5.02b (58.52 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.
11.9 (46.08 ha Index 201)
This group is located discontinuously in the south of the Department of Colonia and it is observable along Route 1, in the vicinity of Nueva Helvecia. They also appear in the Department of San Jose, the last areas existing around Ecilda Paullier. The geological material corresponds to sediments from the Fray Bentos formation, which in some places appears with tilloid characteristics, since in its mass there are gravel, gravel and stones of lithologies corresponding to the crystalline basement. There is also fine-grained lithological contribution from the Quaternary sediments that occupy the interfluves and gradually decrease in thickness, until they disappear, on the dissected slopes characteristic of this group. The relief is made up of steep slopes that form a dissection front with slopes of 4 to 8%. The predominant soils are Subeutric Brunosols, sometimes Eutric, Typical, sometimes Luvic (medium to maximum Brown Grasslands), dark grayish brown in color, clay loam to heavy sandy loam texture, medium fertility, sometimes high and moderately well drained. The predominant use of the land is with winter-summer crops and forage for dairy, with average farm sizes and, in general, with many years of agriculture, so the characteristics of the natural field vegetation cannot be pointed out. This group is part of the Ecilda Paullier - Las Brujas unit on the 1:1.000.000 (DSF) scale chart.
03.3 (10.81 ha Index 96)
This group corresponds to the plains of rivers and streams that occur associated with hills of crystalline basement. An example is the existing plain in the Arroyo Santa Lucia Chico. The geological material corresponds to clayey silt sediments and, close to water courses, alluvial sediments of variable textures and stratified. They are rapid and short-duration flood plains, with meso-relief, showing channels and meanders, typical of their fluvial origin. The dominant soils correspond to Eutric Melanic Planosols, sometimes cumulic, very dark brown to black in color, silty loam and when cumulic, silty clay, very high fertility and imperfect drainage, and Gleysols, Typical Luvic, Melanic, black to black in color. very dark gray, silty clay loam or silty clay, very high fertility and poor drainage. The use is pastoral, with summer meadow vegetation and in the humid areas hydrophilic and uliginous communities are associated. In the riparian areas, with Heterotextural Fluvisols (Alluvial Soils), there is the typical river forest throughout the country. This group, for reasons of scale, is included in the San Gabriel - Guaycuru unit on the map at a scale of 1:1.000.000 (DSF).
