Annotated record of the detailed examination of Mn deposits from R.R.S. "Discovery" Cruise 2 stations

This report gives a comprehensive general description of the scientific activities of Cruise 2 of R. R. S. 'Discovery'. These were largely geological and geophysical and were part of the British contribution to the International Indian Ocean Expedition. In addition to the thirteen geophysicists and geologists on board, there were five scientists involved in ocean chemistry, temperature measurements and ornithology making continuous observations - their accounts are also included. The report of a geological expediton ashore in the Seychelles is given in section 6.

Annotated record and chemical analyses of a polygenetic manganese nodule (slab) from the Scott Plateau, Indian Ocean (core VA-16-13KD)

A large manganese nodule (manganese slab) was dredged from 2100 m on the Scott Plateau by R.V. Valdivia in 1977. It is an irregular ellipsoid, with a maximum dimension of 28 cm, parallel to the sea floor. Chemical analyses show that Mn and Fe proportions are comparable, and total Ni + Cu + Co content averages 0.7%. The nodule has a complex growth history which started with radial upward growth leading to coalescing into a continuous crust. The crust was coated with horizontal layers. After fracturing and infilling of cracks with calcareous sediment, further layers encased the nodule.

Annotated record of the detailed examination of Mn deposits from the H.M.S. Penguin expedition to the Coral Sea

The analyses of the samples from the Balfour Shoal show that these deposits contain a very large quantity of carbonate of lime, ranging from 88.7 per cent, on the summit to 71.9 per cent, in the deeper water at the base of the cone. The decrease in the quantity of carbonate of lime with increase of depth is not quite regular; still, a general fall in the percentage of lime is clearly indicated from shallower to deeper water. As might be expected in such a circumscribed area, there is a great uniformity both in the chemical composition and relative abundance of the organic and inorganic constituents of the deposits. In all cases the carbonate of lime is almost wholly made up of the dead shells which have fallen from the surface waters - belonging to Plankton organisms such as Pteropods, Heteropods, pelagic Foraminifera and coccoliths. The calcareous shells were in very many cases discoloured brown or black by depositions of the peroxide of manganese. On the north-east steep side of the Balfour Shoal there were indications that depositions of manganese peroxide were more abundant than elsewhere. In 1645 fathoms, there was an angular fragment of a mottled yellowish jasper coated with manganese peroxide, and in 1570 fathoms there were three characteristic spherical black manganese nodules from one-half to three-fourths of an inch in diameter, quite similar to those procured by the Challenger in many areas of the Pacific and Atlantic. In one of these nodules the nucleus was a sub-angular fragment of a light-coloured augite-granophyre.

Annotated record of the detailed examination of Mn deposits from DSDP Site 162, Leg 16 (Cores 16-162-1, 16-162-2, 16-162-8, 16-162-9 and 16-162-15)

DSDP 162 is located due north of DSDP 161 on the lower west flank of the East Pacific Rise about 3900 km west of the crest. It is in the Clarion-Clipperton block, about 80 km south of the Clarion Fracture Zone. The site lies at the extreme northern edge of the zone of thick sediments that parallels the equator in the Pacific and marks the region of high biological productivity.

Annotated record of the detailed examination of Mn deposits from T3 Ice Island in the Arctic Ocean

The cores described were taken by the personnel of the Lamont-Doherty Earth Observatory (LDEO) on the T3 Antarctic Ice Island in the Arctic Ocean from 1953 until 1969. The recovered cores are available at Lamont-Doherty Earth Observatory for sampling and study.

Annotated record of the detailed examination of Mn deposits from Drift Station Alpha in the Arctic Ocean

The cores described were taken by the personnel of the Lamont-Doherty Earth Observatory (LDEO) on the Drift Station Alpha in the Arctic Ocean from August 1957 until June 1958. A total of 16 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 C.S.S. Hudson Cruise 19 (1967) stations

The Bedford Institute of Oceanography provided ship time on the C.S.S. Hudson during the B.I.0. 1967 Metrology and IODAL Cruise for surveying two separate bottom features in the North Atlantic; the Flemish Cap and the San Pablo Seamount one of the Kelvin Seamounts (also known as the New England Seamounts) about 400 miles SSE of Halifax, Nova Scotia. Underwater photography, dredging, and drilling showed San Pablo seamount to have a very considerable covering of manganese deposit, which may be recoverable by mining. San Pablo Seamount was surveyed and sampled; good hauls were made both on the top and on the slopes, at various depths from 500-1000 fathoms; in all cases samples of an unusual stratified manganese-iron ore were recovered. In the hope of gaining additional information in the immediate sample area, one of the dredges had been previously modified to accommodate underwater photographic equipment. X-ray chemical analyses indicate that the ore contains 20 to 25 per cent MnO2, with similar amounts of Fe2O3. Since bottom photographs indicate that these deposits form a continuous cover 1 foot to 3 feet thick over most of the seamount, it is estimated that there are ore reserves in the order of 10 to 30 M tons above 1,000 fathoms.

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

The cores and dredges described in this report were taken on the ARIES Expedition from November 1970 until October 1971 by the Scripps Institution of Oceanography from the R/V Thomas Washington. A total of 65 cores and dredges were recovered and are available at Scripps for sampling and study.

Annotated record of the detailed examination of Mn deposits from DSDP Hole 2-8

The Atlantic Advisory Panel proposed that Site 8 should be drilled on the rise between the Hatteras and Sohm Abyssal Plains (lat 35° 2l'N., long 67° 3l'W.) This location was considered to offer the best opportunity for realizing two primary objectives. The first of these objectives was to sample and date the oldest available rock in a region adjacent to the North American continent and as far as possible from the Mid-Atlantic Ridge. The second objective relates to the potential paleobiological and paleoecological information that could be derived from the sedimentary column in this general area.

Annotated record of the detailed examination of Mn deposits from DSDP Hole 2-12C

Site 12 of this report formerly was designated 14 by the Atlantic Advisory Panel. It was drilled in the Cape Verde Basin (latitude 19° 42'N, longitude 26° 01'W), which is underlain by 2000 to 2100 feet (0.9 to 1.1 seconds reflection time) of sediment. The bottom topography of the basin is fairly smooth but not to the degree of an abyssal plain. Site 12 was selected to provide material for paleontological investigations.

Annotated record of the detailed examination of Mn deposits from DSDP Site 159, Leg 16 (Cores 16-159-6 and 16-159-12)

DSDP 159 is one of a series of sites in the eastern equatorial Pacific on the west flank of the East Pacific Rise. It was selected by the Pacific Site Selection Panel on the premise that if hydrothermal processes on the crest of the East Pacific Rise supply the transition metals, a broad zone of such deposits should be present immediately above basement over the entire flank of the Rise.

Annotated record of the detailed examination of Mn deposits from PR II, CORPUS 4 Cruise, R/V Atlantic Twin off the coast of Puerto Rico

The dredges described in this report were taken on the PR II, CORPUS 4 Expedition in January 1969 by the USGS Woods Hole Coastal and Marine Science Center from the R/V Atlantic Twin. Dredges recovered and are available at USGS Woods Hole Coastal and Marine Science Center for sampling and study.

Annotated record of the detailed examination of Mn deposits from DSDP Site 20, Leg 3 (Holes 3-20, 3-20A and 3-20C)

Prior to arrival on this site, the only survey data available was from the Vema-20 crossing of the area. The recommended site location was over a relatively smooth valley in the bottom topography at about 4750 meters (15,580 feet) depth (uncorrected), about 10 kilometers wide E-W between peaks (or ridges) on either side. Sediment thickness was unknown. The center of the valley is near the peak of a wide (40 to 50 kilometers) positive magnetic anomaly, identified as Magnetic Anomaly 30 in the hypothesized geomagnetic time scale with an age of 72 million years.

Annotated record of the detailed examination of Mn deposits from DSDP Hole 2-9A

The Atlantic Advisory Panel proposed that Site 9 should be drilled on the northeastern flank of the Bermuda Rise (lat. 32° 37' N., long. 59° 10' W.), which is about 100 miles west of the Sohm Abyssal Plain. The bottom of this region consists of low linear ridges that are roughly parallel and oriented in a northwest-southeasterly direction. Scattered seamounts, some of which have peaks 2000 fathoms (3660 meters) below sea level, arise from the otherwise featureless sea floor between the ridges. The primary purpose in drilling Site 9 was to examine a sedimentary column where seismic reflectors were largely absent and to determine the age of sediments overlying acoustical basement in the examination of sea floor spreading.

Annotated record of the detailed examination of Mn deposits from R/V Tokaidaigaku Maru II Cruise GDP-1 stations

The present paper, deals with the results of the bottom sampling. Sampling devices were a gravity corer for heat flow measurement and dredges of bucket type.