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.