USGS CMG I-7-90-AT Metadata

To study the movement of sediment particles in the water column, the
accumulation of sediment particles on the seabed, and the effects that sediment
particles have on geochemical processes in the water column and seabed.

Stratigraphic analysis, sedimentary structures, radiochemistry, bulk
density, mineralogy and texture, infaunal assemblages present on the Amazon
shelf, bottom profiles, high-resolution reflection seismic profiles, control of
redox reactions by iron oxides in the seabed.

Measurements and samples were collected at 42 different stations on the
continental shelf. Of these 42 stations, 35 were examined in detail by multiple
coring. As many as 8 cores were taken at sites where smaples were required for
geochemistry, biology and stratigraphy. Cores taken primarily for stratigraphic
analysis were box cores (23), kasten cores (53), and one piston core (1). In
addition, 11 stations were sampled with Shipek grab sampler. Cores were
radiographed to document sedimentary structures and the majority were subsampled
for laboratory analysis involving radiochemistry, bulk density, mineralogy and
texture. Box core or grab samples were analyzed from a majority of stations by
scientists from UFRJ as a survey of infaunal assemblages present on the Amazon
shelf. In addition to sea bottom campling, 3.5 kHz profiles were obtained along
the transit lines connecting each station and approximately 100 km of GEOPULSE
high-resolution reflection seismic profiles were collected. During this leg two
coastal sampling trips were made to the Cabo Cassipore and Ponta do Costa areas
with small boats by scientists from UFPA, UFF and the USA.

The control of redox reactions by iron oxides in the seabed was examined at 6
stations by sampling sediment-water solute fluxes and interstitial water
chemistry and by monitoring reaction rate experiments, authigenic mineral
formation, and benthic community activity (stations 3204, 3205, 3211, 3216,
3221, and 3226). Two stations (3201 and 3209) were sampled in the southern
portion of the study area for measurement of sediment-water fluxes and
benthic-community characteristics. Grab samples were taken in sands at the
seaward-most station, 3229. Water column samples and CTD profiles were obtained
at all the seabed geochemistry/benthic biology stations (3201, 3204, 3205, 3209,
3211, 3216, 3221, and 3226). Surface plankton tows and bottom water samples were
taken at stations 3201, 3204, 3211, 3209, 3216, and 3221.

Rine, James M. and Nittrouer, Charles A. 1990. Report on field measurements and
sampling during AmasSeds Cruise III - CI9004. Marine Sciences Research Center,
State University of New York, NY. November 1990. 135 p.