Weathering of Minerals: Sequence, Products, Result and Stages

After reading this article you will learn about:- 1. Weathering Sequence of Minerals 2. Products of Weathering Minerals 3. Results 4. Stages.

Weathering Sequence of Minerals:

Climatic and biotic conditions will determine the relative stability of the various soil forming minerals. Under all climatic conditions a definite listing of minerals in relation to their resistance to weathering cannot be made. So considering the various environmental conditions and diversification the following order of weathering resistance of the sand and silt-size minerals are:

quartz (most resistant) > muscovite, K-feldspars > Na and Ca-feldspars >biotite hornblende and augite> olivine > dolomite and calcite > gypsum and it is subjected to change according to environmental conditions.

The order of crystallization from a structural point of view was found to as follows: independent tetrahedrons → single chains → double chains → sheets.

The relative stability of the minerals to weathering and to decomposition with acids also appears to be related to the degree of basicity, degree of linkage of the tetrahedrons, relative number of alumina and silica tetrahedrons and other factors that result a lowering of the basicity of the mineral and a destruction of bonds linking, the tetrahedrons.

The weathering sequence as reported by Goldich (1938) is presented in figure 3.2.

Products of Weathering Minerals:

The weathering products of most common rock-forming silicate minerals (Ferromagnesian and Non-ferromagnesian) are presented below:

Results of Weathering:

Stages in Weathering of Minerals:

The different stages in the weathering of soil minerals are depicted in Table 3.4