Appendix A
Data Dictionary

The data dictionary contains definitions of the sediment's geological, physical, and chemical characteristics incorporated in the database. An example may be seen again here in table 4 from the data dictionary section. These definitions are also available in the Access version of the database in the status bar of the "datasheet view" or in the description field of the "design view".

The Pontchartrain database fields (see appendix D to download database) are a subset of those in the Master Data Dictionary (Buchholtz ten Brink and others, unpub. data, maintained at the USGS Coastal and Marine Geology Field Center, Woods Hole, MA 02543). The Pontchartrain data dictionary is downloadable here (Microsoft® Excel) with three sets of parameter descriptors: a short version, an intermediate-length version, and a full description. In the database, these parameters are divided into eight tables:

1. Station data
2. Inorganic chemical data (including metals)
3. General organic data (including "total" PCB and PAH)
4. Specific organic data A: PCBs and pesticides congeners
5. Specific organic data B: PAH congeners
6. Specific organic data C: Aliphatic hydrocarbons
7. Organic data D: Miscellaneous organic compounds
8. Sediment texture (grain size)

For these tables, the short parameter descriptors are used as field headings. For other questions related to data dictionary, see the above-mentioned section.