Map showing lava flows in the southeast part of the Phoenicis Lacus Quadrangle of Mars

The Systematic mapping of lava flow units in the Tharsis region has been compiled into a series of 16 maps at 1:2,000,000 scale. This work provides information on the sources and areal extent of the lava flows, on their eruptive sequences and relative ages, and on relations between the flows and geologic structure in the largest, most active tectonic and volcanic province on Mars. Some of the maps were made from controlled Viking photomosaics published as quarter quadrangles in the Atlas of Mars Topographic Series (U.S. Geological Survey, 1979) and tied to the Viking control net. Where these photomosaics were not available, larger scale catalog photomosaics tied to the Mariner 9 control net were used. These maps were subsequently reduced to the 1:2,000,000 scale, but slight discrepencies may occur in places between features referred to coordinates on the two types of bases.

塔尔西斯（Tharsis）区域熔岩流单元的系统性填图成果已汇编为一套共计16幅、比例尺为1:200万的地图。本成果提供了火星规模最大、活动性最强的构造-火山省境内的熔岩流源区、分布范围、喷发序列、相对年龄，以及熔岩流与地质构造间的相互关系等相关信息。部分地图基于经控制点校正的维京号（Viking）摄影镶嵌图制作而成，该类镶嵌图以《火星地形系列图集》（美国地质调查局（U.S. Geological Survey），1979）中的四分之一四边形区块形式发布，并匹配至维京号控制网。若无法获取上述摄影镶嵌图，则采用匹配至水手9号（Mariner 9）控制网的大比例尺图集摄影镶嵌图。后续上述地图均被缩制至1:200万比例尺，但在部分区域内，基于两类基准坐标系的地物坐标可能存在细微偏差。