Download Chapter 1

Soil Science
Chapter 2. Formation of soil from parent materials (*: important concept)
Zueng-Sang Chen (陳尊賢)
Tel: 2369-8349, [email protected]; http://Lab.ac.ntu.edu.tw/soilsc/
Printed on Sep. 10, 2004
2.1 Weathering of rocks and minerals
 *Rocks are classified as igneous, sediments and metamorphic rocks
 *Geology of Taiwan http://www.gl.ntu.edu.tw/
 Weathering sequence: Table 2.2, p34
 General case of weathering: (Fig 2.4, p35)
2.2 Physical weathering
2.3 *Biogeochemical weathering: hydration, dissolution, carbonate and acid reaction, oxidation-reduction,
complexation
2.4 *Factors influencing soil formation: parent materials, climate, biota, topography, time, and human
2.5 Parent materials: (Fig 2.10, p 41)
2.7 Colluvial debris: Colluvium (崩積)
2.8 *Alluvial stream deposit: fllodplain, alluvial fans, delta deposit.
 Alluvial soils of sandstone, shale, slate, schist in Taiwan. http://Lab.ac.ntu.edu.tw/soilsc/
2.13 Climate:
 Precipitation: fall per month and per year (Box 2.1, p55)
 *Climate affects on the vegetation types (Fig 2.24, p56)
 Air temperature and air temperature
2.14 Biota:
 *Soil types affected by grassland and forest vegetation (Fig 2.25, p57)
 Coniferous types of tree and deciduous type of three
 *Role of animals: earthworms, termites, (pedoturbation), and human activities.
2.15 *topography (Fig 2.29, p61), five landscape positions of topography (Fig 2.30, p62)
2.16 *Time: examples of soil genesis over time (Fig 2.31, p63)
2.17 *Four basic process of soil formation: transformation, translocation, addition, and loss (Fig2.32, p65)
2.18 Soil profile (Fig 2.35, p69)
 *Eluviation: clay, organic C, soluble salts, Fe, Al
 Illuviation
 Master horizon (Table 2.6, p71)
Discussion:
1. Explain the significance of Si/Al ratio in soil minerals
2. Explain the five factors affecting the soil formation.
3. Explain the four broad processes of soil formation
4. The master horizon formed in the humid and tropical forest regions
5. The master horizons formed in the cold and humid coniferous vegetation region.
6. Please predict the formation time of red soils in the terrace of Linko, ChungLee, Da-Du-Shan, and
Kengtin.