2.11b (100.61 ha Index 26)
They are rocky mountain ranges with a strongly undulating landscape and slopes greater than 20%. In the first case, it exists in discontinuous patches, correlated with intrusive granites, where the percentage of rockiness reaches between 10 and 40% of the area with exposed rock. The dominant soils are Subeutric Melanic Lithosols, gravelly sandy, sometimes stony and very superficial; with rocky outcrops and Haplic Subeutric Brunosols, sandy gravelly loam and gravelly loam, superficial, stony (Regosols). They may present mountainous mountains. In the second case, the landscape is broken with slopes greater than 15% that can reach values of 30 to 40%, being characteristic of the hills belonging to the Sierra de Aigua and the broken landscapes existing south of the city of Minas, observable by Route 60. Mostly this situation is correlated to lithologies corresponding to the group Lavalleja and undifferentiated metamorphic rocks. In general, in the association of soils, the superficial ones predominate (District Subeutric Lithosols), existing in the concavities and gorges, deep soils, of colluvial origin that normally contain high-density mountain forest. The use is pastoral and the vegetation is grassland with a predominance of summer species, with associated weeds (Baccharis trimera, etc.). This group integrates the Santa Clara and Sierra de Aigua units of the chart at a scale of 1:1.000.000 (DSF).
2.21 (48.64 ha Index 105)
The relief is hilly, with convex interfluves and slopes between 6 and 12%. The soils are Luvic Brunosols (maximal Brown Grasslands), loams and Abruptic Melanic Subeutric Argisols, sometimes moderately deep loams (Planosolic Grasslands). Brunosols occur on convex or flat slopes, while Argisols are related to the softer upper zone of the interfluves. This soil pattern occurs in the south of the Department of Treinta y Tres and north of Rocha, while in the south of Rocha y Maldonado Brunosols with finer textures and greater natural fertility dominate. Associated with these, thinner soils occur: moderately deep rhodic Luvic Brunosols (Red Prairies) and occasionally Melanic Subeutric Lithosols, sometimes very superficial. Both are related to more dissected areas or eruptions, or to proximity to rocky outcrops. The mother material is made up of a weak mantle (sometimes discontinuous) of Quaternary clayey silt sediments on the crystalline basement rock. The vegetation is predominantly summer grassland, and the current use is pastoral. It occupies important areas to the west and southwest of Treinta y Tres, surroundings of Velazquez and south of the Department of Maldonado. The soils in this group correspond to the Jose Pedro Varela unit of the chart at a scale of 1:1.000.000 (DSF).
2.11a (21.21 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).
2.12 (16.55 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.
