XRD Lab Experiment Assignment 4: Chemical Stages

Lab Experiment 4
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Lab Experiment 4
Question 1
The primary mineral for the Ah-Cu horizons mainly comprises the calcite especially on the A and B horizons of the old soils. Other minerals include plagioclase, feldspar, hematite, and orthoclase due to the hydrolysis. Furthermore, more quartz is familiar though they are minimal due to the Si dissolutions. The clay mineral for the Ah-Cu horizon includes illite due to the presence of biota especially at the A and B horizon followed by the illite-smectite and kaolinite with less halloysite due to energetic weathering. Furthermore, chlorite appears from the hydrothermal rocks as well as the vermiculite (Jackson, 1965). Lastly, smectite remains abundant due to the presence of biota that influences the stability of the soil. A result of landslide deposits and leaching indicate the usual Ah horizon with changes in the clay mineralization genesis and their transition down the slope of the profiles B and C horizons. The XRD X-ray results from the different figures indicate the clay combinations and their shifts from parent Cuk material. The combination of clay soils from the figures three, four and five adopted for the experiment (parent material (Cuk) in the R43 profile, Ck horizon of the R43 profile and BM horizon in the R43 profile) indicate similar consistency in the quantities of the various constituents of the clay soils. The components of the x-ray diffraction study reveal the presence of illite, quartz, plagioclase, calcite, hematite, kaolinite, chlorite, smectite and metahalloysite as the major phases. The four stages of illite are chemically identical (Latifi et al., 2017).
The elements portray differences in the diffraction patterns from the figures due to the differences in the crystal structures. In figure 3, the illite elements have no long-range atomic order hence produce broad scattering picks as in dictated in the parent material (Cuk) in the R43 profile. However, the components such as quartz, hematite, calcite, and plagioclase have long-range atomic order especially the quartz and plagioclase while hematite and calcite have medium range atomic order. The high atomic orders result in peak height X-ray intensities with a large area under the peak intensity curve (Latifi et al., 2017).
The parent material (Cuk) in the R43 profile gives the glycol, and air dry runs with no elements apart from the illite. However, both Ck horizon of the R43 profile and BM horizon in the R43 profile have smectite, chlorite, kaolinite, metahalloysite, and illite-smectite. Such combinations come as a result of leaching from the parent material and volcanic activities among others. However, as leaching takes place, there are usually shifts in angle as revealed through X-ray diffraction as a result of rotation of the samples. Such rotations occur less than the 2θ and do not go below 5° or above 70°. Therefore, Ck horizon profile and BM horizon profiles give a mixed layer of clays and the dislocation density (Latifi et al., 2017).
The unexpected presence of calcite in the Ck and Cuk horizon and its absence in BM horizons is due to the soil hydrological changes that affected the wetting depth in the different deposits as well as the formation o...