-2°C.

Pore-water concentration of chloride in sediment cores and equilibrium temperatures and gas bubble analysis at ROV stations from the Vodyanitskii mud volcano

Vodyanitskii mud volcano is located at a depth of about 2070 m in the Sorokin Trough, Black sea. It is a 500-m wide and 20-m high cone surrounded by a depression, which is typical of many mud volcanoes in the Black Sea. 75 kHz sidescan sonar show different generations of mud flows that include mud breccia, authigenic carbonates, and gas hydrates that were sampled by gravity coring. The fluids that flow through or erupt with the mud are enriched in chloride (up to 650 mmol L**-1 at 150-cm sediment depth) suggesting a deep source, which is similar to the fluids of the close-by Dvurechenskii mud volcano. Direct observation with the remotely operated vehicle Quest revealed gas bubbles emanating at two distinct sites at the crest of the mud volcano, which confirms earlier observations of bubble-induced hydroacoustic anomalies in echosounder records. The sediments at the main bubble emission site show a thermal anomaly with temperatures at 60 cm sediment depth that were 0.9 °C warmer than the bottom water. Chemical and isotopic analyses of the emanated gas revealed that it consisted primarily of methane (99.8%) and was of microbial origin (dD-CH4 = -170.8 per mil (SMOW), d13C-CH4 = -61.0 per mil (V-PDB), d13C-C2H6 = -44.0 per mil (V-PDB)). The gas flux was estimated using the video observations of the ROV. Assuming that the flux is constant with time, about 0.9 ± 0.5 x 10**6 mol of methane is released every year. This value is of the same order-of-magnitude as reported fluxes of dissolved methane released with pore water at other mud volcanoes. This suggests that bubble emanation is a significant pathway transporting methane from the sediments into the water column.

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.

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.

Annotated record of the detailed examination of Mn deposits from R/V Robert Conrad Cruise 06 stations

The cores described in this report were taken during the R/V Robert Conrad Cruise 06 from May until June 1963 by the Lamont Geological Observatory, Columbia University. A total of 5 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 179 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 179 undertaken by the Woods Hole Oceanographic Institution from April until May 1952. A total of 25 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 5 Expedition stations

The cores and dredges described in this report were taken during the VEMA 5 Expedition from November until December 1954 by the Lamont Geological Observatory, Columbia University from the R/V Vema. A total of 48 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 164 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 164 undertaken by the Woods Hole Oceanographic Institution from July until September 1950. A total of 63 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 Rehoboth Cruise 5 stations

The cores described in this list were taken on the RE05 Expedition in March 1950 by the Lamont-Doherty Earth Observatory from the R/V Rehoboth. A total of 13 cores were recovered and are available at LDEO for sampling and study.