CROSS SHELF 
WALOR AMS. 
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MEAN CURRENT 
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FicurE 1B8.—Site-specific sampling station array around 
regional station 5 (block 312). Stations 5-7, 5-13, 5-15, 5- 
17, 5-19, 5-21, 5-23, 5-24, 5-26, and 5-27 are secondary sta- 
tions (of lower priority) and have not been analyzed routinely. 
S=0.03+1.805 (Cl) 
(Sverdrup and others, 1942). Chloride was mea- 
sured in samples of the separated fine fraction by 
using the method of Aruscavage and Campbell 
(1982). This technique utilizes a specific ion elec- 
trode that measures most of the bromide as 
chloride and thus estimates the total chlorinity of 
the sample. The ratio of measured chloride to the 
total precipitated sea salts used to make salt cor- 
rections was 0.5535. The algorithm for making cor- 
rections for each metal concentration is 
C=U/(1-(Cl/0.5535)) 
where C is the corrected metal concentration, U is 
the uncorrected concentration, and Cl is the meas- 
ured chloride concentration in percent multiplied 
by 10-2. 
The field numbers (for example, M09-13-00-G 
and M10-05-28-BL) that identify samples in each 
data table have the following code. The first three 
characters indicate the cruise number; M09 stands 
for monitoring cruise 9. The station number appears 
after the first dash. In the examples given, 13-00 
is a station in the regional sample array; station 
05-28 is one of the site-specific stations around 
regional station 5 (see fig. 1B). A single alpha 
4 
character at the end of the field number identifies 
one of three replicates taken at each station for 
trace-metal analysis. Alternatively, the notation BL 
at the end of the field number indicates a blended 
composite sample made up of equal weights from 
each of the three replicates. Field numbers ending 
in X indicate that analyses were performed on the 
fraction of sediment finer than 60 pm. 
GRAIN-SIZE ANALYSIS TECHNIQUES 
Textural analyses were performed on wet sedi- 
ments to avoid the formation of clay aggregates. 
Homogenized samples were wet sieved by using a 
dispersant (5-percent Calgon) through a 63-ym sieve 
to remove silt and clay. The coarse fraction (contain- 
ing shells, if present) was dried, weighed, and then 
sieved through a 2-mm screen to remove the gravel, 
which was not further sized. The sand fraction was 
analyzed with a Rapid Sediment Analyzer (Schlee, 
1966). A gravimetric determination of the silts and 
clays was made by filtering. The size distribution of 
the silts and clays was determined with a Coulter 
Counter. Statistical parameters (mean, median, 
standard deviation, and so forth) were determined 
by the method of moments (Krumbein and Petti- 
john, 1938). All textural data are expressed in phi 
(¢) units, which are defined as -Log,D where D is 
the grain diameter in millimeters. 
Samples from sediment traps, sediment cores, and 
depth profiles from grab samples were often too 
small for a complete textural analysis. In such cases, 
the samples were passed through a 60-ym nylon 
sieve, and the percentage of dry sediment coarser 
and finer than 60 »m was determined gravimetrically. 
TRACE-METAL ANALYSIS PROCEDURES 
The analyses of trace metals in marine sediments 
were carried out by the U.S. Geological Survey 
Branch of Analytical Laboratories, Reston, Va. Con- 
centrations of the following elements were deter- 
mined: aluminum (Al), barium (Ba), cadmium (Cd), 
chromium (Cr), copper (Cu), iron (Fe), lead (Pb), 
manganese (Mn), mercury (Hg), nickel (Ni), vanadium 
(V), and zinc (Zn). The various procedures employed 
in each of the analyses are detailed below and sum- 
marized in table 1. 
PREPARATION OF STOCK SOLUTION A 
Exactly 0.5 g of ground bulk sediment or 0.2 g of 
the fine fraction was added to a covered teflon beaker 
