Eurasian Plate North American Juan de Fuca Plate San Andreas Caribbean Arabian Plate ilippine Plate Pacific Plate Indian-Australian Plate Nazca Plate African Plate American Plate Antarctic Plate Antarctic Plate Direction of plate motion Subduction zone (sawteeth point toward Spreading ridge overriding plate) Transform fault
Weathering Weathering -Factors bringing about fragmentation or chemical change of parent material (reducing the size of the particle) Mechanical weathering Chemical weathering
Weathering • Weathering - Factors bringing about fragmentation or chemical change of parent material (reducing the size of the particle). – Mechanical weathering – Chemical weathering
Mechanical weathering-Results from physical forces reducing size of rock particles without changing the chemical nature of the rock Freezing& Thawing temperature changes abrasion of rock particles( caused by force that move and rub rock particles against each other O wind and moving water also move small particles and deposit them at now location, exposing new surface to the weathering process
- temperature changes - abrasion of rock particles ( caused by force that move and rub rock particles against each other) - wind and moving water also move small particles and deposit them at now location,exposing new surface to the weathering process Mechanical weathering- Results from physical forces reducing size of rock particles without changing the chemical nature of the rock
Chemical weathering-chemical weathering involves the chemical alternation of the rock in such a manner that it is more likely to fragment or to be dissolved some small rock fragment may combine with oxygen from the air(when it was exposed to the atmosphere) and chemically change to different compounds some small rock may combine with water molecules (hydrolysis) the oxidized or hydrolyzed molecules are more readily soluble in water and, therefore, may be removed by rain or moving water. 氧化态或水解态岩石分子更易于在水中溶解,因此,它们可随 降雨或水流而迁移
- some small rock fragment may combine with oxygen from the air (when it was exposed to the atmosphere) and chemically change to different compounds. - some small rock may combine with water molecules (hydrolysis) Chemical weathering- chemical weathering involves the chemical alternation of the rock in such a manner that it is more likely to fragment or to be dissolved - the oxidized or hydrolyzed molecules are more readily soluble in water and, therefore, may be removed by rain or moving water. 氧化态或水解态岩石分子更易于在水中溶解，因此，它们可随 降雨或水流而迁移
Soil and land Land- Portion of world not covered by water Soil -a thin covering over the land consisting mixture of minerals, organic material, living organisms, air, and water Soil formation-a combination of physical, chemical and biological process over time the soil building begins with the fragmentation of the parent material Parent material -ancient layers of rock, or more recent geologic deposits from lava(4) flows or glacial activity
Soil and Land • Land - Portion of world not covered by water. • Soil – a thin covering over the land consisting mixture of minerals, organic material, living organisms, air, and water. • Soil formation – a combination of physical, chemical and biological process over time – the soil building begins with the fragmentation of the parent material – Parent material - ancient layers of rock, or more recent geologic deposits from lava (熔岩） flows or glacial activity