LUQUILLO 
complete sidescan sonar mosaic, bathymetric data, Holocene-age sediment isopach map, Pleistocene structural map, ship tracklines, Puerto Rico coastline, and sediment sample locations and analysis information. All of the data are mapped in Universal Transverse Mercator
projection (UTM), zone 20, with the Clarke 1866 reference ellipsoid. 

SIDECAN SONAR
To register the sidescan mosaic for use within Arc/INFO, I first gridded (using Arc/INFO gridimage) the raster image generated by PCI. Then used
gridwarp in Arc to register the image. The file whole.lnk is the file representing the corner points and the corresponding UTM coordinates of the
original raster image. This link file is used by gridwarp to perform the georeferencing transformation of the raster image. The final gridded and
registered product is in the directory maps/sidescan.

BATHYMETRY
The bathymetric data were generated by digitizing existing contour maps (Schwab and others, 1996b). Two directories are associated with this data -
one is a line coverage and the other a polygon coverage. Because of the density of the contours, a polygon coverage with a color coded depth
relationship is generally easier to work with. Included with these data are a file called bathy.shd which is the Arc/INFO shadeset used for the image
displayed here (polygon coverage). The line coverage has an attribute called linetype. By using the included symbolset contours.lin with this attribute,
the contours will be displayed with the appropriate dashes and hachures. The screen display is white lines, but prints as black. 

PLEISTOCENE STRUCTURE CONTOURS
As with the bathymetric data, this data was generated by digitizing existing contour maps(Schwab and others, 1996b). There are also 2 coverages, the
line coverage and the polygon coverage. By using the included shadeset bathy.shd, the same color range as the bathymetric data is displayed. The line
coverage also has an attribute called linetype and can be treated the same way as the bathymetric data.

HOLOCENE-AGE SEDIMENT THICKNESS
This isopach data was generated by digitizing existing contour maps (Schwab and others, 1996b) and has a line coverage and attribute linetype so that
it can be treated in the same manner as the bathymetric and Pleistocene datasets. However, for the polygon coverage, the Arc/INFO shadeset file
isopach.shd (included on the CD-ROM) is more appropriate.

SEDIMENT SAMPLES
Sediment samples contained in this dataset are only those collected offshore. Samples have a number preceded by either "Bor" or "GS". The numbers
proceded by "Bor" indicate samples collected in 1992 aboard the RV Boriken; numbers proceded by "GS" indicate samples collected in 1991 aboard
the RV Jean A; and numbers followed by "A" or "B" indicate duplicate analyses. The sed-code attribute simply assigns a number to each of the
classifications given. These values are as follows:

Sed-code 1 ----- clayey_silt
Sed-code 2 ----- sand_silt_clay
Sed-code 3 ----- sandy_silt
Sed-code 4 ----- silty_sand
Sed-code 5 ----- sand
Sed-code 6 ----- gravel>10%
Sed-code 7 ----- silt

TRACKLINES
The tracklines were derived from the sidescan sonar navigation at 1 minute intervals.

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MAYAGUEZ
complete sidescan sonar mosaic, bathymetric data, ship tracklines, Puerto Rico coastline, and sediment sample
locations and analysis information.  All of the data are mapped in a Universal Transverse Mercator projection (UTM), zone 19, using the WGS84
reference ellipsoid.

BATHY
The digitized bathymetry was furnished courtesy of the Puerto Rico Water Resources Division.  In this Arc/Info line coverage, the bathy-id
attribute corresponds to the bathymetric value in meters.

INTERP
This Arc/INFO polygon coverage represents the general geologic interpretation of the sidescan-sonar imagery.

SAMPLES
The sediment samples were collected using a Shipek grab sampler.  The sediment textural analysis results are included in this Arc/INFO point
coverage.

SIDESCAN
This directory contains 2 'TIFF' images and their associated world file for use in Arc/Info.  The file 'rawsonar.tif' is the sidescan-sonar mosaic
with no image enhancement applied.  This file is the image file used to generate rawgrd.  The other 'TIF' image, 'anasco.tif', is the enhanced image
from which sonargrd is derived.   These 'TFW' files associated with each of these images allows Arc/INFO to geographically register the images. 
The resolution of these images is 1m/pixel.