The State Geologic Map Compilation (SGMC) Geodatabase of the Conterminous United States

The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States (https://doi.org/10.5066/F7WH2N65) represents a seamless, spatial database of 48 State geologic maps that range from 1:50,000 to 1:1,000,000 scale. A national digital geologic map database is essential in interpreting other datasets that support numerous types of national-scale studies and assessments, such as those that provide geochemistry, remote sensing, or geophysical data. The SGMC is a compilation of the individual U.S. Geological Survey releases of the Preliminary Integrated Geologic Map Databases for the United States. The SGMC geodatabase also contains updated data for six States and seven entirely new State geologic maps that have been added since the preliminary databases were published. Numerous errors have been corrected and enhancements added to the preliminary datasets using thorough quality assurance/quality control procedures. The SGMC is not a truly integrated geologic map database because geologic units have not been reconciled across State boundaries. However, the geologic data contained in each State geologic map have been standardized to allow spatial analyses of lithology, age, and stratigraphy at a national scale. A full discussion of the procedures and methodology used to create this dataset is available in the accompanying report: Horton, J.D., San Juan, C.A., and Stoeser, D.B, 2017, The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States: U.S. Geological Survey Data Series 1052, 46 p., https://doi.org/10.3133/ds1052.美国本土州地质图汇编（State Geologic Map Compilation，SGMC）地理数据库（https://doi.org/10.5066/F7WH2N65）是一套无缝隙空间数据库，涵盖48份比例尺跨度为1:50000至1:1000000的州级地质图。国家级数字地质图数据库是解译各类支撑国家级尺度研究与评估的数据集的核心基础，相关研究与评估涵盖地球化学、遥感或地球物理等多个领域。SGMC由美国地质调查局发布的多份美国本土初步综合地质图数据库汇编而成。自初步数据库发布以来，SGMC地理数据库还新增了6个州的更新后数据，以及7份全新的州级地质图。通过严格的质量保证与质量控制（quality assurance/quality control，QA/QC）流程，初步数据集已完成大量错误修正与功能增强。SGMC并非真正意义上的一体化地质图数据库，因为地质单元在州界之间并未完成统一协调。但各份州级地质图所包含的地质数据均已实现标准化，可支持国家级尺度下的岩性、年代与地层学空间分析。有关本数据集制作流程与方法的完整说明可参阅随附报告：Horton J.D.、San Juan C.A.与Stoeser D.B.于2017年发表的《美国本土州地质图汇编（SGMC）地理数据库》，载于美国地质调查局数据系列1052，共46页，链接：https://doi.org/10.3133/ds1052。