Geologic map of the Valles Marineris region, Mars

The Valles Marineris region lies east of Tharsis Montes (which extend from lat 12 degrees to 16 degrees., long 101 degrees to 125 degrees). Part of the region is in the midst of a vast plateau bounded on the west and east by Claritas and Nectaris Fossae, respectively; the remainder extends farther east into southern Xanthe Terr and western Margaritifer Terra. Channel trends, stereophotogrammetry, and radar altimetery indicate that the surface north and east of the canyons slopes toward Chryse Planitia (centered at about lat 25 degrees N., long 45 degrees). Within the broad Valles Marineris region, three distinct physiographic provinces are recognized (fig. 1): (1) the Noctis Labyrithus province, consisting of a high plateau cut by a network of structurally controlled troughs; (2) the Valles Marineris province, characterized by broad, linear valleys hundreds of thousands of kilometers long; (3) the eastern canyon province, containing irregular depressions as much as 900 km across. Topography has been determined from a preliminary stereophotogrammetric map having a contour interval and a precision of about 1 km (Wu and others, 1986) and from latitudinal tracks of radar altimetry have a precision of 200 m (Roth and others, 1980).

水手峡谷（Valles Marineris）区域位于塔尔西斯山群（Tharsis Montes）东侧，该山群的纬度范围为12°至16°，经度范围为101°至125°。该区域部分区域坐落于一处广阔高原之中，高原西侧与东侧分别以克拉里塔斯槽沟（Claritas Fossae）与涅卡里塔斯槽沟（Nectaris Fossae）为界；剩余区域则向东延伸至幸神台区（Xanthe Terra）南部与珍珠湾区（Margaritifer Terra）西部。通过河道走向、立体摄影测量法（stereophotogrammetry）与雷达测高法（radar altimetery）的分析结果可知，峡谷北侧与东侧的地表朝向克里斯平原（Chryse Planitia）倾斜，该平原中心坐标约为北纬25°、东经45°。
在广阔的水手峡谷区域内，可划分出三个独立的地貌省（physiographic provinces）（见图1）：(1) 诺克提斯迷宫（Noctis Labyrithus）省，主体为被构造槽网切割的高原；(2) 水手峡谷省，以绵延数十万千米的宽阔线性谷地为典型特征；(3) 东部峡谷省，内部存在直径可达900千米的不规则凹陷。
本研究的地形数据来源于两项测量成果：其一为等高距与精度均约1km的初步立体摄影测量地形图（Wu等，1986）；其二为精度达200m的雷达测高纬度轨迹数据（Roth等，1980）。