(LAC-41) Geologic map of the Montes Apenninus region of the Moon

Material exposed on the surface of the Moon is heterogeneous. The albedo and other physical characteristics that have been determined with the use of optical and radio telescopes vary from one part of the Moon to another, and the variations are partially correlated with differences in topography. Discontinuities in the areal variation permit the surface material to be divided into map units, each exhibiting a limited range of photometric properties associated with a limited range of topographic characteristics. Each map unit is further characterized by a distinctive pattern of distribution, and the patterns of certain units are in places superimposed on the patterns of other units. From the relations of superposition it is possible to determine the sequence in which the units were formed.

月球表面暴露的物质具有非均质性。借助光学望远镜与射电望远镜测得的反照率（albedo）及其他物理特征，在月球各区域间存在差异，且此类差异与地形起伏的不同存在部分相关性。空间分布变异中的间断性可将表面物质划分为若干制图单元，每个单元均表现出特定范围的光度特性（photometric properties），并与特定范围的地形特征相关联。各制图单元还具有独特的分布格局，部分单元的分布格局在局部区域叠置于其他单元的分布格局之上。通过解析这些叠加关系，可推导出各制图单元的形成时序。