10.3 (15.90 ha Index 140)
It develops throughout the large region of the crystalline basement, expressing itself as discontinuous, slightly convex interfluves, with cusp flattenings with water holes and sporadically small rocky outcrops. It is a frequent group in the Carreta Quemada area (Department of San Jose), Cuchilla de Villasboas south of JJ Castro (Department of Flores) and at the intersection of Route 6 and Cuchilla Grande (Camino Cerro Colorado Hernandarias in the Department of Florida). The geological material is a thin clayey silt sediment 0,50-2 meters thick in contact with lithologies of the crystalline basement from which it inherits coarse sands and gravel. The relief is gently undulating, with slopes of 1 to 3%. The dominant soils correspond to Eutric Luvic Brunosoles (Medium to Maximum Very Dark Brown Grasslands), black or very dark brown in color, loamy to clay loam texture, high fertility and moderately well drained. Associated there are Typical Eutric Brunosols (Black Vertisolic Prairies) and Luvic Ruptic Vertisols (Grumosoles). The predominant use is pastoral, although forage crops are frequent in the area corresponding to the dairy basin. These areas are integrated into the units. Carolina and Mala Island on the map at a scale of 1:1.000.000 (DSF). In the Capilla del Sauce area (Department of Florida), the association of soils corresponds to Luvic Ruptic Vertisols (Grumosoles) with Luvic Subeutric Brunosols (medium to maximum Brown Grasslands), sodic. This region is integrated into the Montecoral unit of the chart at a scale of 1:1.000.000 (DSF).
5.02b (10.10 ha Index 88)
It is the most important group, since it occupies more than 80% of the lands in this subzone. It exists repeatedly in the Departments. of Florida and in the Department of Flores (Tips of the San Jose) and in the rest of the region defined for zone 5. The relief is undulating and strongly undulating, with modal slopes of 5 to 7%. The geological material corresponds to variable lithologies of pre-Devonian rocks, such as granites, migmatites, schistose metamorphic rocks (around Rosario), etc. The soils are moderately deep and superficial Subeutric Haplic Brunosols (moderately deep Brown Grasslands and Regosols), to which Inceptisole (Lithosols) are associated, sometimes very superficial. The upper horizon is brown and reddish brown, sometimes yellowish brown, with a loamy texture, gravelly loam or sandy loam with abundant gravel, fertility is medium, sometimes low. The rockiness is moderate and varies between 2 to 10% of the area with outcrops. Throughout the area there may be narrow lowlands, associated with drainage routes of little importance, which contain hydromorphic Luvic Gleysols (Humic Gley) and Typical Eutric or Luvic Brunosols (Black Prairies and Maximal Brown Prairies), which contain very good summer pastures. The use is pastoral. This group corresponds to the San Gabriel-Guaycuru unit on the 1:1.000.000 (DSF) scale chart.
