END-USER NEEDS AND IMPLEMENTATION CONSIDERATIONS FOR A WEB-ACCESSIBLE PETROGRAPHIC DATABASE

The Division of Natural Sciences at Lewis-Clark State College is compiling a georeferenced database of hand samples, and petrographic and geochemical data collected from Hells Canyon by Vallier. This database is now accessible (http://www.lcsc.edu/hellscanyon/), as a resource for researchers in the canyon. Because it is impossible to anticipate all the ways that researchers might use the data, or the ways in which they would like to search for it, any search interface for the data must provide access to all the features of the dataset. We anticipate that the most common styles of using the database will be to access the status of current knowledge or to investigate patterns in the already established data. In the first case, most searching will be by geographic coordinate, or data type (e.g. petrography, geochemistry, hand-sample availability, etc.), whereas in the second case, searching will be for geographic locations of samples with specific values within a data type, or for samples with a specified, multidimensional set of attributes (e.g. SiO2 > 70 wt% and age=Permian). The art of hosting searchable databases on the Web is still evolving. There are many small technical details that must be addressed to provide the greatest search flexibility without requiring specialized database knowledge on the part of the end user or the data-recording geologist. We have found that the most efficient way to address these issues is by using standard software (i.e. Microsoft Excel and Access) to compile the data, and hand-coding the query interface using ASP or PERL. Careful monitoring of usage statistics aids maintenance and upgrades of both the underlying database and the search interface so that they meet the needs of the end users.