Magna 50 — Geological Map of Spain at 1:50.000 (2nd Series)

The National Geological Map (MAGNA), carried out between 1972 and 2003 by the Geological and Mining Institute of Spain, is distributed in sheets 1:50.000 (1:25,000 in the particular cases of the Canary Islands, Ibiza-Formentera, Menorca, Ceuta and Melilla). The Geological Map depicts the nature of the materials (rocks and sediments) that appear on the earth’s surface, their spatial distribution and the geometric relations between the different cartographic units. A geologic cartographic unit is the grouping of one or more lithologies with a common age range, which has representation on the map at a defined scale or resolution. Each cartographic unit, as well as the different geological structures, are represented on the map with its own symbology. The representation of these units on the topographic basis of the map, provides certain three-dimensional information that is completed with other geological data such as geological cuts, stratigraphic profiles, surveys, etc. The legend of the map is a pictogram that represents the spatial relationship of the different cartographic units (chronology, superposition, geometric relationship, lateral changes of facies, etc.). It also includes structural, hydrogeological and geological location schemes of the leaf within its regional scope.西班牙地质与矿业研究所（Geological and Mining Institute of Spain）于1972年至2003年间编制的国家地质图（National Geological Map，缩写MAGNA）以分幅形式发布，标准比例尺为1:50000；仅在加那利群岛、伊比萨-福门特拉岛、梅诺卡岛、休达及梅利利亚等特殊区域采用1:25000的比例尺。该地质图旨在表征地表出露物质（岩石与沉积物）的属性、空间分布特征，以及不同制图单元间的几何关系。 地质制图单元是指具有共同年代范围的一种或多种岩性的集合体，可在特定比例尺或分辨率下于图面中呈现。每个制图单元以及各类地质构造，均通过专属的符号系统在图中进行表达。将这些单元绘制在地形图底图之上，可提供一定的三维空间信息，此类信息可通过地质剖面、地层剖面、野外勘测等其他地质数据进行补充完善。 地图图例以象形符号的形式，阐释不同制图单元间的空间关系，包括年代序列、叠置关系、几何关联以及岩相侧向变化等内容。图例还包含对应分幅在其所属区域范围内的构造、水文地质及地质位置示意图。