Pontchartrain Basin: Bottom Sediments and Related Environmental
This appendix provides the full sediment data in eight linkable tables in three
formats (see appendix A for list of tables). The Microsoft® Access format presents the eight tables under a
single database (pont_db.mdb). In Microsoft® Excel (spreadsheet) format the eight
tables are available as tabbed sheets within "pont_db.xls". The tab-delimited version is presented as eight
text files in a single directory, sed_data/db_txt. A ninth table has been added in
each format for reference use only and lists the Chemical Abstracts
Service (CAS) Registry numbers. Users with the appropriate software may
click on the linked file names below and open the data directly into the application.
The spreadsheet version is convenient for data analysis and graphical display. The
database version is suited for complex data manipulation and querying, transfer to other formats, and
creation of special interpretive tables. The tab-delimited version permits transfer of the
data to any desired software.
Quality Control and Methodology Differences
The data tables contain information from
many sources and alternative methodologies that are not always directly comparable.
Also, unresolvable problems or uncertainties were found within some data
sets. Results of quality screening
are abbreviated in the "Q" fields (qualifier fields) next to each
concentration field, and important notes about methods and sample types
are given in other fields. A " W" preceding other notes in the quality-control field signifies
unresolved problems suggesting that the data be checked before use. "0" in a
concentration field means that the constituent was below detection limit for the method
utilized. Commonly occurring annotations are shown as abbreviations or
others may be described in text. Users are responsible
for selection of data for their specific purposes. Definitions of screening
codes and additional data quality notes are provided in appendix
B or can be downloaded as a Microsoft® Word document below.
Note that all data are given as presented in raw form by original sources.
As discussed in the database structure section,
this database is not normalized. Qualifier and descriptive fields are in the
same tables with analytical data fields, rather than placing them in separate tables. This
is partly designed to avoid the separation of critical background information and quality
designations from analytical data. Redundancy is permitted where this offers a template to
permit data entry in original format. For example, both state plane coordinate and
latitude/longitude fields are provided. Preserving data in original form and units is a
critical element of this database and minimizes the need for secondary users to refer to
obscure original sources.
1. The Access databases were created in version 8.0 (Access 97) and must be
imported if used with lower versions.
2. The Excel files can be opened with version 5.0 or higher.
3. Windows users
may download the WinZip utility from http://www.winzip.com/download.htm, and Macintosh users may download StuffIt Expander from
for use in restoring the compressed .zip files.