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Open-File Report 2005-1001
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 OFR 2005-1001 Home   /    Procedures    /    East-Coast Database   /    GIS Data Catalog

U.S. Geological Survey Open-File Report 2005-1001
USGS East-Coast Sediment Analysis: Procedures, Database, and GIS Data

EAST-COAST DATABASE


Database Dictionary

An integral part of any functioning database is the dictionary that explains the structure and content of the database. It contains an index and definitions of the parameters measured and lists the fields which record and qualify those parameters. Extracting data from the database is facilitated by reference to this document because it provides a means to keep track of abbreviations and the sediment fields names. Below is the database dictionary for the USGS East Coast Sediment Texture Database. Field names are listed in the order they are found in the database.

Short Field Name Full-Length Field Name Field Description

GROUP

Group

Number assigned to data based on source

1 = Samples taken before start of the joint USGS/WHOI project
2 = USGS/WHOI Atlantic Continental Margin Program stations
3 = Sediment entirely or partially analyzed, processed, or visually described by USGS Woods Hole scientists; most samples analyzed in the USGS Woods Hole Sediment Laboratory.

DB_ID

USGS unique sample identifier

Unique identification number generated in the sedimentation laboratory of the USGS's Woods Hole Coastal and Marine Science Center. For samples analyzed after 1980 this identifier consists of 2 characters and 3 numerics (e.g. AS114).  For samples analyzed before1980, this identifier consists of 4 numerics possibly followed by as many as 2 characters.

FIELD_NO

Field Identifier

Sample name or number as assigned in the field by the Chief Scientist.

PROJECT

Project name

Project name or number under which samples were taken or data generated; sometimes project name indicates a more specific area.

CRUISE_ID

Cruise ID

Name or number of cruise on which sample collected. Historically cruise identifiers were a combination of ship name, year of cruise and cruise leg. In more recent years, cruise identifier is a sequential serial number assigned to field activities within a specific year.

CONTACT

Principal contact

Name of Principal Investigator or Chief Scientist responsible for data collection (usually first initial and last name)

AREA

Area

General geographic area of data collection. Name is general enough to easily locate area on a state map.

LATITUDE

Latitude

Latitude coordinate, in decimal-degrees, of sample location. South latitude recorded as negative values.

LONGITUDE

Longitude

Longitude coordinate, in decimal degrees, of sample location. West longitude is recorded as negative values.

DEPTH_M

Depth or sounding in meters

Measured depth, in meters, of water overlying sediment at sample time. Depth value is not corrected for tides.

T_DEPTH

Top depth

Top depth of sample, in centimeters, below the sediment-water interface.

B_DEPTH

Bottom depth

Bottom depth of sample, in centimeters, below the sediment-water interface.

DEVICE

Sampling device

Device used to collect the sample.

MONTH_COLL

Month collected

Calendar month sample collected.

DAY_COLL

Day collected

Calendar day sample collected.

YEAR_COLL

Year collected

Calendar year sample collected.

MONTH_ANAL

Month analyzed

Calendar month sample collected.

DAY_ANAL

Day analyzed

Calendar day sample collected.

YEAR_ANAL

Year analyzed

Calendar year sample collected.

WEIGHT

Weight

Weight of dry sample in grams.

GRAVEL_PCT

%Gravel

Gravel content in percent dry weight of the sample (particles with nominal diameters greater than 2 mm; -1 phi and larger.

SAND_PCT

%Sand

Sand content in percent dry weight of sample (particles with nominal diameters less than 2 mm but greater than or equal to 0.0625 mm; 0 phi through 4 phi).

SILT_PCT

%Silt

Silt content in percent dry weight of the sample (particles with nominal diameters less than 0.0625 mm but greater than or equal to 0.004 mm; 5 phi through 8 phi, inclusive).

CLAY_PCT

%Clay

Clay content in percent dry weight of the sample (particles with nominal diameters less than 0.004 mm; less than 8 phi).

CLASSIFICATION

Classification

Sediment description based on rigorous definition (usually Shepard,1954).

Classes include:

GRAVEL – gravel equal to or greater than 50 percent

GRAVELLY SEDIMENT – gravel equal to or greater than 10 percent, but less than 50 percent.

SAND – sand equal to or greater than 75 percent

SILTY SAND - sand less than 75 percent and equal to or greater than 50 percent, silt greater than clay, and clay less than 20 percent

CLAYEY SAND - sand less than 75 percent and equal to or greater than 50 percent, clay greater than silt, and silt less than 20 percent

SILT - silt equal to or greater than 75 percent

SANDY SILT – silt less than 75 percent and equal to or greater than 50 percent, sand greater than clay, and clay less than 20 percent

CLAYEY SILT - silt less than 75 percent and equal to or greater than 50 percent, clay greater than sand, and sand less than 20 percent

CLAY – clay equal to or greater than 75 percent

SANDY CLAY - clay less than 75 percent and equal to or greater than 50 percent, sand greater than silt, and silt less than 20 percent

SILTY CLAY - clay less than 75 percent and equal to or greater than 50 percent, silt greater than sand, and sand less than 20 percent

SAND SILT CLAY – clay, sand, and silt greater than 20 percent each

MEDIAN

Median

Middle point in the grain size distribution in phi units.

MEAN

Mean

Average value in the grain size distribution in phi units.

STDEV

Standard deviation (sorting)

Standard deviation (root mean square of the deviations) of the grain size distribution in phi units.

SKEWNESS

Skewness

Skewness (deviation from symmetrical form) of the grain size distribution in phi units.

KURTOSIS

Kurtosis

Kurtosis (degree of curvature near the mode) of the grain size distribution in phi units.

MODE1CLASS

Mode 1 class

First mode (particle size that occurs the most number of times) in phi units.

MODE1FREQ

Mode 1 strength

Modal strength of the first mode in percent.

MODE2CLASS

Mode 2 class

Second mode in phi units.

MODE2FREQ

Mode 2 strength

Modal strength of the second mode in percent.

MODE3CLASS

Mode 3 class

Third mode in phi units.

MODE3FREQ

Mode 3 strength

Modal strength of the third mode in percent.

NMODES

No. of modes

Number of modes.

PHIm5

-5 Phi

Weight percent of the sample in the -5 phi fraction and coarser (nominal diameter of particles greater than or equal to 32mm); very coarse pebbles to cobbles

PHIm4

-4 Phi

Weight percent of the sample in the -4 phi fraction (nominal diameter of particles greater than or equal to 16mm, but less than 32mm); coarse pebbles.

PHIm3

-3 Phi

Weight percent of the sample in the -3 phi fraction (nominal diameter of particles greater than or equal to 8mm, but less than 16mm); medium pebbles.

PHIm2

-2 Phi

Weight percent of the sample in the -2 phi fraction (nominal diameter of particles greater than or equal to 4mm, but less than 8mm); fine pebbles.

PHIm1

-1 Phi

Weight percent of the sample in the -1 phi fraction (nominal diameter of particles greater than or equal to2mm, but less than 4mm); very fine pebbles (granules).

PHI_0

0 Phi

Weight percent of the sample in the 0 phi fraction (nominal diameter of particles greater than or equal to 1mm, but less than 2mm); very coarse sand.

PHI_1

1 Phi

Weight percent of the sample in the 1 phi fraction (nominal diameter of particles greater than or equal to 0.5mm, but less than 1mm); coarse sand.

PHI_2

2 Phi

Weight percent of the sample in the 2 phi fraction (nominal diameter of particles greater than or equal to 0.25mm, but less than 0.5mm); medium sand.

PHI_3

3 Phi

Weight percent of the sample in the 3 phi fraction (nominal diameter of particles greater than or equal to 0.125mm, but less than 0.25mm); fine sand.

PHI_4

4 Phi

Weight percent of the sample in the 4 phi fraction (nominal diameter of particles greater than or equal to 0.0625mm, but less than 0.125mm); very fine sand.

PHI_5

5 Phi

Weight percent of the sample in the 5 phi fraction (nominal diameter of particles greater than or equal to 0.031mm, but less than 0.0625mm); coarse silt.

PHI_6

6 Phi

Weight percent of the sample in the 6 phi fraction (nominal diameter of particles greater than or equal to 0.016mm, but less than 0.031mm); medium silt.

PHI_7

7 Phi

Weight percent of the sample in the7 phi fraction (nominal diameter of particles greater than or equal to 0.008mm, but less than 0.016mm); fine silt.

PHI_8

8 Phi

Weight percent of the sample in the 8 phi fraction (nominal diameter of particles greater than or equal to 0.004mm, but less than 0.008mm); very fine silt.

PHI_9

9 Phi

Weight percent of the sample in the 9 phi fraction (nominal diameter of particles greater than or equal to 0.002mm, but less than 0.004mm); coarse clay.

PHI_10

10 Phi

Weight percent of the sample in the 10 phi fraction (nominal diameter of particles greater than or equal to 0.001mm, but less than 0.002mm); medium clay.

PHI_11

11 Phi

Weight percent of the sample in the 11 phi fraction and finer (nominal diameter of particles greater than or equal to 0.5(m); fine clay.

ANALYST

Analyst

Name (usually first initial and last name) of person who performed the grain size or physical properties analysis.

ANAL_COMM

Comments on analyses

Any further information about sediment analysis for all or specific parameters in this table.

LITHOLOGY

Lithology

General lithologic description of sample.

COMMENTS

Comments

Comments on sample collection or lithology.

 

  Database Acknowledgments Go to Next Section
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