Geologic Map of Alaska: geologic units

This dataset consists of a polygon coverage and associated
attribute data derived from the 1980 Geologic Map of Alaska
compiled by H.M. Beikman and published by the U.S. Geological
Survey. The map is a regional summary of geologic formations and
units that can be shown cartographically at 1:2,500,000. This
digital dataset includes all 184 map units from the original
map. 182 are geologic units; the others are polygons for large
glaciers and lakes. This coverage is not intended to be a
complete representation of the printed geologic map. It does NOT
include faults, locations of volcanoes or volcanic vents, the map
explanation, correlation charts or description of map units.

本数据集包含由H.M. 贝克曼（H.M. Beikman）编制、美国地质调查局（U.S. Geological Survey）发布的1980年版《阿拉斯加州地质图》衍生而来的多边形覆盖数据集及相关属性数据。该地图为地质建造与地质单元的区域汇总成果，可按1:250万比例尺进行制图表达。本数字数据集包含原版地图全部184个制图单元，其中182个为地质单元，剩余2个为对应大型冰川与湖泊的多边形区域。本覆盖数据集并非印刷版地质图的完整复刻，其未包含断层、火山或火山喷口位置、地图图例、地层对比图表以及地质单元说明文档。