ILLUSTRATION 21: AERIAL VIEW OF PROJECT SITE TOPOGRAPHIC SURVEY ALIGNMENT <strong>The</strong> <strong>Mountain</strong> <strong>Pine</strong> <strong>Ridge</strong> Granite Quarry EIA / Ecoworks Page 38 of 167
Topsoil textures in the Pinol subsuite vary from loamy coarse sand to clay loam, but mainly occur in the sandy loam-sandy clay loam range and are weak or moderate crumb or fine blocky with a tendency to break to single grain in the coarsest soils or to fine crumb in most of the others. Subsoil colors tend to get redder with depth, a common sequence being brownish yellow over yellowish red, with textures varying from sandy loam to clay, with sandy clay being predominant. Lower subsoil becomes more mottled with depth and grades into variegated red, white, yellow and brown weathering granite, but also may demonstrate manganiferous staining from weathering, particularly along joint planes. (see Illustration 21: Lower left photo: surface boulders with manganiferous staining from weathering; Lower right photo: weathering granite along Pinol Creek). In the western <strong>Mountain</strong> <strong>Pine</strong> <strong>Ridge</strong>, there is a discontinuous band of deeper and wetter granitic soils, apparently formed in hillwash or alluvium deposited by streams flowing westwards towards the Macal River. Beneath shallow darkened topsoil, the profile consists of pale colored loamy sandsandy clay. Matrix colors are yellow, light grey or white, often with yellow, brown and black mottles. <strong>The</strong> soil is moist in the upper horizons but quite wet at depth. Subsoil structures are weakly blocky and consistencies are friable-loose. <strong>The</strong> wet lower subsoil continues to well below 1.5 meters depth, sometimes taking on greenish tinges’ in the matrix colors. Pinol subsuite soils can be readily distinguished from related varieties by the presence of plentiful angular quartz grit in the solum and the presence of underlying weathering granite rather than medasediments. Further, Pinol subsuite soils demonstrate more pronounced subsoil compaction, are associated with pine savanna rather than broadleaf forest, and are generally restricted to the <strong>Mountain</strong> <strong>Pine</strong> <strong>Ridge</strong> at altitudes of 500 meters above MSL. <strong>The</strong>re are also a number of limitations to their agricultural suitability, which include compaction and acidity, which make inhospitable root environments; as well as nutrient deficiencies and imbalances. <strong>The</strong>se characteristics also impede soil suitability for timber production, as the logging return on pine is on the order of 50 to 70 years. King et al (1992) went on to recommend that soils of the <strong>Mountain</strong> <strong>Pine</strong> <strong>Ridge</strong> in general should be maintained under forest, with greater attention paid to their suitability for recreation and tourism. Moreover all systems of management should take note of erodibility of the soils, especially in view of the importance of the <strong>Mountain</strong> <strong>Pine</strong> <strong>Ridge</strong> as a major source of surface water for much of central Belize. Soil Percolation Two in situ soil percolation tests were conducted on the project site (see Illustrations 22 - 23), and returned findings that were consistent with the reported soil stratigraphy for the area. <strong>The</strong> first test was conducted near to the camp site at the northeastern corner of the mining site, which returned a percolation rate of approximately 25 meters per hour. compared with the findings of the remaining two test sites that were approximately equal at approximately 7 meters per day. <strong>The</strong> second test was conducted near to the material excavation site at the southwestern portion of the mining site, which returned a percolation rate of approximately 50 meters per hour, and was a likely result of the coarse-grained soil at the site. Both percolation rate returns are adequate for leachfield use; however the faster rate of the second site, which is consistent with the test site being located on the side slope rather than plain of the pine savanna, suggests percolation in this area may worsen area potential for subsoil erosion, and hence be unsuitable for locating sewage leachfields. <strong>The</strong> <strong>Mountain</strong> <strong>Pine</strong> <strong>Ridge</strong> Granite Quarry EIA / Ecoworks Page 39 of 167
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