Geological Structure Contours, 1:24,000 Scale

Stuctural contours of varying datum digitized from the 1:24,000 Geologic Map Series maps. Structural contours were constructed by geologic map authors when the original geologic maps were published during the Kentucky geologic mapping program (Kentucky Geological Survey - U.S. Geological Survey from 1960 to 1980). Contoured formations were determined by the quadrangle map author, so contour datum may vary across quadrangle boundaries. Therefore contours are not based on the most recent subsurface data and should only be used as a general guideline for the underlying geologic structure. Contours are in feet above sea level, and may vary in contour interval across quadrangle boundaries. Please note that some contours are projected above the land surface.本数据集为从1:24000地质图系列（Geologic Map Series）原图数字化得到的不同基准面构造等值线（structural contours）。构造等值线由1960年至1980年间肯塔基地质填图项目（由肯塔基地质调查局（Kentucky Geological Survey）与美国地质调查局（U.S. Geological Survey）联合开展）所发布的原始地质图编制者绘制。等值线所对应的地层由对应图幅（quadrangle）的编制者确定，因此不同图幅边界处的等值线基准面可能存在差异。本套等值线未采用最新的地下实测数据，仅可作为推断地下地质构造的一般性参考依据。等值线单位为海拔英尺，且不同图幅边界处的等值线间距也可能存在差异。请注意，部分等值线的投影位置高于地表。