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Geology and Resource Assessment of Costa Rica at 1:500,000 Scale --
A Digital Representation of Maps of the U.S. Geological Survey's 1987 Folio I-1865

By Paul G. Schruben

1996

Geologic map of Costa Rica

Project Overview

Conversion of the information from the original folio to a computerized digital format was undertaken to facilitate the presentation and analysis of earth-science data. Digital maps can be displayed at any scale or projection, whereas a paper map has a fixed scale and projection. However, most of the maps on this disc are not intended to be used at any scale more detailed than 1:500,000.

A geographic information system (GIS) allows combining and overlaying of layers for analysis of spatial relations not readily apparent in the standard paper publication. Digital information on geology, geophysics, and geochemistry can be combined to create useful derivative products.

History of the Maps

In 1986 and 1987, the U.S. Geological Survey (USGS), the Dirección General de Geología, Minas e Hidrocarburos, and the Universidad de Costa Rica conducted a mineral-resource assessment of the Republic of Costa Rica. The results were published as a large 80- by 50-cm color folio (U.S. Geological Survey and others, 1987). The 75-page document consists of maps as well as descriptive and interpretive text in English and Spanish covering physiographic, geologic, geochemical, geophysical, and mineral site themes as well as a mineral-resource assessment. The following maps are present in the original folio:
  1. Physiographic base map at a scale of 1:500,000 with hypsography, place names, and drainage.
  2. Geologic map at a scale of 1:500,000.
  3. Regional geophysical maps, including gravity, aeromagnetic, and seismicity maps at various scales.
  4. Mineral sites map at a scale of 1:500,000 showing mines, prospects, and occurrences.
  5. Volcanological framework of the Tilarán region important for epithermal gold deposits at a scale of 1:100,000.
  6. Rock sample locations, mining areas, and vein locations for several parts of the country.
  7. Permissive areas delineated for selected mineral deposit types.
  8. Digital elevation model.

This CD-ROM contains most of the above maps; it lacks items 1 and 8 and the seismicity and aeromagnetic maps of item 3. The linework was digitized from preliminary and printed maps with GSMAP (Selner and Taylor, 1987), a USGS-authored program for map editing and publishing. Conversion from GSMAP to ARC/INFO was accomplished through the use of the GSMARC program (Green and Selner, 1988). The arcs and polygons were tagged using Alacarte (Wentworth and Fitzgibbon, 1991).

Online Files for Costa Rica Assessment CD

View Costa Rica geology larger image

Description of DDS19 CD-ROM

Download entire CD - 27 mb .tar.Z compressed file.
Remember to uncompress, then untar.

Download ArcView1 for PC files only - 3.4 mb .tar file

Errata and bug reports for DDS19

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