GSV Geological Unit (50K) - Age

Geological units represented as two dimensional polygons, designed for portrayal at 1:50 000 scale. The polygon edges are constructed from the corresponding geological contacts and faults layer. Theme based on the 2008 version of the IUGS International stratigraphic chart (International Commission on Stratigraphy : http://www.stratigraphy.org/).以二维多边形表征的地质单元，专为1:50000比例尺的制图需求而设计。多边形边界由对应的地质接触面与断层图层构建生成。本数据集的主题基于2008版国际地质科学联合会（International Union of Geological Sciences, IUGS）国际地层表（国际地层委员会：http://www.stratigraphy.org/）。