Geology of the Conterminous United States at 1:2,500,000 Scale -- A Digital Representation of the 1974 P.B. King and H.M. Beikman Map

This CD-ROM contains a digital version of the Geologic Map of the
United States, originally published at a scale of 1:2,500,000 (King
and Beikman, 1974b). It excludes Alaska and Hawaii. In addition to
the graphical formats, the map key is included in ASCII text.
A geographic information system (GIS) allows combining and
overlaying of layers for analysis of spatial relations not readily
apparent in the standard paper publication. This disc contains only
geology. However, digital data on geology, geophysics, and
geochemistry can be combined to create useful derivative products--
for example, see Phillips and others (1993).
This CD-ROM contains a copy of the text and figures from
Professional Paper 901 by King and Beikman (1974a). This text
describes the historical background of the map, details of the
compilation process, and limitations to interpretation. The digital
version of the text can be searched for keywords or phrases.

本CD-ROM包含美国地质图的数字版本，该原版纸质图件最初以1:250万比例尺出版（King与Beikman，1974b），未涵盖阿拉斯加与夏威夷地区。除图形格式外，该数据集还附带ASCII文本格式的地图图例。
借助地理信息系统（Geographic Information System，GIS），可对各图层进行合并与叠加，以分析标准纸质出版物中难以直观呈现的空间关联关系。本CD-ROM仅包含地质类数据。不过，可将地质、地球物理与地球化学的数字数据进行整合，以生成具备实用价值的衍生产品——相关示例可参见Phillips等人（1993）的研究。
本CD-ROM还收录了King与Beikman（1974a）所著《专业报告901》中的文本与插图副本。该文本阐述了该地图的历史背景、编绘流程细节以及解译工作的局限性。用户可对该数字版本的文本进行关键词或短语检索。