Digital Slides Project
A Digital Library of Geologic Field Relations and Features

(Browse the Digital Library)

Jeffrey Lee
Department of Geological Sciences
Central Washington University, Ellensburg, WA

South vergent S1 fold, Kangmar Dome, Tibet; view to the west.


This collaborative project, funded by a grant from the Digital Materials Development Program of the Northwest Academic Computer Consortium, has scanned slides showing a wide range of geologic field relations and features from diverse, world-wide settings into a digital format for use in the classroom, laboratory, and for web page development of course materials.

Geology is a field-based science, and geologic field relations form the foundation for understanding geologic processes. Therefore, a critical component of an undergraduate education in geology is mastering the skills required to identify a wide variety of geologic field relations and features. For a number of reasons, it is not practical to conduct all of our geology courses in the field. In the past, we illustrated critical field relations and features with slides gathered from our research projects and travels. These slides are dispersed among a number of faculty and are generally poorly organized. Creating a digital library of our slide collections enhances the student learning environment, facilitates the development of web-based exercises, and improves our ability to use a wide range of slides in all of our classes.

The Digital Library

Slides were scanned at 300 dpi and 400% with a Nikon Supercool Scan 2000 scanner with an autofeed mechanism attached to an Apple computer. Scanned slides were saved as tiff files and then batch converted (RGB mode; quality 5; scans 3; matte none) to jpeg format using Adobe Photoshop. Scanned slide files are housed on a Dell Dimension 4100 (866 MHz Pentium III, 256 MB memory, 60 GB disk) running Linux (Red Hat 7.0 distribution). The slides and annotations are organized in a relational database (MySQL 3.23) and slides are accessed for administration and display purposes by scripts (Perl 5.6.0) linked to the digitalslides web server (Apache 1.3.14). Scanned slides were then cataloged, via a web interface, by contributors. Information provided for each slide includes location, geologic feature, geographic orientation, scale, year of photograph, photographer, index terms, other information. Over half the slides are cataloged; cataloging continues. A Digital Library search engine allows one to find specific geologic features.

Currently, the searchable Digital Library contains more than 2000 slides. Primary topics include general earthquakes, geomorphology, geologic hazards, physical volcanology, structural geology, and tectonic geomorphology of active faults. For more information about the Digital Library, contact Jeff Lee.


Professors Wendy Bohrson, Jim Hinthorne, Lisa Ely, Jeff Lee, Steve Lundblad, Meghan Miller, Charlie Rubin, and Nick Zentner, Department of Geological Sciences, Central Washington University, and Professor Anita Grunder, Department of Geological Sciences, Oregon State University, contributed slides. Also included are a set of geologic hazards slides from the National Geophysical Data Center, NOAA.

Mike August, an undergraduate geology major, Central Washington University, scanned the slides and Craig Scrivner, System Administrator for the Department of Geological Sciences, Central Washington University, created the slide editor interface and slide search script.

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