How Do Soils Form? Examining Rocks, Minerals, and the Products of Weathering Under a Microscope

This lab focuses on the theoretical background of soil formation, including the processes involved in creating soil from mineral and organic parent materials. Soil forming processes include additions, losses, translocation, and transformation. The factors that affect soil formation are climate, hydrology, topography, parent materials, time, and organisms, with humans acting as an additional factor in urban environments. The lab procedure involves examining hand specimens and microscopic minerals to identify the nutrients originating from the minerals and rocks. Additionally, different types of soil and gravel are examined under a microscope to determine the presence of minerals based on parent rocks and to compare and contrast different soils and sands. The mineral composition of soils is a product of local parent materials and transported materials, and soil properties such as texture and fertility directly depend on the rocks from which the soil formed. Soil plays crucial roles in the urban ecosystem, including providing habitat for organisms, recycling nutrients, purifying water, supporting gas exchange with the atmosphere, creating foundations for infrastructure, and supporting urban garden produce.