2.12 (101.96 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.
3.54 (8.39 ha Index 105)
It includes the continental plains located mainly on the Lascano-Cebollati route and on Route 9 between Rocha and Castles The relief is flat with weak meso-relief. The dominant soils are Melanic Subeutric Planosols, with loamy and silty textures, deep, imperfect drainage and medium fertility. Associated with these soils are Abruptic Eutric/Subeutric Melanic Argisols (maximum hydromorphic Brown Grasslands), with silty and clayey silt textures, deep, imperfectly drained and of medium fertility, and Typical Melanic Humic Gleysols (Gley humicos), silty and clayey silt, poorly drained and of medium to high fertility. The mother material is made up of clayey silt mudstones belonging to the Dolores formation. The vegetation is summer grassland, with a moderately dense cover and the current use is mainly rice and livestock. This group corresponds to the Lascano unit on the 1:1.000.000 (DSF) scale chart.
2.21 (1.59 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).
2.10 (0.07 ha Index 9)
It corresponds to very rocky mountain ranges and flattened rocky mountain ranges, with a general SW-NE orientation. The flattened rocky mountain ranges constitute the highest parts of the group, and their surface has a high density of outcrops (more than 40%), while the very rocky mountain range rocky constitutes high interfluves, strongly undulated with abundant outcrops. The underlying rocks are generally intrusive granites; quartzite components of the group Lavalleja and acid effusive rocks. The soils are District Umbrian (sometimes Subeutric) or Melanic Lithosols, gravelly and usually very superficial, with sandy or gravelly sandy textures, with moderately deep Typical Subeutric Brunosols as accessory soils. The rockiness is very high and more than 40% of the surface It is covered in outcrops. The current use is pastoral. There are important areas of this group in the Sierra de Carape and the Sierra de la Coronilla, to the E. and SE. of Aigua, Sierra de Animas, and isolated hills such as Marmaraja, Arequita, etc. This The group includes the soils of the Carape and Sierra de Animas units, and some of the Sierra de Aigua unit on the chart at a scale of 1:1.000.000 (DSF).
