Summary of recommendations of nomenclature committees relevant to clay mineralogy: report of the association internationale pour l'etude des argiles (AIPEA) Nomenclature Committee for 2006.

Recently Kogure and co-workers published several papers reporting the stacking structures of various 2:1 layer phyllosilicates (e.g., aspidolite, Kogure et al., 2004; wonesite, Kogure et al., 2005; pyrophyllite, Kogure et al., 2006), mainly by using high-resolution TEM. However, there is ambiguity in wording that refers to the lateral displacement between two tetrahedral sheets across the interlayer regions. Zvyagin et al. (1969) used the symbol "" for this displacement, which describes the structures of pyrophyllite and talc, but no universally accepted wording was used for other 2:1 phyllosilicates or 1:1 phyllosilicates. Bailey (1984, p. 32) referred to the "layer offset" for this displacement in mica, but the original meaning of “layer offset” can be taken as the "displacement" to offset the intralayer shift of the 2:1 layer. A more precise meaning of these terms is needed that can be applied to not only the micas, but other 2:1 layer phyllosilicates also. Recommendations are also included for 1:1 layers

Chemical Weathering

Living reference work entry First Online: 22 July 2017 Definition: Weathering of rocks caused by the chemical action of water containing atmospheric oxygen, carbon dioxide, and some organic acids in solution on the rock-forming minerals leading to an adjustment of the mineralogical composition with the formation of new minerals, like hydrous phyllosilicates, iron oxides/hydroxides, soluble salts, and other alteration products, consisting in rocks decay by their chemical decomposition. Introduction: Chemical processes need water, being carried out more rapidly at higher temperature, so they are common in warm and wet climates. There are different types of chemical weathering processes , such as solution, hydration, hydrolysis, carbonation, oxidation, reduction, and chelation. Some of these reactions occur more easily when the water is slightly acidic. Weathering of rocks is a fundamental phenomenon for the formation of the soil,... This is a preview of subscription content, log in to check access Copyright information © Springer International Publishing AG 201