2.11a (210.66 ha Index 53)
They are rocky mountain ranges with a strongly undulating landscape and slopes between 5 and 20%. The geological materials are basically made up of igneous, metamorphic and some acidic effusive rocks, and the rockiness can reach levels of up to 10%. In this group, two regions with different soil associations must be established: a) The southern region, (Departments of Lavalleja, Maldonado, Rocha and part of Treinta y Tres), where the dominant soils are Haplic Subeutric Brunosols, sandy gravelly loam and gravelly loam, superficial, stony (Regosols). Associated with these, Typical Subeutric Brunosols occur, loamy, moderately deep, sometimes deep (moderately deep Brown Prairies), in some cases to lithic contact; and Melanic Subeutric Lithosols, gravelly sandy, sometimes stony and very superficial; with rocky outcrops. The Brunosols (Haplic and Typical) together occupy more than 70% of the area and develop among the outcrops of rocks, mainly migmatites and intrusive granites, while the Lithosols occur close to the outcrops, or in the rockiest areas of the unit. . b) The northern region, (Departments of Cerro Largo and north of Treinta y Tres) in which the dominant soils are Umbrian Inceptisols, sandy loam, gravelly, sometimes stony, superficial and moderately deep, acidic with variable aluminum contents. Associated with these, there are District, Umbrian, sandy loam, gravelly and acid Lithosols. The vegetation is summer cycle grassland and associated shrublands, and the use is pastoral. This unit occupies important areas of the Sierra de los Rios, extensive areas between Valentines, Tupambae and Treinta y Tres, surroundings of Aigua, etc. The soils are members of the Santa Clara unit and part of the Sierra de Aigua unit of the chart at a scale of 1:1.000.000 (DSF).
2.13 (78.03 ha Index 92)
They are flattened non-rocky mountain ranges, associated with undulating non-rocky mountain ranges, with extended flattened or slightly undulating interfluves in the upper part with slopes of 1-2% and slopes of 4-8% on the steeper slopes. The geological material corresponds to granitic rocks, more altered than in the previous units, sometimes covered with very thin sediments completely edified. The soils are typical Subeutric Brunosols, loamy, deep and moderately deep, sometimes with pseudolithic contact (shallow Brown Grasslands) and Subeutric Haplic Brunosols, sandy loamy gravelly loam and superficial gravelly loam (Regosols). Associated with these, on the steeper slopes and close to the outcrops, Subeutric Melanic Lithosols occur, sandy loam gravelly, sometimes very superficial and stony. The vegetation is grassland with a predominantly summer cycle, with associated mountain scrub in the gorges and concave areas of greater slope. The current use is pastoral. It occupies areas around Cerro Chato, Valentines, Puntas del Olimar, west of Treinta y Tres and north of Maldonado. The soils of this group make up the Cerro Chato unit and an important part of the Sierra de Polanco unit of the 1:1.000.000 (DSF) scale chart.
2.12 (6.46 ha Index 83)
They are non-rocky mountain ranges with undulating and strongly undulating relief, with outcrops generally less than 5% and variable slopes between 5 and 15%. The soils are Haplic and Typical Subeutric Brunosols, sandy loams and loams, sometimes sandy gravelly loams, superficial and moderately deep, (Regosols and medium shallow Brown Prairies). Associated with these are Subeutric Melanic Lithosols, sandy-loamy-gravelous, sometimes very superficial and stony, and Subeutric Luvic Brunosols (Maximum Brown Prairies), loamy or occasionally sandy-loamy, sometimes rhodic (Red Prairies). The vegetation is predominantly summer cycle prairie, sometimes with associated scrub and mountain forest, generally in the gorges and concave areas. The current use is pastoral. It occupies large areas in the Departments. of Maldonado, Lavalleja, West of Treinta y Tres and southwest of Cerro Largo. The soils in this group are part of the Sierra de Polanco unit of the 1:1.000.000 (DSF) scale chart.
